Major changes in RFC v5:
------------------------
1. Rebased on top of 'Abstract page from net stack' series and used the
new netmem type to refer to LSB set pointers instead of re-using
struct page.
2. Downgraded this series back to RFC and called it RFC v5. This is
because this series is now dependent on 'Abstract page from net
stack'[1] and the queue API. Both are removed from the series to
pre-requisite work.
3. Reworked the page_pool devmem support to use netmem and for some
more unified handling.
4. Reworked the reference counting of net_iov (renamed from
page_pool_iov) to use pp_ref_count for refcounting.
The full changes including the dependent series and GVE page pool
support is here:
https://github.com/mina/linux/commits/tcpdevmem-rfcv5/
[1] https://patchwork.kernel.org/project/netdevbpf/list/?series=810774
Major changes in v1:
--------------------
1. Implemented MVP queue API ndos to remove the userspace-visible
driver reset.
2. Fixed issues in the napi_pp_put_page() devmem frag unref path.
3. Removed RFC tag.
Many smaller addressed comments across all the patches (patches have
individual change log).
Full tree including the rest of the GVE driver changes:
https://github.com/mina/linux/commits/tcpdevmem-v1
Changes in RFC v3:
------------------
1. Pulled in the memory-provider dependency from Jakub's RFC[1] to make the
series reviewable and mergable.
2. Implemented multi-rx-queue binding which was a todo in v2.
3. Fix to cmsg handling.
The sticking point in RFC v2[2] was the device reset required to refill
the device rx-queues after the dmabuf bind/unbind. The solution
suggested as I understand is a subset of the per-queue management ops
Jakub suggested or similar:
https://lore.kernel.org/netdev/[email protected]/
This is not addressed in this revision, because:
1. This point was discussed at netconf & netdev and there is openness to
using the current approach of requiring a device reset.
2. Implementing individual queue resetting seems to be difficult for my
test bed with GVE. My prototype to test this ran into issues with the
rx-queues not coming back up properly if reset individually. At the
moment I'm unsure if it's a mistake in the POC or a genuine issue in
the virtualization stack behind GVE, which currently doesn't test
individual rx-queue restart.
3. Our usecases are not bothered by requiring a device reset to refill
the buffer queues, and we'd like to support NICs that run into this
limitation with resetting individual queues.
My thought is that drivers that have trouble with per-queue configs can
use the support in this series, while drivers that support new netdev
ops to reset individual queues can automatically reset the queue as
part of the dma-buf bind/unbind.
The same approach with device resets is presented again for consideration
with other sticking points addressed.
This proposal includes the rx devmem path only proposed for merge. For a
snapshot of my entire tree which includes the GVE POC page pool support &
device memory support:
https://github.com/torvalds/linux/compare/master...mina:linux:tcpdevmem-v3
[1] https://lore.kernel.org/netdev/[email protected]/T/
[2] https://lore.kernel.org/netdev/CAHS8izOVJGJH5WF68OsRWFKJid1_huzzUK+hpKbLcL4pSOD1Jw@mail.gmail.com/T/
Changes in RFC v2:
------------------
The sticking point in RFC v1[1] was the dma-buf pages approach we used to
deliver the device memory to the TCP stack. RFC v2 is a proof-of-concept
that attempts to resolve this by implementing scatterlist support in the
networking stack, such that we can import the dma-buf scatterlist
directly. This is the approach proposed at a high level here[2].
Detailed changes:
1. Replaced dma-buf pages approach with importing scatterlist into the
page pool.
2. Replace the dma-buf pages centric API with a netlink API.
3. Removed the TX path implementation - there is no issue with
implementing the TX path with scatterlist approach, but leaving
out the TX path makes it easier to review.
4. Functionality is tested with this proposal, but I have not conducted
perf testing yet. I'm not sure there are regressions, but I removed
perf claims from the cover letter until they can be re-confirmed.
5. Added Signed-off-by: contributors to the implementation.
6. Fixed some bugs with the RX path since RFC v1.
Any feedback welcome, but specifically the biggest pending questions
needing feedback IMO are:
1. Feedback on the scatterlist-based approach in general.
2. Netlink API (Patch 1 & 2).
3. Approach to handle all the drivers that expect to receive pages from
the page pool (Patch 6).
[1] https://lore.kernel.org/netdev/[email protected]/T/
[2] https://lore.kernel.org/netdev/CAHS8izPm6XRS54LdCDZVd0C75tA1zHSu6jLVO8nzTLXCc=H7Nw@mail.gmail.com/
----------------------
* TL;DR:
Device memory TCP (devmem TCP) is a proposal for transferring data to and/or
from device memory efficiently, without bouncing the data to a host memory
buffer.
* Problem:
A large amount of data transfers have device memory as the source and/or
destination. Accelerators drastically increased the volume of such transfers.
Some examples include:
- ML accelerators transferring large amounts of training data from storage into
GPU/TPU memory. In some cases ML training setup time can be as long as 50% of
TPU compute time, improving data transfer throughput & efficiency can help
improving GPU/TPU utilization.
- Distributed training, where ML accelerators, such as GPUs on different hosts,
exchange data among them.
- Distributed raw block storage applications transfer large amounts of data with
remote SSDs, much of this data does not require host processing.
Today, the majority of the Device-to-Device data transfers the network are
implemented as the following low level operations: Device-to-Host copy,
Host-to-Host network transfer, and Host-to-Device copy.
The implementation is suboptimal, especially for bulk data transfers, and can
put significant strains on system resources, such as host memory bandwidth,
PCIe bandwidth, etc. One important reason behind the current state is the
kernel’s lack of semantics to express device to network transfers.
* Proposal:
In this patch series we attempt to optimize this use case by implementing
socket APIs that enable the user to:
1. send device memory across the network directly, and
2. receive incoming network packets directly into device memory.
Packet _payloads_ go directly from the NIC to device memory for receive and from
device memory to NIC for transmit.
Packet _headers_ go to/from host memory and are processed by the TCP/IP stack
normally. The NIC _must_ support header split to achieve this.
Advantages:
- Alleviate host memory bandwidth pressure, compared to existing
network-transfer + device-copy semantics.
- Alleviate PCIe BW pressure, by limiting data transfer to the lowest level
of the PCIe tree, compared to traditional path which sends data through the
root complex.
* Patch overview:
** Part 1: netlink API
Gives user ability to bind dma-buf to an RX queue.
** Part 2: scatterlist support
Currently the standard for device memory sharing is DMABUF, which doesn't
generate struct pages. On the other hand, networking stack (skbs, drivers, and
page pool) operate on pages. We have 2 options:
1. Generate struct pages for dmabuf device memory, or,
2. Modify the networking stack to process scatterlist.
** part 3: page pool support
We piggy back on page pool memory providers proposal:
https://github.com/kuba-moo/linux/tree/pp-providers
It allows the page pool to define a memory provider that provides the
page allocation and freeing. It helps abstract most of the device memory
TCP changes from the driver.
** part 4: support for unreadable skb frags
Page pool iovs are not accessible by the host; we implement changes
throughput the networking stack to correctly handle skbs with unreadable
frags.
** Part 5: recvmsg() APIs
We define user APIs for the user to send and receive device memory.
Not included with this series is the GVE devmem TCP support, just to
simplify the review. Code available here if desired:
https://github.com/mina/linux/tree/tcpdevmem
This series is built on top of net-next with Jakub's pp-providers changes
cherry-picked.
* NIC dependencies:
1. (strict) Devmem TCP require the NIC to support header split, i.e. the
capability to split incoming packets into a header + payload and to put
each into a separate buffer. Devmem TCP works by using device memory
for the packet payload, and host memory for the packet headers.
2. (optional) Devmem TCP works better with flow steering support & RSS support,
i.e. the NIC's ability to steer flows into certain rx queues. This allows the
sysadmin to enable devmem TCP on a subset of the rx queues, and steer
devmem TCP traffic onto these queues and non devmem TCP elsewhere.
The NIC I have access to with these properties is the GVE with DQO support
running in Google Cloud, but any NIC that supports these features would suffice.
I may be able to help reviewers bring up devmem TCP on their NICs.
* Testing:
The series includes a udmabuf kselftest that show a simple use case of
devmem TCP and validates the entire data path end to end without
a dependency on a specific dmabuf provider.
** Test Setup
Kernel: net-next with this series and memory provider API cherry-picked
locally.
Hardware: Google Cloud A3 VMs.
NIC: GVE with header split & RSS & flow steering support.
Cc: Pavel Begunkov <[email protected]>
Cc: David Wei <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Yunsheng Lin <[email protected]>
Cc: Shailend Chand <[email protected]>
Cc: Harshitha Ramamurthy <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Jeroen de Borst <[email protected]>
Cc: Praveen Kaligineedi <[email protected]>
Jakub Kicinski (1):
net: page_pool: create hooks for custom page providers
Mina Almasry (13):
net: page_pool: factor out page_pool recycle check
net: netdev netlink api to bind dma-buf to a net device
netdev: support binding dma-buf to netdevice
netdev: netdevice devmem allocator
page_pool: convert to use netmem
page_pool: devmem support
memory-provider: dmabuf devmem memory provider
net: support non paged skb frags
net: add support for skbs with unreadable frags
tcp: RX path for devmem TCP
net: add SO_DEVMEM_DONTNEED setsockopt to release RX frags
net: add devmem TCP documentation
selftests: add ncdevmem, netcat for devmem TCP
Documentation/netlink/specs/netdev.yaml | 52 +++
Documentation/networking/devmem.rst | 271 +++++++++++++
Documentation/networking/index.rst | 1 +
arch/alpha/include/uapi/asm/socket.h | 8 +-
arch/mips/include/uapi/asm/socket.h | 6 +
arch/parisc/include/uapi/asm/socket.h | 6 +
arch/sparc/include/uapi/asm/socket.h | 6 +
include/linux/skbuff.h | 68 +++-
include/linux/socket.h | 1 +
include/net/devmem.h | 127 ++++++
include/net/netdev_rx_queue.h | 1 +
include/net/netmem.h | 223 ++++++++++-
include/net/page_pool/helpers.h | 117 ++++--
include/net/page_pool/types.h | 27 +-
include/net/sock.h | 2 +
include/net/tcp.h | 5 +-
include/trace/events/page_pool.h | 28 +-
include/uapi/asm-generic/socket.h | 6 +
include/uapi/linux/netdev.h | 19 +
include/uapi/linux/uio.h | 14 +
net/bpf/test_run.c | 5 +-
net/core/datagram.c | 6 +
net/core/dev.c | 314 ++++++++++++++-
net/core/gro.c | 7 +-
net/core/netdev-genl-gen.c | 19 +
net/core/netdev-genl-gen.h | 2 +
net/core/netdev-genl.c | 123 ++++++
net/core/page_pool.c | 419 +++++++++++++-------
net/core/skbuff.c | 92 ++++-
net/core/sock.c | 45 +++
net/ipv4/tcp.c | 196 +++++++++-
net/ipv4/tcp_input.c | 13 +-
net/ipv4/tcp_ipv4.c | 9 +
net/ipv4/tcp_output.c | 5 +-
net/packet/af_packet.c | 4 +-
tools/include/uapi/linux/netdev.h | 19 +
tools/testing/selftests/net/.gitignore | 1 +
tools/testing/selftests/net/Makefile | 5 +
tools/testing/selftests/net/ncdevmem.c | 489 ++++++++++++++++++++++++
39 files changed, 2527 insertions(+), 234 deletions(-)
create mode 100644 Documentation/networking/devmem.rst
create mode 100644 include/net/devmem.h
create mode 100644 tools/testing/selftests/net/ncdevmem.c
--
2.43.0.472.g3155946c3a-goog
From: Jakub Kicinski <[email protected]>
The page providers which try to reuse the same pages will
need to hold onto the ref, even if page gets released from
the pool - as in releasing the page from the pp just transfers
the "ownership" reference from pp to the provider, and provider
will wait for other references to be gone before feeding this
page back into the pool.
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Mina Almasry <[email protected]>
---
This is implemented by Jakub in his RFC:
https://lore.kernel.org/netdev/[email protected]/T/
I take no credit for the idea or implementation; I only added minor
edits to make this workable with device memory TCP, and removed some
hacky test code. This is a critical dependency of device memory TCP
and thus I'm pulling it into this series to make it revewable and
mergeable.
RFC v3 -> v1
- Removed unusued mem_provider. (Yunsheng).
- Replaced memory_provider & mp_priv with netdev_rx_queue (Jakub).
---
include/net/page_pool/types.h | 12 ++++++++++
net/core/page_pool.c | 43 +++++++++++++++++++++++++++++++----
2 files changed, 50 insertions(+), 5 deletions(-)
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 76481c465375..4c090e86e550 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -51,6 +51,7 @@ struct pp_alloc_cache {
* @dev: device, for DMA pre-mapping purposes
* @netdev: netdev this pool will serve (leave as NULL if none or multiple)
* @napi: NAPI which is the sole consumer of pages, otherwise NULL
+ * @queue: struct netdev_rx_queue this page_pool is being created for.
* @dma_dir: DMA mapping direction
* @max_len: max DMA sync memory size for PP_FLAG_DMA_SYNC_DEV
* @offset: DMA sync address offset for PP_FLAG_DMA_SYNC_DEV
@@ -63,6 +64,7 @@ struct page_pool_params {
int nid;
struct device *dev;
struct napi_struct *napi;
+ struct netdev_rx_queue *queue;
enum dma_data_direction dma_dir;
unsigned int max_len;
unsigned int offset;
@@ -125,6 +127,13 @@ struct page_pool_stats {
};
#endif
+struct memory_provider_ops {
+ int (*init)(struct page_pool *pool);
+ void (*destroy)(struct page_pool *pool);
+ struct page *(*alloc_pages)(struct page_pool *pool, gfp_t gfp);
+ bool (*release_page)(struct page_pool *pool, struct page *page);
+};
+
struct page_pool {
struct page_pool_params_fast p;
@@ -174,6 +183,9 @@ struct page_pool {
*/
struct ptr_ring ring;
+ void *mp_priv;
+ const struct memory_provider_ops *mp_ops;
+
#ifdef CONFIG_PAGE_POOL_STATS
/* recycle stats are per-cpu to avoid locking */
struct page_pool_recycle_stats __percpu *recycle_stats;
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index dd5a72533f2b..45bb4210412d 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -25,6 +25,8 @@
#include "page_pool_priv.h"
+static DEFINE_STATIC_KEY_FALSE(page_pool_mem_providers);
+
#define DEFER_TIME (msecs_to_jiffies(1000))
#define DEFER_WARN_INTERVAL (60 * HZ)
@@ -174,6 +176,7 @@ static int page_pool_init(struct page_pool *pool,
const struct page_pool_params *params)
{
unsigned int ring_qsize = 1024; /* Default */
+ int err;
memcpy(&pool->p, ¶ms->fast, sizeof(pool->p));
memcpy(&pool->slow, ¶ms->slow, sizeof(pool->slow));
@@ -234,10 +237,25 @@ static int page_pool_init(struct page_pool *pool,
/* Driver calling page_pool_create() also call page_pool_destroy() */
refcount_set(&pool->user_cnt, 1);
+ if (pool->mp_ops) {
+ err = pool->mp_ops->init(pool);
+ if (err) {
+ pr_warn("%s() mem-provider init failed %d\n",
+ __func__, err);
+ goto free_ptr_ring;
+ }
+
+ static_branch_inc(&page_pool_mem_providers);
+ }
+
if (pool->p.flags & PP_FLAG_DMA_MAP)
get_device(pool->p.dev);
return 0;
+
+free_ptr_ring:
+ ptr_ring_cleanup(&pool->ring, NULL);
+ return err;
}
static void page_pool_uninit(struct page_pool *pool)
@@ -519,7 +537,10 @@ struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
return page;
/* Slow-path: cache empty, do real allocation */
- page = __page_pool_alloc_pages_slow(pool, gfp);
+ if (static_branch_unlikely(&page_pool_mem_providers) && pool->mp_ops)
+ page = pool->mp_ops->alloc_pages(pool, gfp);
+ else
+ page = __page_pool_alloc_pages_slow(pool, gfp);
return page;
}
EXPORT_SYMBOL(page_pool_alloc_pages);
@@ -576,10 +597,13 @@ void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
void page_pool_return_page(struct page_pool *pool, struct page *page)
{
int count;
+ bool put;
- __page_pool_release_page_dma(pool, page);
-
- page_pool_clear_pp_info(page);
+ put = true;
+ if (static_branch_unlikely(&page_pool_mem_providers) && pool->mp_ops)
+ put = pool->mp_ops->release_page(pool, page);
+ else
+ __page_pool_release_page_dma(pool, page);
/* This may be the last page returned, releasing the pool, so
* it is not safe to reference pool afterwards.
@@ -587,7 +611,10 @@ void page_pool_return_page(struct page_pool *pool, struct page *page)
count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt);
trace_page_pool_state_release(pool, page, count);
- put_page(page);
+ if (put) {
+ page_pool_clear_pp_info(page);
+ put_page(page);
+ }
/* An optimization would be to call __free_pages(page, pool->p.order)
* knowing page is not part of page-cache (thus avoiding a
* __page_cache_release() call).
@@ -857,6 +884,12 @@ static void __page_pool_destroy(struct page_pool *pool)
page_pool_unlist(pool);
page_pool_uninit(pool);
+
+ if (pool->mp_ops) {
+ pool->mp_ops->destroy(pool);
+ static_branch_dec(&page_pool_mem_providers);
+ }
+
kfree(pool);
}
--
2.43.0.472.g3155946c3a-goog
The check is duplicated in 2 places, factor it out into a common helper.
Signed-off-by: Mina Almasry <[email protected]>
---
net/core/page_pool.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 45bb4210412d..0edb9251d98d 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -657,6 +657,11 @@ static bool page_pool_recycle_in_cache(struct page *page,
return true;
}
+static bool __page_pool_page_can_be_recycled(const struct page *page)
+{
+ return page_ref_count(page) == 1 && !page_is_pfmemalloc(page);
+}
+
/* If the page refcnt == 1, this will try to recycle the page.
* if PP_FLAG_DMA_SYNC_DEV is set, we'll try to sync the DMA area for
* the configured size min(dma_sync_size, pool->max_len).
@@ -678,7 +683,7 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
* page is NOT reusable when allocated when system is under
* some pressure. (page_is_pfmemalloc)
*/
- if (likely(page_ref_count(page) == 1 && !page_is_pfmemalloc(page))) {
+ if (likely(__page_pool_page_can_be_recycled(page))) {
/* Read barrier done in page_ref_count / READ_ONCE */
if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
@@ -793,7 +798,7 @@ static struct page *page_pool_drain_frag(struct page_pool *pool,
if (likely(page_pool_unref_page(page, drain_count)))
return NULL;
- if (page_ref_count(page) == 1 && !page_is_pfmemalloc(page)) {
+ if (__page_pool_page_can_be_recycled(page)) {
if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
page_pool_dma_sync_for_device(pool, page, -1);
--
2.43.0.472.g3155946c3a-goog
API takes the dma-buf fd as input, and binds it to the netdevice. The
user can specify the rx queues to bind the dma-buf to.
Suggested-by: Stanislav Fomichev <[email protected]>
Signed-off-by: Mina Almasry <[email protected]>
---
Changes in v1:
- Add rx-queue-type to distingish rx from tx (Jakub)
- Return dma-buf ID from netlink API (David, Stan)
Changes in RFC-v3:
- Support binding multiple rx rx-queues
---
Documentation/netlink/specs/netdev.yaml | 52 +++++++++++++++++++++++++
include/uapi/linux/netdev.h | 19 +++++++++
net/core/netdev-genl-gen.c | 19 +++++++++
net/core/netdev-genl-gen.h | 2 +
net/core/netdev-genl.c | 6 +++
tools/include/uapi/linux/netdev.h | 19 +++++++++
6 files changed, 117 insertions(+)
diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index f2c76d103bd8..df6a11d47006 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -260,6 +260,45 @@ attribute-sets:
name: napi-id
doc: ID of the NAPI instance which services this queue.
type: u32
+ -
+ name: queue-dmabuf
+ attributes:
+ -
+ name: type
+ doc: rx or tx queue
+ type: u8
+ enum: queue-type
+ -
+ name: idx
+ doc: queue index
+ type: u32
+
+ -
+ name: bind-dmabuf
+ attributes:
+ -
+ name: ifindex
+ doc: netdev ifindex to bind the dma-buf to.
+ type: u32
+ checks:
+ min: 1
+ -
+ name: queues
+ doc: receive queues to bind the dma-buf to.
+ type: nest
+ nested-attributes: queue-dmabuf
+ multi-attr: true
+ -
+ name: dmabuf-fd
+ doc: dmabuf file descriptor to bind.
+ type: u32
+ -
+ name: dmabuf-id
+ doc: id of the dmabuf binding
+ type: u32
+ checks:
+ min: 1
+
operations:
list:
@@ -382,6 +421,19 @@ operations:
attributes:
- ifindex
reply: *queue-get-op
+ -
+ name: bind-rx
+ doc: Bind dmabuf to netdev
+ attribute-set: bind-dmabuf
+ do:
+ request:
+ attributes:
+ - ifindex
+ - dmabuf-fd
+ - queues
+ reply:
+ attributes:
+ - dmabuf-id
-
name: napi-get
doc: Get information about NAPI instances configured on the system.
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 424c5e28f495..35d201dc4b05 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -129,6 +129,24 @@ enum {
NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
};
+enum {
+ NETDEV_A_QUEUE_DMABUF_TYPE = 1,
+ NETDEV_A_QUEUE_DMABUF_IDX,
+
+ __NETDEV_A_QUEUE_DMABUF_MAX,
+ NETDEV_A_QUEUE_DMABUF_MAX = (__NETDEV_A_QUEUE_DMABUF_MAX - 1)
+};
+
+enum {
+ NETDEV_A_BIND_DMABUF_IFINDEX = 1,
+ NETDEV_A_BIND_DMABUF_QUEUES,
+ NETDEV_A_BIND_DMABUF_DMABUF_FD,
+ NETDEV_A_BIND_DMABUF_DMABUF_ID,
+
+ __NETDEV_A_BIND_DMABUF_MAX,
+ NETDEV_A_BIND_DMABUF_MAX = (__NETDEV_A_BIND_DMABUF_MAX - 1)
+};
+
enum {
NETDEV_CMD_DEV_GET = 1,
NETDEV_CMD_DEV_ADD_NTF,
@@ -140,6 +158,7 @@ enum {
NETDEV_CMD_PAGE_POOL_CHANGE_NTF,
NETDEV_CMD_PAGE_POOL_STATS_GET,
NETDEV_CMD_QUEUE_GET,
+ NETDEV_CMD_BIND_RX,
NETDEV_CMD_NAPI_GET,
__NETDEV_CMD_MAX,
diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
index be7f2ebd61b2..3384b1ae3f40 100644
--- a/net/core/netdev-genl-gen.c
+++ b/net/core/netdev-genl-gen.c
@@ -27,6 +27,11 @@ const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFIND
[NETDEV_A_PAGE_POOL_IFINDEX] = NLA_POLICY_FULL_RANGE(NLA_U32, &netdev_a_page_pool_ifindex_range),
};
+const struct nla_policy netdev_queue_dmabuf_nl_policy[NETDEV_A_QUEUE_DMABUF_IDX + 1] = {
+ [NETDEV_A_QUEUE_DMABUF_TYPE] = NLA_POLICY_MAX(NLA_U8, 1),
+ [NETDEV_A_QUEUE_DMABUF_IDX] = { .type = NLA_U32, },
+};
+
/* NETDEV_CMD_DEV_GET - do */
static const struct nla_policy netdev_dev_get_nl_policy[NETDEV_A_DEV_IFINDEX + 1] = {
[NETDEV_A_DEV_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
@@ -58,6 +63,13 @@ static const struct nla_policy netdev_queue_get_dump_nl_policy[NETDEV_A_QUEUE_IF
[NETDEV_A_QUEUE_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
};
+/* NETDEV_CMD_BIND_RX - do */
+static const struct nla_policy netdev_bind_rx_nl_policy[NETDEV_A_BIND_DMABUF_DMABUF_FD + 1] = {
+ [NETDEV_A_BIND_DMABUF_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
+ [NETDEV_A_BIND_DMABUF_DMABUF_FD] = { .type = NLA_U32, },
+ [NETDEV_A_BIND_DMABUF_QUEUES] = NLA_POLICY_NESTED(netdev_queue_dmabuf_nl_policy),
+};
+
/* NETDEV_CMD_NAPI_GET - do */
static const struct nla_policy netdev_napi_get_do_nl_policy[NETDEV_A_NAPI_ID + 1] = {
[NETDEV_A_NAPI_ID] = { .type = NLA_U32, },
@@ -124,6 +136,13 @@ static const struct genl_split_ops netdev_nl_ops[] = {
.maxattr = NETDEV_A_QUEUE_IFINDEX,
.flags = GENL_CMD_CAP_DUMP,
},
+ {
+ .cmd = NETDEV_CMD_BIND_RX,
+ .doit = netdev_nl_bind_rx_doit,
+ .policy = netdev_bind_rx_nl_policy,
+ .maxattr = NETDEV_A_BIND_DMABUF_DMABUF_FD,
+ .flags = GENL_CMD_CAP_DO,
+ },
{
.cmd = NETDEV_CMD_NAPI_GET,
.doit = netdev_nl_napi_get_doit,
diff --git a/net/core/netdev-genl-gen.h b/net/core/netdev-genl-gen.h
index a47f2bcbe4fa..a7ede514eccd 100644
--- a/net/core/netdev-genl-gen.h
+++ b/net/core/netdev-genl-gen.h
@@ -13,6 +13,7 @@
/* Common nested types */
extern const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFINDEX + 1];
+extern const struct nla_policy netdev_queue_dmabuf_nl_policy[NETDEV_A_QUEUE_DMABUF_IDX + 1];
int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info);
int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
@@ -26,6 +27,7 @@ int netdev_nl_page_pool_stats_get_dumpit(struct sk_buff *skb,
int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info);
int netdev_nl_queue_get_dumpit(struct sk_buff *skb,
struct netlink_callback *cb);
+int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info);
int netdev_nl_napi_get_doit(struct sk_buff *skb, struct genl_info *info);
int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index fd98936da3ae..0ed292d87ae0 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -469,6 +469,12 @@ int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
return skb->len;
}
+/* Stub */
+int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info)
+{
+ return 0;
+}
+
static int netdev_genl_netdevice_event(struct notifier_block *nb,
unsigned long event, void *ptr)
{
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 424c5e28f495..35d201dc4b05 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -129,6 +129,24 @@ enum {
NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
};
+enum {
+ NETDEV_A_QUEUE_DMABUF_TYPE = 1,
+ NETDEV_A_QUEUE_DMABUF_IDX,
+
+ __NETDEV_A_QUEUE_DMABUF_MAX,
+ NETDEV_A_QUEUE_DMABUF_MAX = (__NETDEV_A_QUEUE_DMABUF_MAX - 1)
+};
+
+enum {
+ NETDEV_A_BIND_DMABUF_IFINDEX = 1,
+ NETDEV_A_BIND_DMABUF_QUEUES,
+ NETDEV_A_BIND_DMABUF_DMABUF_FD,
+ NETDEV_A_BIND_DMABUF_DMABUF_ID,
+
+ __NETDEV_A_BIND_DMABUF_MAX,
+ NETDEV_A_BIND_DMABUF_MAX = (__NETDEV_A_BIND_DMABUF_MAX - 1)
+};
+
enum {
NETDEV_CMD_DEV_GET = 1,
NETDEV_CMD_DEV_ADD_NTF,
@@ -140,6 +158,7 @@ enum {
NETDEV_CMD_PAGE_POOL_CHANGE_NTF,
NETDEV_CMD_PAGE_POOL_STATS_GET,
NETDEV_CMD_QUEUE_GET,
+ NETDEV_CMD_BIND_RX,
NETDEV_CMD_NAPI_GET,
__NETDEV_CMD_MAX,
--
2.43.0.472.g3155946c3a-goog
Add a netdev_dmabuf_binding struct which represents the
dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to
rx queues on the netdevice. On the binding, the dma_buf_attach
& dma_buf_map_attachment will occur. The entries in the sg_table from
mapping will be inserted into a genpool to make it ready
for allocation.
The chunks in the genpool are owned by a dmabuf_chunk_owner struct which
holds the dma-buf offset of the base of the chunk and the dma_addr of
the chunk. Both are needed to use allocations that come from this chunk.
We create a new type that represents an allocation from the genpool:
net_iov. We setup the net_iov allocation size in the
genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally
allocated by the page pool and given to the drivers.
The user can unbind the dmabuf from the netdevice by closing the netlink
socket that established the binding. We do this so that the binding is
automatically unbound even if the userspace process crashes.
The binding and unbinding leaves an indicator in struct netdev_rx_queue
that the given queue is bound, but the binding doesn't take effect until
the driver actually reconfigures its queues, and re-initializes its page
pool.
The netdev_dmabuf_binding struct is refcounted, and releases its
resources only when all the refs are released.
Signed-off-by: Willem de Bruijn <[email protected]>
Signed-off-by: Kaiyuan Zhang <[email protected]>
Signed-off-by: Mina Almasry <[email protected]>
---
RFC v5:
- Renamed page_pool_iov to net_iov, and moved that support to devmem.h
or netmem.h.
v1:
- Introduce devmem.h instead of bloating netdevice.h (Jakub)
- ENOTSUPP -> EOPNOTSUPP (checkpatch.pl I think)
- Remove unneeded rcu protection for binding->list (rtnl protected)
- Removed extraneous err_binding_put: label.
- Removed dma_addr += len (Paolo).
- Don't override err on netdev_bind_dmabuf_to_queue failure.
- Rename devmem -> dmabuf (David).
- Add id to dmabuf binding (David/Stan).
- Fix missing xa_destroy bound_rq_list.
- Use queue api to reset bound RX queues (Jakub).
- Update netlink API for rx-queue type (tx/re) (Jakub).
RFC v3:
- Support multi rx-queue binding
netmem support
---
include/net/devmem.h | 115 ++++++++++++++
include/net/netdev_rx_queue.h | 1 +
include/net/netmem.h | 10 ++
net/core/dev.c | 273 ++++++++++++++++++++++++++++++++++
net/core/netdev-genl.c | 121 ++++++++++++++-
5 files changed, 518 insertions(+), 2 deletions(-)
create mode 100644 include/net/devmem.h
diff --git a/include/net/devmem.h b/include/net/devmem.h
new file mode 100644
index 000000000000..85ccbbe84c65
--- /dev/null
+++ b/include/net/devmem.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Device memory TCP support
+ *
+ * Authors: Mina Almasry <[email protected]>
+ * Willem de Bruijn <[email protected]>
+ * Kaiyuan Zhang <[email protected]>
+ *
+ */
+#ifndef _NET_DEVMEM_H
+#define _NET_DEVMEM_H
+
+struct netdev_dmabuf_binding {
+ struct dma_buf *dmabuf;
+ struct dma_buf_attachment *attachment;
+ struct sg_table *sgt;
+ struct net_device *dev;
+ struct gen_pool *chunk_pool;
+
+ /* The user holds a ref (via the netlink API) for as long as they want
+ * the binding to remain alive. Each page pool using this binding holds
+ * a ref to keep the binding alive. Each allocated net_iov holds a
+ * ref.
+ *
+ * The binding undos itself and unmaps the underlying dmabuf once all
+ * those refs are dropped and the binding is no longer desired or in
+ * use.
+ */
+ refcount_t ref;
+
+ /* The portid of the user that owns this binding. Used for netlink to
+ * notify us of the user dropping the bind.
+ */
+ u32 owner_nlportid;
+
+ /* The list of bindings currently active. Used for netlink to notify us
+ * of the user dropping the bind.
+ */
+ struct list_head list;
+
+ /* rxq's this binding is active on. */
+ struct xarray bound_rxq_list;
+
+ /* ID of this binding. Globally unique to all bindings currently
+ * active.
+ */
+ u32 id;
+};
+
+/* Owner of the dma-buf chunks inserted into the gen pool. Each scatterlist
+ * entry from the dmabuf is inserted into the genpool as a chunk, and needs
+ * this owner struct to keep track of some metadata necessary to create
+ * allocations from this chunk.
+ */
+struct dmabuf_genpool_chunk_owner {
+ /* Offset into the dma-buf where this chunk starts. */
+ unsigned long base_virtual;
+
+ /* dma_addr of the start of the chunk. */
+ dma_addr_t base_dma_addr;
+
+ /* Array of net_iovs for this chunk. */
+ struct net_iov *niovs;
+ size_t num_niovs;
+
+ struct netdev_dmabuf_binding *binding;
+};
+
+#ifdef CONFIG_DMA_SHARED_BUFFER
+void __netdev_dmabuf_binding_free(struct netdev_dmabuf_binding *binding);
+int netdev_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd,
+ struct netdev_dmabuf_binding **out);
+void netdev_unbind_dmabuf(struct netdev_dmabuf_binding *binding);
+int netdev_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
+ struct netdev_dmabuf_binding *binding);
+#else
+static inline void
+__netdev_dmabuf_binding_free(struct netdev_dmabuf_binding *binding)
+{
+}
+
+static inline int netdev_bind_dmabuf(struct net_device *dev,
+ unsigned int dmabuf_fd,
+ struct netdev_dmabuf_binding **out)
+{
+ return -EOPNOTSUPP;
+}
+static inline void netdev_unbind_dmabuf(struct netdev_dmabuf_binding *binding)
+{
+}
+
+static inline int
+netdev_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
+ struct netdev_dmabuf_binding *binding)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
+static inline void
+netdev_dmabuf_binding_get(struct netdev_dmabuf_binding *binding)
+{
+ refcount_inc(&binding->ref);
+}
+
+static inline void
+netdev_dmabuf_binding_put(struct netdev_dmabuf_binding *binding)
+{
+ if (!refcount_dec_and_test(&binding->ref))
+ return;
+
+ __netdev_dmabuf_binding_free(binding);
+}
+
+#endif /* _NET_DEVMEM_H */
diff --git a/include/net/netdev_rx_queue.h b/include/net/netdev_rx_queue.h
index aa1716fb0e53..5dc35628633a 100644
--- a/include/net/netdev_rx_queue.h
+++ b/include/net/netdev_rx_queue.h
@@ -25,6 +25,7 @@ struct netdev_rx_queue {
* Readers and writers must hold RTNL
*/
struct napi_struct *napi;
+ struct netdev_dmabuf_binding *binding;
} ____cacheline_aligned_in_smp;
/*
diff --git a/include/net/netmem.h b/include/net/netmem.h
index b60b00216704..45eb42d9990b 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -8,6 +8,16 @@
#ifndef _NET_NETMEM_H
#define _NET_NETMEM_H
+#include <net/devmem.h>
+
+/* net_iov */
+
+struct net_iov {
+ struct dmabuf_genpool_chunk_owner *owner;
+};
+
+/* netmem */
+
struct netmem {
union {
struct page page;
diff --git a/net/core/dev.c b/net/core/dev.c
index 0432b04cf9b0..2e474099267a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -153,6 +153,9 @@
#include <linux/prandom.h>
#include <linux/once_lite.h>
#include <net/netdev_rx_queue.h>
+#include <linux/genalloc.h>
+#include <linux/dma-buf.h>
+#include <net/devmem.h>
#include "dev.h"
#include "net-sysfs.h"
@@ -2041,6 +2044,276 @@ static int call_netdevice_notifiers_mtu(unsigned long val,
return call_netdevice_notifiers_info(val, &info.info);
}
+/* Device memory support */
+
+#ifdef CONFIG_DMA_SHARED_BUFFER
+static void netdev_dmabuf_free_chunk_owner(struct gen_pool *genpool,
+ struct gen_pool_chunk *chunk,
+ void *not_used)
+{
+ struct dmabuf_genpool_chunk_owner *owner = chunk->owner;
+
+ kvfree(owner->niovs);
+ kfree(owner);
+}
+
+void __netdev_dmabuf_binding_free(struct netdev_dmabuf_binding *binding)
+{
+ size_t size, avail;
+
+ gen_pool_for_each_chunk(binding->chunk_pool,
+ netdev_dmabuf_free_chunk_owner, NULL);
+
+ size = gen_pool_size(binding->chunk_pool);
+ avail = gen_pool_avail(binding->chunk_pool);
+
+ if (!WARN(size != avail, "can't destroy genpool. size=%lu, avail=%lu",
+ size, avail))
+ gen_pool_destroy(binding->chunk_pool);
+
+ dma_buf_unmap_attachment(binding->attachment, binding->sgt,
+ DMA_BIDIRECTIONAL);
+ dma_buf_detach(binding->dmabuf, binding->attachment);
+ dma_buf_put(binding->dmabuf);
+ xa_destroy(&binding->bound_rxq_list);
+ kfree(binding);
+}
+
+static int netdev_restart_rx_queue(struct net_device *dev, int rxq_idx)
+{
+ void *new_mem;
+ void *old_mem;
+ int err;
+
+ if (!dev || !dev->netdev_ops)
+ return -EINVAL;
+
+ if (!dev->netdev_ops->ndo_queue_stop ||
+ !dev->netdev_ops->ndo_queue_mem_free ||
+ !dev->netdev_ops->ndo_queue_mem_alloc ||
+ !dev->netdev_ops->ndo_queue_start)
+ return -EOPNOTSUPP;
+
+ new_mem = dev->netdev_ops->ndo_queue_mem_alloc(dev, rxq_idx);
+ if (!new_mem)
+ return -ENOMEM;
+
+ err = dev->netdev_ops->ndo_queue_stop(dev, rxq_idx, &old_mem);
+ if (err)
+ goto err_free_new_mem;
+
+ err = dev->netdev_ops->ndo_queue_start(dev, rxq_idx, new_mem);
+ if (err)
+ goto err_start_queue;
+
+ dev->netdev_ops->ndo_queue_mem_free(dev, old_mem);
+
+ return 0;
+
+err_start_queue:
+ dev->netdev_ops->ndo_queue_start(dev, rxq_idx, old_mem);
+
+err_free_new_mem:
+ dev->netdev_ops->ndo_queue_mem_free(dev, new_mem);
+
+ return err;
+}
+
+/* Protected by rtnl_lock() */
+static DEFINE_XARRAY_FLAGS(netdev_dmabuf_bindings, XA_FLAGS_ALLOC1);
+
+void netdev_unbind_dmabuf(struct netdev_dmabuf_binding *binding)
+{
+ struct netdev_rx_queue *rxq;
+ unsigned long xa_idx;
+ unsigned int rxq_idx;
+
+ if (!binding)
+ return;
+
+ if (binding->list.next)
+ list_del(&binding->list);
+
+ xa_for_each(&binding->bound_rxq_list, xa_idx, rxq) {
+ if (rxq->binding == binding) {
+ /* We hold the rtnl_lock while binding/unbinding
+ * dma-buf, so we can't race with another thread that
+ * is also modifying this value. However, the driver
+ * may read this config while it's creating its
+ * rx-queues. WRITE_ONCE() here to match the
+ * READ_ONCE() in the driver.
+ */
+ WRITE_ONCE(rxq->binding, NULL);
+
+ rxq_idx = get_netdev_rx_queue_index(rxq);
+
+ netdev_restart_rx_queue(binding->dev, rxq_idx);
+ }
+ }
+
+ xa_erase(&netdev_dmabuf_bindings, binding->id);
+
+ netdev_dmabuf_binding_put(binding);
+}
+
+int netdev_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
+ struct netdev_dmabuf_binding *binding)
+{
+ struct netdev_rx_queue *rxq;
+ u32 xa_idx;
+ int err;
+
+ rxq = __netif_get_rx_queue(dev, rxq_idx);
+
+ if (rxq->binding)
+ return -EEXIST;
+
+ err = xa_alloc(&binding->bound_rxq_list, &xa_idx, rxq, xa_limit_32b,
+ GFP_KERNEL);
+ if (err)
+ return err;
+
+ /* We hold the rtnl_lock while binding/unbinding dma-buf, so we can't
+ * race with another thread that is also modifying this value. However,
+ * the driver may read this config while it's creating its * rx-queues.
+ * WRITE_ONCE() here to match the READ_ONCE() in the driver.
+ */
+ WRITE_ONCE(rxq->binding, binding);
+
+ err = netdev_restart_rx_queue(dev, rxq_idx);
+ if (err)
+ goto err_xa_erase;
+
+ return 0;
+
+err_xa_erase:
+ xa_erase(&binding->bound_rxq_list, xa_idx);
+ WRITE_ONCE(rxq->binding, NULL);
+
+ return err;
+}
+
+int netdev_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd,
+ struct netdev_dmabuf_binding **out)
+{
+ struct netdev_dmabuf_binding *binding;
+ static u32 id_alloc_next;
+ struct scatterlist *sg;
+ struct dma_buf *dmabuf;
+ unsigned int sg_idx, i;
+ unsigned long virtual;
+ int err;
+
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ dmabuf = dma_buf_get(dmabuf_fd);
+ if (IS_ERR_OR_NULL(dmabuf))
+ return -EBADFD;
+
+ binding = kzalloc_node(sizeof(*binding), GFP_KERNEL,
+ dev_to_node(&dev->dev));
+ if (!binding) {
+ err = -ENOMEM;
+ goto err_put_dmabuf;
+ }
+ binding->dev = dev;
+
+ err = xa_alloc_cyclic(&netdev_dmabuf_bindings, &binding->id, binding,
+ xa_limit_32b, &id_alloc_next, GFP_KERNEL);
+ if (err < 0)
+ goto err_free_binding;
+
+ xa_init_flags(&binding->bound_rxq_list, XA_FLAGS_ALLOC);
+
+ refcount_set(&binding->ref, 1);
+
+ binding->dmabuf = dmabuf;
+
+ binding->attachment = dma_buf_attach(binding->dmabuf, dev->dev.parent);
+ if (IS_ERR(binding->attachment)) {
+ err = PTR_ERR(binding->attachment);
+ goto err_free_id;
+ }
+
+ binding->sgt =
+ dma_buf_map_attachment(binding->attachment, DMA_BIDIRECTIONAL);
+ if (IS_ERR(binding->sgt)) {
+ err = PTR_ERR(binding->sgt);
+ goto err_detach;
+ }
+
+ /* For simplicity we expect to make PAGE_SIZE allocations, but the
+ * binding can be much more flexible than that. We may be able to
+ * allocate MTU sized chunks here. Leave that for future work...
+ */
+ binding->chunk_pool =
+ gen_pool_create(PAGE_SHIFT, dev_to_node(&dev->dev));
+ if (!binding->chunk_pool) {
+ err = -ENOMEM;
+ goto err_unmap;
+ }
+
+ virtual = 0;
+ for_each_sgtable_dma_sg(binding->sgt, sg, sg_idx) {
+ dma_addr_t dma_addr = sg_dma_address(sg);
+ struct dmabuf_genpool_chunk_owner *owner;
+ size_t len = sg_dma_len(sg);
+ struct net_iov *niov;
+
+ owner = kzalloc_node(sizeof(*owner), GFP_KERNEL,
+ dev_to_node(&dev->dev));
+ owner->base_virtual = virtual;
+ owner->base_dma_addr = dma_addr;
+ owner->num_niovs = len / PAGE_SIZE;
+ owner->binding = binding;
+
+ err = gen_pool_add_owner(binding->chunk_pool, dma_addr,
+ dma_addr, len, dev_to_node(&dev->dev),
+ owner);
+ if (err) {
+ err = -EINVAL;
+ goto err_free_chunks;
+ }
+
+ owner->niovs = kvmalloc_array(
+ owner->num_niovs, sizeof(*owner->niovs), GFP_KERNEL);
+ if (!owner->niovs) {
+ err = -ENOMEM;
+ goto err_free_chunks;
+ }
+
+ for (i = 0; i < owner->num_niovs; i++) {
+ niov = &owner->niovs[i];
+ niov->owner = owner;
+ }
+
+ virtual += len;
+ }
+
+ *out = binding;
+
+ return 0;
+
+err_free_chunks:
+ gen_pool_for_each_chunk(binding->chunk_pool,
+ netdev_dmabuf_free_chunk_owner, NULL);
+ gen_pool_destroy(binding->chunk_pool);
+err_unmap:
+ dma_buf_unmap_attachment(binding->attachment, binding->sgt,
+ DMA_BIDIRECTIONAL);
+err_detach:
+ dma_buf_detach(dmabuf, binding->attachment);
+err_free_id:
+ xa_erase(&netdev_dmabuf_bindings, binding->id);
+err_free_binding:
+ kfree(binding);
+err_put_dmabuf:
+ dma_buf_put(dmabuf);
+ return err;
+}
+#endif
+
#ifdef CONFIG_NET_INGRESS
static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 0ed292d87ae0..8f0867ae5eeb 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -9,6 +9,7 @@
#include <net/xdp_sock.h>
#include <net/netdev_rx_queue.h>
#include <net/busy_poll.h>
+#include <net/devmem.h>
#include "netdev-genl-gen.h"
#include "dev.h"
@@ -469,10 +470,93 @@ int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
return skb->len;
}
-/* Stub */
+static LIST_HEAD(netdev_rbinding_list);
+
int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info)
{
- return 0;
+ struct nlattr *tb[ARRAY_SIZE(netdev_queue_dmabuf_nl_policy)];
+ struct netdev_dmabuf_binding *out_binding;
+ u32 ifindex, dmabuf_fd, rxq_idx;
+ struct net_device *netdev;
+ struct sk_buff *rsp;
+ struct nlattr *attr;
+ int rem, err = 0;
+ void *hdr;
+
+ if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_DEV_IFINDEX) ||
+ GENL_REQ_ATTR_CHECK(info, NETDEV_A_BIND_DMABUF_DMABUF_FD) ||
+ GENL_REQ_ATTR_CHECK(info, NETDEV_A_BIND_DMABUF_QUEUES))
+ return -EINVAL;
+
+ ifindex = nla_get_u32(info->attrs[NETDEV_A_DEV_IFINDEX]);
+ dmabuf_fd = nla_get_u32(info->attrs[NETDEV_A_BIND_DMABUF_DMABUF_FD]);
+
+ rtnl_lock();
+
+ netdev = __dev_get_by_index(genl_info_net(info), ifindex);
+ if (!netdev) {
+ err = -ENODEV;
+ goto err_unlock;
+ }
+
+ err = netdev_bind_dmabuf(netdev, dmabuf_fd, &out_binding);
+ if (err)
+ goto err_unlock;
+
+ nla_for_each_attr(attr, genlmsg_data(info->genlhdr),
+ genlmsg_len(info->genlhdr), rem) {
+ if (nla_type(attr) != NETDEV_A_BIND_DMABUF_QUEUES)
+ continue;
+
+ err = nla_parse_nested(
+ tb, ARRAY_SIZE(netdev_queue_dmabuf_nl_policy) - 1, attr,
+ netdev_queue_dmabuf_nl_policy, info->extack);
+
+ if (err < 0)
+ goto err_unbind;
+
+ rxq_idx = nla_get_u32(tb[NETDEV_A_QUEUE_DMABUF_IDX]);
+
+ if (rxq_idx >= netdev->num_rx_queues) {
+ err = -ERANGE;
+ goto err_unbind;
+ }
+
+ err = netdev_bind_dmabuf_to_queue(netdev, rxq_idx, out_binding);
+ if (err)
+ goto err_unbind;
+ }
+
+ out_binding->owner_nlportid = info->snd_portid;
+ list_add(&out_binding->list, &netdev_rbinding_list);
+
+ rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!rsp) {
+ err = -ENOMEM;
+ goto err_unbind;
+ }
+
+ hdr = genlmsg_put(rsp, info->snd_portid, info->snd_seq,
+ &netdev_nl_family, 0, info->genlhdr->cmd);
+ if (!hdr) {
+ err = -EMSGSIZE;
+ goto err_genlmsg_free;
+ }
+
+ nla_put_u32(rsp, NETDEV_A_BIND_DMABUF_DMABUF_ID, out_binding->id);
+ genlmsg_end(rsp, hdr);
+
+ rtnl_unlock();
+
+ return genlmsg_reply(rsp, info);
+
+err_genlmsg_free:
+ nlmsg_free(rsp);
+err_unbind:
+ netdev_unbind_dmabuf(out_binding);
+err_unlock:
+ rtnl_unlock();
+ return err;
}
static int netdev_genl_netdevice_event(struct notifier_block *nb,
@@ -495,10 +579,37 @@ static int netdev_genl_netdevice_event(struct notifier_block *nb,
return NOTIFY_OK;
}
+static int netdev_netlink_notify(struct notifier_block *nb, unsigned long state,
+ void *_notify)
+{
+ struct netlink_notify *notify = _notify;
+ struct netdev_dmabuf_binding *rbinding;
+
+ if (state != NETLINK_URELEASE || notify->protocol != NETLINK_GENERIC)
+ return NOTIFY_DONE;
+
+ rtnl_lock();
+
+ list_for_each_entry(rbinding, &netdev_rbinding_list, list) {
+ if (rbinding->owner_nlportid == notify->portid) {
+ netdev_unbind_dmabuf(rbinding);
+ break;
+ }
+ }
+
+ rtnl_unlock();
+
+ return NOTIFY_OK;
+}
+
static struct notifier_block netdev_genl_nb = {
.notifier_call = netdev_genl_netdevice_event,
};
+static struct notifier_block netdev_netlink_notifier = {
+ .notifier_call = netdev_netlink_notify,
+};
+
static int __init netdev_genl_init(void)
{
int err;
@@ -511,8 +622,14 @@ static int __init netdev_genl_init(void)
if (err)
goto err_unreg_ntf;
+ err = netlink_register_notifier(&netdev_netlink_notifier);
+ if (err)
+ goto err_unreg_family;
+
return 0;
+err_unreg_family:
+ genl_unregister_family(&netdev_nl_family);
err_unreg_ntf:
unregister_netdevice_notifier(&netdev_genl_nb);
return err;
--
2.43.0.472.g3155946c3a-goog
Implement netdev devmem allocator. The allocator takes a given struct
netdev_dmabuf_binding as input and allocates net_iov from that
binding.
The allocation simply delegates to the binding's genpool for the
allocation logic and wraps the returned memory region in a net_iov
struct.
Signed-off-by: Willem de Bruijn <[email protected]>
Signed-off-by: Kaiyuan Zhang <[email protected]>
Signed-off-by: Mina Almasry <[email protected]>
---
v1:
- Rename devmem -> dmabuf (David).
---
include/net/devmem.h | 12 ++++++++++++
include/net/netmem.h | 26 ++++++++++++++++++++++++++
net/core/dev.c | 38 ++++++++++++++++++++++++++++++++++++++
3 files changed, 76 insertions(+)
diff --git a/include/net/devmem.h b/include/net/devmem.h
index 85ccbbe84c65..4207adadc2bb 100644
--- a/include/net/devmem.h
+++ b/include/net/devmem.h
@@ -67,6 +67,8 @@ struct dmabuf_genpool_chunk_owner {
};
#ifdef CONFIG_DMA_SHARED_BUFFER
+struct net_iov *netdev_alloc_dmabuf(struct netdev_dmabuf_binding *binding);
+void netdev_free_dmabuf(struct net_iov *ppiov);
void __netdev_dmabuf_binding_free(struct netdev_dmabuf_binding *binding);
int netdev_bind_dmabuf(struct net_device *dev, unsigned int dmabuf_fd,
struct netdev_dmabuf_binding **out);
@@ -74,6 +76,16 @@ void netdev_unbind_dmabuf(struct netdev_dmabuf_binding *binding);
int netdev_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
struct netdev_dmabuf_binding *binding);
#else
+static inline struct net_iov *
+netdev_alloc_dmabuf(struct netdev_dmabuf_binding *binding)
+{
+ return NULL;
+}
+
+static inline void netdev_free_dmabuf(struct net_iov *ppiov)
+{
+}
+
static inline void
__netdev_dmabuf_binding_free(struct netdev_dmabuf_binding *binding)
{
diff --git a/include/net/netmem.h b/include/net/netmem.h
index 45eb42d9990b..7fce2efc8707 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -14,8 +14,34 @@
struct net_iov {
struct dmabuf_genpool_chunk_owner *owner;
+ unsigned long dma_addr;
};
+static inline struct dmabuf_genpool_chunk_owner *
+net_iov_owner(const struct net_iov *niov)
+{
+ return niov->owner;
+}
+
+static inline unsigned int net_iov_idx(const struct net_iov *niov)
+{
+ return niov - net_iov_owner(niov)->niovs;
+}
+
+static inline dma_addr_t net_iov_dma_addr(const struct net_iov *niov)
+{
+ struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov);
+
+ return owner->base_dma_addr +
+ ((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT);
+}
+
+static inline struct netdev_dmabuf_binding *
+net_iov_binding(const struct net_iov *niov)
+{
+ return net_iov_owner(niov)->binding;
+}
+
/* netmem */
struct netmem {
diff --git a/net/core/dev.c b/net/core/dev.c
index 2e474099267a..20ba528ef426 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2119,6 +2119,44 @@ static int netdev_restart_rx_queue(struct net_device *dev, int rxq_idx)
return err;
}
+struct net_iov *netdev_alloc_dmabuf(struct netdev_dmabuf_binding *binding)
+{
+ struct dmabuf_genpool_chunk_owner *owner;
+ unsigned long dma_addr;
+ struct net_iov *niov;
+ ssize_t offset;
+ ssize_t index;
+
+ dma_addr = gen_pool_alloc_owner(binding->chunk_pool, PAGE_SIZE,
+ (void **)&owner);
+ if (!dma_addr)
+ return NULL;
+
+ offset = dma_addr - owner->base_dma_addr;
+ index = offset / PAGE_SIZE;
+ niov = &owner->niovs[index];
+
+ niov->pp_magic = 0;
+ niov->pp = NULL;
+ niov->dma_addr = 0;
+ atomic_long_set(&niov->pp_ref_count, 0);
+
+ netdev_dmabuf_binding_get(binding);
+
+ return niov;
+}
+
+void netdev_free_dmabuf(struct net_iov *niov)
+{
+ struct netdev_dmabuf_binding *binding = net_iov_binding(niov);
+ unsigned long dma_addr = net_iov_dma_addr(niov);
+
+ if (gen_pool_has_addr(binding->chunk_pool, dma_addr, PAGE_SIZE))
+ gen_pool_free(binding->chunk_pool, dma_addr, PAGE_SIZE);
+
+ netdev_dmabuf_binding_put(binding);
+}
+
/* Protected by rtnl_lock() */
static DEFINE_XARRAY_FLAGS(netdev_dmabuf_bindings, XA_FLAGS_ALLOC1);
--
2.43.0.472.g3155946c3a-goog
Abstrace the memory type from the page_pool so we can later add support
for new memory types. Convert the page_pool to use the new netmem type
abstraction, rather than use struct page directly.
As of this patch the netmem type is a no-op abstraction: it's always a
struct page underneath. All the page pool internals are converted to
use struct netmem instead of struct page, and the page pool now exports
2 APIs:
1. The existing struct page API.
2. The new struct netmem API.
Keeping the existing API is transitional; we do not want to refactor all
the curent drivers using the page pool at once.
The netmem abstraction is currently a no-op. The page_pool uses
page_to_netmem() to convert allocated pages to netmem, and uses
netmem_to_page() to convert the netmem back to pages to pass to mm APIs,
Follow up patches to this series add non-paged netmem support to the
page_pool. This change is factored out on its own to limit the code
churn to this 1 patch, for ease of code review.
Signed-off-by: Mina Almasry <[email protected]>
---
include/linux/skbuff.h | 4 +-
include/net/netmem.h | 15 ++
include/net/page_pool/helpers.h | 106 ++++++++----
include/net/page_pool/types.h | 17 +-
include/trace/events/page_pool.h | 28 +--
net/bpf/test_run.c | 5 +-
net/core/page_pool.c | 286 +++++++++++++++++--------------
net/core/skbuff.c | 7 +-
8 files changed, 285 insertions(+), 183 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 03ab13072962..1189d8d22da8 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3486,7 +3486,7 @@ static inline void skb_frag_ref(struct sk_buff *skb, int f)
__skb_frag_ref(&skb_shinfo(skb)->frags[f]);
}
-bool napi_pp_put_page(struct page *page, bool napi_safe);
+bool napi_pp_put_page(struct netmem *netmem, bool napi_safe);
static inline void
napi_frag_unref(skb_frag_t *frag, bool recycle, bool napi_safe)
@@ -3494,7 +3494,7 @@ napi_frag_unref(skb_frag_t *frag, bool recycle, bool napi_safe)
struct page *page = skb_frag_page(frag);
#ifdef CONFIG_PAGE_POOL
- if (recycle && napi_pp_put_page(page, napi_safe))
+ if (recycle && napi_pp_put_page(page_to_netmem(page), napi_safe))
return;
#endif
put_page(page);
diff --git a/include/net/netmem.h b/include/net/netmem.h
index 7fce2efc8707..31f338f19da0 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -68,4 +68,19 @@ static inline struct netmem *page_to_netmem(struct page *page)
return container_of(page, struct netmem, page);
}
+static inline int netmem_ref_count(struct netmem *netmem)
+{
+ return page_ref_count(netmem_to_page(netmem));
+}
+
+static inline unsigned long netmem_to_pfn(struct netmem *netmem)
+{
+ return page_to_pfn(netmem_to_page(netmem));
+}
+
+static inline struct netmem *netmem_compound_head(struct netmem *netmem)
+{
+ return page_to_netmem(compound_head(netmem_to_page(netmem)));
+}
+
#endif /* _NET_NETMEM_H */
diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
index ead2c0d24b2c..c71969279284 100644
--- a/include/net/page_pool/helpers.h
+++ b/include/net/page_pool/helpers.h
@@ -53,6 +53,8 @@
#define _NET_PAGE_POOL_HELPERS_H
#include <net/page_pool/types.h>
+#include <net/net_debug.h>
+#include <net/netmem.h>
#ifdef CONFIG_PAGE_POOL_STATS
/* Deprecated driver-facing API, use netlink instead */
@@ -112,21 +114,21 @@ static inline struct page *page_pool_dev_alloc_frag(struct page_pool *pool,
return page_pool_alloc_frag(pool, offset, size, gfp);
}
-static inline struct page *page_pool_alloc(struct page_pool *pool,
- unsigned int *offset,
- unsigned int *size, gfp_t gfp)
+static inline struct netmem *page_pool_alloc(struct page_pool *pool,
+ unsigned int *offset,
+ unsigned int *size, gfp_t gfp)
{
unsigned int max_size = PAGE_SIZE << pool->p.order;
- struct page *page;
+ struct netmem *netmem;
if ((*size << 1) > max_size) {
*size = max_size;
*offset = 0;
- return page_pool_alloc_pages(pool, gfp);
+ return page_pool_alloc_netmem(pool, gfp);
}
- page = page_pool_alloc_frag(pool, offset, *size, gfp);
- if (unlikely(!page))
+ netmem = page_pool_alloc_frag_netmem(pool, offset, *size, gfp);
+ if (unlikely(!netmem))
return NULL;
/* There is very likely not enough space for another fragment, so append
@@ -138,7 +140,7 @@ static inline struct page *page_pool_alloc(struct page_pool *pool,
pool->frag_offset = max_size;
}
- return page;
+ return netmem;
}
/**
@@ -160,7 +162,7 @@ static inline struct page *page_pool_dev_alloc(struct page_pool *pool,
{
gfp_t gfp = (GFP_ATOMIC | __GFP_NOWARN);
- return page_pool_alloc(pool, offset, size, gfp);
+ return netmem_to_page(page_pool_alloc(pool, offset, size, gfp));
}
static inline void *page_pool_alloc_va(struct page_pool *pool,
@@ -170,7 +172,8 @@ static inline void *page_pool_alloc_va(struct page_pool *pool,
struct page *page;
/* Mask off __GFP_HIGHMEM to ensure we can use page_address() */
- page = page_pool_alloc(pool, &offset, size, gfp & ~__GFP_HIGHMEM);
+ page = netmem_to_page(
+ page_pool_alloc(pool, &offset, size, gfp & ~__GFP_HIGHMEM));
if (unlikely(!page))
return NULL;
@@ -210,6 +213,11 @@ inline enum dma_data_direction page_pool_get_dma_dir(struct page_pool *pool)
return pool->p.dma_dir;
}
+static inline void page_pool_fragment_netmem(struct netmem *netmem, long nr)
+{
+ atomic_long_set(&netmem_to_page(netmem)->pp_ref_count, nr);
+}
+
/**
* page_pool_fragment_page() - split a fresh page into fragments
* @page: page to split
@@ -230,11 +238,12 @@ inline enum dma_data_direction page_pool_get_dma_dir(struct page_pool *pool)
*/
static inline void page_pool_fragment_page(struct page *page, long nr)
{
- atomic_long_set(&page->pp_ref_count, nr);
+ page_pool_fragment_netmem(page_to_netmem(page), nr);
}
-static inline long page_pool_unref_page(struct page *page, long nr)
+static inline long page_pool_unref_netmem(struct netmem *netmem, long nr)
{
+ struct page *page = netmem_to_page(netmem);
long ret;
/* If nr == pp_ref_count then we have cleared all remaining
@@ -277,10 +286,32 @@ static inline long page_pool_unref_page(struct page *page, long nr)
return ret;
}
-static inline bool page_pool_is_last_ref(struct page *page)
+static inline long page_pool_unref_page(struct page *page, long nr)
+{
+ return page_pool_unref_netmem(page_to_netmem(page), nr);
+}
+
+static inline bool page_pool_is_last_ref(struct netmem *netmem)
{
/* If page_pool_unref_page() returns 0, we were the last user */
- return page_pool_unref_page(page, 1) == 0;
+ return page_pool_unref_netmem(netmem, 1) == 0;
+}
+
+static inline void page_pool_put_netmem(struct page_pool *pool,
+ struct netmem *netmem,
+ unsigned int dma_sync_size,
+ bool allow_direct)
+{
+ /* When page_pool isn't compiled-in, net/core/xdp.c doesn't
+ * allow registering MEM_TYPE_PAGE_POOL, but shield linker.
+ */
+#ifdef CONFIG_PAGE_POOL
+ if (!page_pool_is_last_ref(netmem))
+ return;
+
+ page_pool_put_unrefed_netmem(pool, netmem, dma_sync_size,
+ allow_direct);
+#endif
}
/**
@@ -301,15 +332,15 @@ static inline void page_pool_put_page(struct page_pool *pool,
unsigned int dma_sync_size,
bool allow_direct)
{
- /* When page_pool isn't compiled-in, net/core/xdp.c doesn't
- * allow registering MEM_TYPE_PAGE_POOL, but shield linker.
- */
-#ifdef CONFIG_PAGE_POOL
- if (!page_pool_is_last_ref(page))
- return;
+ page_pool_put_netmem(pool, page_to_netmem(page), dma_sync_size,
+ allow_direct);
+}
- page_pool_put_unrefed_page(pool, page, dma_sync_size, allow_direct);
-#endif
+static inline void page_pool_put_full_netmem(struct page_pool *pool,
+ struct netmem *netmem,
+ bool allow_direct)
+{
+ page_pool_put_netmem(pool, netmem, -1, allow_direct);
}
/**
@@ -324,7 +355,7 @@ static inline void page_pool_put_page(struct page_pool *pool,
static inline void page_pool_put_full_page(struct page_pool *pool,
struct page *page, bool allow_direct)
{
- page_pool_put_page(pool, page, -1, allow_direct);
+ page_pool_put_netmem(pool, page_to_netmem(page), -1, allow_direct);
}
/**
@@ -358,6 +389,18 @@ static inline void page_pool_free_va(struct page_pool *pool, void *va,
page_pool_put_page(pool, virt_to_head_page(va), -1, allow_direct);
}
+static inline dma_addr_t page_pool_get_dma_addr_netmem(struct netmem *netmem)
+{
+ struct page *page = netmem_to_page(netmem);
+
+ dma_addr_t ret = page->dma_addr;
+
+ if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
+ ret <<= PAGE_SHIFT;
+
+ return ret;
+}
+
/**
* page_pool_get_dma_addr() - Retrieve the stored DMA address.
* @page: page allocated from a page pool
@@ -367,16 +410,14 @@ static inline void page_pool_free_va(struct page_pool *pool, void *va,
*/
static inline dma_addr_t page_pool_get_dma_addr(struct page *page)
{
- dma_addr_t ret = page->dma_addr;
-
- if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
- ret <<= PAGE_SHIFT;
-
- return ret;
+ return page_pool_get_dma_addr_netmem(page_to_netmem(page));
}
-static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
+static inline bool page_pool_set_dma_addr_netmem(struct netmem *netmem,
+ dma_addr_t addr)
{
+ struct page *page = netmem_to_page(netmem);
+
if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) {
page->dma_addr = addr >> PAGE_SHIFT;
@@ -390,6 +431,11 @@ static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
return false;
}
+static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
+{
+ return page_pool_set_dma_addr_netmem(page_to_netmem(page), addr);
+}
+
static inline bool page_pool_put(struct page_pool *pool)
{
return refcount_dec_and_test(&pool->user_cnt);
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 4c090e86e550..433ae9ae658b 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -39,7 +39,7 @@
#define PP_ALLOC_CACHE_REFILL 64
struct pp_alloc_cache {
u32 count;
- struct page *cache[PP_ALLOC_CACHE_SIZE];
+ struct netmem *cache[PP_ALLOC_CACHE_SIZE];
};
/**
@@ -72,7 +72,7 @@ struct page_pool_params {
struct_group_tagged(page_pool_params_slow, slow,
struct net_device *netdev;
/* private: used by test code only */
- void (*init_callback)(struct page *page, void *arg);
+ void (*init_callback)(struct netmem *netmem, void *arg);
void *init_arg;
);
};
@@ -130,8 +130,8 @@ struct page_pool_stats {
struct memory_provider_ops {
int (*init)(struct page_pool *pool);
void (*destroy)(struct page_pool *pool);
- struct page *(*alloc_pages)(struct page_pool *pool, gfp_t gfp);
- bool (*release_page)(struct page_pool *pool, struct page *page);
+ struct netmem *(*alloc_pages)(struct page_pool *pool, gfp_t gfp);
+ bool (*release_page)(struct page_pool *pool, struct netmem *netmem);
};
struct page_pool {
@@ -140,7 +140,7 @@ struct page_pool {
bool has_init_callback;
long frag_users;
- struct page *frag_page;
+ struct netmem *frag_page;
unsigned int frag_offset;
u32 pages_state_hold_cnt;
@@ -212,8 +212,12 @@ struct page_pool {
};
struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);
+struct netmem *page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp);
struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset,
unsigned int size, gfp_t gfp);
+struct netmem *page_pool_alloc_frag_netmem(struct page_pool *pool,
+ unsigned int *offset,
+ unsigned int size, gfp_t gfp);
struct page_pool *page_pool_create(const struct page_pool_params *params);
struct xdp_mem_info;
@@ -246,6 +250,9 @@ static inline void page_pool_put_page_bulk(struct page_pool *pool, void **data,
}
#endif
+void page_pool_put_unrefed_netmem(struct page_pool *pool, struct netmem *netmem,
+ unsigned int dma_sync_size,
+ bool allow_direct);
void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page,
unsigned int dma_sync_size,
bool allow_direct);
diff --git a/include/trace/events/page_pool.h b/include/trace/events/page_pool.h
index 6834356b2d2a..9574085568f3 100644
--- a/include/trace/events/page_pool.h
+++ b/include/trace/events/page_pool.h
@@ -42,51 +42,51 @@ TRACE_EVENT(page_pool_release,
TRACE_EVENT(page_pool_state_release,
TP_PROTO(const struct page_pool *pool,
- const struct page *page, u32 release),
+ struct netmem *netmem, u32 release),
- TP_ARGS(pool, page, release),
+ TP_ARGS(pool, netmem, release),
TP_STRUCT__entry(
__field(const struct page_pool *, pool)
- __field(const struct page *, page)
+ __field(struct netmem *, netmem)
__field(u32, release)
__field(unsigned long, pfn)
),
TP_fast_assign(
__entry->pool = pool;
- __entry->page = page;
+ __entry->netmem = netmem;
__entry->release = release;
- __entry->pfn = page_to_pfn(page);
+ __entry->pfn = netmem_to_pfn(netmem);
),
- TP_printk("page_pool=%p page=%p pfn=0x%lx release=%u",
- __entry->pool, __entry->page, __entry->pfn, __entry->release)
+ TP_printk("page_pool=%p netmem=%p pfn=0x%lx release=%u",
+ __entry->pool, __entry->netmem, __entry->pfn, __entry->release)
);
TRACE_EVENT(page_pool_state_hold,
TP_PROTO(const struct page_pool *pool,
- const struct page *page, u32 hold),
+ struct netmem *netmem, u32 hold),
- TP_ARGS(pool, page, hold),
+ TP_ARGS(pool, netmem, hold),
TP_STRUCT__entry(
__field(const struct page_pool *, pool)
- __field(const struct page *, page)
+ __field(struct netmem *, netmem)
__field(u32, hold)
__field(unsigned long, pfn)
),
TP_fast_assign(
__entry->pool = pool;
- __entry->page = page;
+ __entry->netmem = netmem;
__entry->hold = hold;
- __entry->pfn = page_to_pfn(page);
+ __entry->pfn = netmem_to_pfn(netmem);
),
- TP_printk("page_pool=%p page=%p pfn=0x%lx hold=%u",
- __entry->pool, __entry->page, __entry->pfn, __entry->hold)
+ TP_printk("page_pool=%p netmem=%p pfn=0x%lx hold=%u",
+ __entry->pool, __entry->netmem, __entry->pfn, __entry->hold)
);
TRACE_EVENT(page_pool_update_nid,
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 711cf5d59816..624466235736 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -126,9 +126,10 @@ struct xdp_test_data {
#define TEST_XDP_FRAME_SIZE (PAGE_SIZE - sizeof(struct xdp_page_head))
#define TEST_XDP_MAX_BATCH 256
-static void xdp_test_run_init_page(struct page *page, void *arg)
+static void xdp_test_run_init_page(struct netmem *netmem, void *arg)
{
- struct xdp_page_head *head = phys_to_virt(page_to_phys(page));
+ struct xdp_page_head *head =
+ phys_to_virt(page_to_phys(netmem_to_page(netmem)));
struct xdp_buff *new_ctx, *orig_ctx;
u32 headroom = XDP_PACKET_HEADROOM;
struct xdp_test_data *xdp = arg;
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 0edb9251d98d..965a7bc0a407 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -302,13 +302,14 @@ struct page_pool *page_pool_create(const struct page_pool_params *params)
}
EXPORT_SYMBOL(page_pool_create);
-static void page_pool_return_page(struct page_pool *pool, struct page *page);
+static void page_pool_return_page(struct page_pool *pool,
+ struct netmem *netmem);
-noinline
-static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)
+static noinline struct netmem *
+page_pool_refill_alloc_cache(struct page_pool *pool)
{
struct ptr_ring *r = &pool->ring;
- struct page *page;
+ struct netmem *netmem;
int pref_nid; /* preferred NUMA node */
/* Quicker fallback, avoid locks when ring is empty */
@@ -329,56 +330,56 @@ static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)
/* Refill alloc array, but only if NUMA match */
do {
- page = __ptr_ring_consume(r);
- if (unlikely(!page))
+ netmem = __ptr_ring_consume(r);
+ if (unlikely(!netmem))
break;
- if (likely(page_to_nid(page) == pref_nid)) {
- pool->alloc.cache[pool->alloc.count++] = page;
+ if (likely(page_to_nid(netmem_to_page(netmem)) == pref_nid)) {
+ pool->alloc.cache[pool->alloc.count++] = netmem;
} else {
/* NUMA mismatch;
* (1) release 1 page to page-allocator and
* (2) break out to fallthrough to alloc_pages_node.
* This limit stress on page buddy alloactor.
*/
- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
alloc_stat_inc(pool, waive);
- page = NULL;
+ netmem = NULL;
break;
}
} while (pool->alloc.count < PP_ALLOC_CACHE_REFILL);
/* Return last page */
if (likely(pool->alloc.count > 0)) {
- page = pool->alloc.cache[--pool->alloc.count];
+ netmem = pool->alloc.cache[--pool->alloc.count];
alloc_stat_inc(pool, refill);
}
- return page;
+ return netmem;
}
/* fast path */
-static struct page *__page_pool_get_cached(struct page_pool *pool)
+static struct netmem *__page_pool_get_cached(struct page_pool *pool)
{
- struct page *page;
+ struct netmem *netmem;
/* Caller MUST guarantee safe non-concurrent access, e.g. softirq */
if (likely(pool->alloc.count)) {
/* Fast-path */
- page = pool->alloc.cache[--pool->alloc.count];
+ netmem = pool->alloc.cache[--pool->alloc.count];
alloc_stat_inc(pool, fast);
} else {
- page = page_pool_refill_alloc_cache(pool);
+ netmem = page_pool_refill_alloc_cache(pool);
}
- return page;
+ return netmem;
}
static void page_pool_dma_sync_for_device(struct page_pool *pool,
- struct page *page,
+ struct netmem *netmem,
unsigned int dma_sync_size)
{
- dma_addr_t dma_addr = page_pool_get_dma_addr(page);
+ dma_addr_t dma_addr = page_pool_get_dma_addr_netmem(netmem);
dma_sync_size = min(dma_sync_size, pool->p.max_len);
dma_sync_single_range_for_device(pool->p.dev, dma_addr,
@@ -386,7 +387,7 @@ static void page_pool_dma_sync_for_device(struct page_pool *pool,
pool->p.dma_dir);
}
-static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
+static bool page_pool_dma_map(struct page_pool *pool, struct netmem *netmem)
{
dma_addr_t dma;
@@ -395,18 +396,18 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
* into page private data (i.e 32bit cpu with 64bit DMA caps)
* This mapping is kept for lifetime of page, until leaving pool.
*/
- dma = dma_map_page_attrs(pool->p.dev, page, 0,
- (PAGE_SIZE << pool->p.order),
- pool->p.dma_dir, DMA_ATTR_SKIP_CPU_SYNC |
- DMA_ATTR_WEAK_ORDERING);
+ dma = dma_map_page_attrs(pool->p.dev, netmem_to_page(netmem), 0,
+ (PAGE_SIZE << pool->p.order), pool->p.dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC |
+ DMA_ATTR_WEAK_ORDERING);
if (dma_mapping_error(pool->p.dev, dma))
return false;
- if (page_pool_set_dma_addr(page, dma))
+ if (page_pool_set_dma_addr_netmem(netmem, dma))
goto unmap_failed;
if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
- page_pool_dma_sync_for_device(pool, page, pool->p.max_len);
+ page_pool_dma_sync_for_device(pool, netmem, pool->p.max_len);
return true;
@@ -418,9 +419,10 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
return false;
}
-static void page_pool_set_pp_info(struct page_pool *pool,
- struct page *page)
+static void page_pool_set_pp_info(struct page_pool *pool, struct netmem *netmem)
{
+ struct page *page = netmem_to_page(netmem);
+
page->pp = pool;
page->pp_magic |= PP_SIGNATURE;
@@ -430,13 +432,15 @@ static void page_pool_set_pp_info(struct page_pool *pool,
* is dirtying the same cache line as the page->pp_magic above, so
* the overhead is negligible.
*/
- page_pool_fragment_page(page, 1);
+ page_pool_fragment_netmem(netmem, 1);
if (pool->has_init_callback)
- pool->slow.init_callback(page, pool->slow.init_arg);
+ pool->slow.init_callback(netmem, pool->slow.init_arg);
}
-static void page_pool_clear_pp_info(struct page *page)
+static void page_pool_clear_pp_info(struct netmem *netmem)
{
+ struct page *page = netmem_to_page(netmem);
+
page->pp_magic = 0;
page->pp = NULL;
}
@@ -452,34 +456,34 @@ static struct page *__page_pool_alloc_page_order(struct page_pool *pool,
return NULL;
if ((pool->p.flags & PP_FLAG_DMA_MAP) &&
- unlikely(!page_pool_dma_map(pool, page))) {
+ unlikely(!page_pool_dma_map(pool, page_to_netmem(page)))) {
put_page(page);
return NULL;
}
alloc_stat_inc(pool, slow_high_order);
- page_pool_set_pp_info(pool, page);
+ page_pool_set_pp_info(pool, page_to_netmem(page));
/* Track how many pages are held 'in-flight' */
pool->pages_state_hold_cnt++;
- trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt);
+ trace_page_pool_state_hold(pool, page_to_netmem(page),
+ pool->pages_state_hold_cnt);
return page;
}
/* slow path */
-noinline
-static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
- gfp_t gfp)
+static noinline struct netmem *
+__page_pool_alloc_pages_slow(struct page_pool *pool, gfp_t gfp)
{
const int bulk = PP_ALLOC_CACHE_REFILL;
unsigned int pp_flags = pool->p.flags;
unsigned int pp_order = pool->p.order;
- struct page *page;
+ struct netmem *netmem;
int i, nr_pages;
/* Don't support bulk alloc for high-order pages */
if (unlikely(pp_order))
- return __page_pool_alloc_page_order(pool, gfp);
+ return page_to_netmem(__page_pool_alloc_page_order(pool, gfp));
/* Unnecessary as alloc cache is empty, but guarantees zero count */
if (unlikely(pool->alloc.count > 0))
@@ -488,8 +492,8 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
/* Mark empty alloc.cache slots "empty" for alloc_pages_bulk_array */
memset(&pool->alloc.cache, 0, sizeof(void *) * bulk);
- nr_pages = alloc_pages_bulk_array_node(gfp, pool->p.nid, bulk,
- pool->alloc.cache);
+ nr_pages = alloc_pages_bulk_array_node(
+ gfp, pool->p.nid, bulk, (struct page **)pool->alloc.cache);
if (unlikely(!nr_pages))
return NULL;
@@ -497,51 +501,57 @@ static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool,
* page element have not been (possibly) DMA mapped.
*/
for (i = 0; i < nr_pages; i++) {
- page = pool->alloc.cache[i];
+ netmem = pool->alloc.cache[i];
if ((pp_flags & PP_FLAG_DMA_MAP) &&
- unlikely(!page_pool_dma_map(pool, page))) {
- put_page(page);
+ unlikely(!page_pool_dma_map(pool, netmem))) {
+ put_page(netmem_to_page(netmem));
continue;
}
- page_pool_set_pp_info(pool, page);
- pool->alloc.cache[pool->alloc.count++] = page;
+ page_pool_set_pp_info(pool, netmem);
+ pool->alloc.cache[pool->alloc.count++] = netmem;
/* Track how many pages are held 'in-flight' */
pool->pages_state_hold_cnt++;
- trace_page_pool_state_hold(pool, page,
+ trace_page_pool_state_hold(pool, netmem,
pool->pages_state_hold_cnt);
}
/* Return last page */
if (likely(pool->alloc.count > 0)) {
- page = pool->alloc.cache[--pool->alloc.count];
+ netmem = pool->alloc.cache[--pool->alloc.count];
alloc_stat_inc(pool, slow);
} else {
- page = NULL;
+ netmem = NULL;
}
/* When page just alloc'ed is should/must have refcnt 1. */
- return page;
+ return netmem;
}
/* For using page_pool replace: alloc_pages() API calls, but provide
* synchronization guarantee for allocation side.
*/
-struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
+struct netmem *page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp)
{
- struct page *page;
+ struct netmem *netmem;
/* Fast-path: Get a page from cache */
- page = __page_pool_get_cached(pool);
- if (page)
- return page;
+ netmem = __page_pool_get_cached(pool);
+ if (netmem)
+ return netmem;
/* Slow-path: cache empty, do real allocation */
if (static_branch_unlikely(&page_pool_mem_providers) && pool->mp_ops)
- page = pool->mp_ops->alloc_pages(pool, gfp);
+ netmem = pool->mp_ops->alloc_pages(pool, gfp);
else
- page = __page_pool_alloc_pages_slow(pool, gfp);
- return page;
+ netmem = __page_pool_alloc_pages_slow(pool, gfp);
+ return netmem;
+}
+EXPORT_SYMBOL(page_pool_alloc_netmem);
+
+struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
+{
+ return netmem_to_page(page_pool_alloc_netmem(pool, gfp));
}
EXPORT_SYMBOL(page_pool_alloc_pages);
@@ -569,8 +579,8 @@ s32 page_pool_inflight(const struct page_pool *pool, bool strict)
return inflight;
}
-static __always_inline
-void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
+static __always_inline void __page_pool_release_page_dma(struct page_pool *pool,
+ struct netmem *netmem)
{
dma_addr_t dma;
@@ -580,13 +590,13 @@ void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
*/
return;
- dma = page_pool_get_dma_addr(page);
+ dma = page_pool_get_dma_addr_netmem(netmem);
/* When page is unmapped, it cannot be returned to our pool */
dma_unmap_page_attrs(pool->p.dev, dma,
PAGE_SIZE << pool->p.order, pool->p.dma_dir,
DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING);
- page_pool_set_dma_addr(page, 0);
+ page_pool_set_dma_addr_netmem(netmem, 0);
}
/* Disconnects a page (from a page_pool). API users can have a need
@@ -594,26 +604,26 @@ void __page_pool_release_page_dma(struct page_pool *pool, struct page *page)
* a regular page (that will eventually be returned to the normal
* page-allocator via put_page).
*/
-void page_pool_return_page(struct page_pool *pool, struct page *page)
+void page_pool_return_page(struct page_pool *pool, struct netmem *netmem)
{
int count;
bool put;
put = true;
if (static_branch_unlikely(&page_pool_mem_providers) && pool->mp_ops)
- put = pool->mp_ops->release_page(pool, page);
+ put = pool->mp_ops->release_page(pool, netmem);
else
- __page_pool_release_page_dma(pool, page);
+ __page_pool_release_page_dma(pool, netmem);
/* This may be the last page returned, releasing the pool, so
* it is not safe to reference pool afterwards.
*/
count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt);
- trace_page_pool_state_release(pool, page, count);
+ trace_page_pool_state_release(pool, netmem, count);
if (put) {
- page_pool_clear_pp_info(page);
- put_page(page);
+ page_pool_clear_pp_info(netmem);
+ put_page(netmem_to_page(netmem));
}
/* An optimization would be to call __free_pages(page, pool->p.order)
* knowing page is not part of page-cache (thus avoiding a
@@ -621,14 +631,15 @@ void page_pool_return_page(struct page_pool *pool, struct page *page)
*/
}
-static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
+static bool page_pool_recycle_in_ring(struct page_pool *pool,
+ struct netmem *netmem)
{
int ret;
/* BH protection not needed if current is softirq */
if (in_softirq())
- ret = ptr_ring_produce(&pool->ring, page);
+ ret = ptr_ring_produce(&pool->ring, netmem);
else
- ret = ptr_ring_produce_bh(&pool->ring, page);
+ ret = ptr_ring_produce_bh(&pool->ring, netmem);
if (!ret) {
recycle_stat_inc(pool, ring);
@@ -643,7 +654,7 @@ static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
*
* Caller must provide appropriate safe context.
*/
-static bool page_pool_recycle_in_cache(struct page *page,
+static bool page_pool_recycle_in_cache(struct netmem *netmem,
struct page_pool *pool)
{
if (unlikely(pool->alloc.count == PP_ALLOC_CACHE_SIZE)) {
@@ -652,14 +663,15 @@ static bool page_pool_recycle_in_cache(struct page *page,
}
/* Caller MUST have verified/know (page_ref_count(page) == 1) */
- pool->alloc.cache[pool->alloc.count++] = page;
+ pool->alloc.cache[pool->alloc.count++] = netmem;
recycle_stat_inc(pool, cached);
return true;
}
-static bool __page_pool_page_can_be_recycled(const struct page *page)
+static bool __page_pool_page_can_be_recycled(struct netmem *netmem)
{
- return page_ref_count(page) == 1 && !page_is_pfmemalloc(page);
+ return page_ref_count(netmem_to_page(netmem)) == 1 &&
+ !page_is_pfmemalloc(netmem_to_page(netmem));
}
/* If the page refcnt == 1, this will try to recycle the page.
@@ -668,8 +680,8 @@ static bool __page_pool_page_can_be_recycled(const struct page *page)
* If the page refcnt != 1, then the page will be returned to memory
* subsystem.
*/
-static __always_inline struct page *
-__page_pool_put_page(struct page_pool *pool, struct page *page,
+static __always_inline struct netmem *
+__page_pool_put_page(struct page_pool *pool, struct netmem *netmem,
unsigned int dma_sync_size, bool allow_direct)
{
lockdep_assert_no_hardirq();
@@ -683,19 +695,19 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
* page is NOT reusable when allocated when system is under
* some pressure. (page_is_pfmemalloc)
*/
- if (likely(__page_pool_page_can_be_recycled(page))) {
+ if (likely(__page_pool_page_can_be_recycled(netmem))) {
/* Read barrier done in page_ref_count / READ_ONCE */
if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
- page_pool_dma_sync_for_device(pool, page,
+ page_pool_dma_sync_for_device(pool, netmem,
dma_sync_size);
if (allow_direct && in_softirq() &&
- page_pool_recycle_in_cache(page, pool))
+ page_pool_recycle_in_cache(netmem, pool))
return NULL;
/* Page found as candidate for recycling */
- return page;
+ return netmem;
}
/* Fallback/non-XDP mode: API user have elevated refcnt.
*
@@ -711,21 +723,32 @@ __page_pool_put_page(struct page_pool *pool, struct page *page,
* will be invoking put_page.
*/
recycle_stat_inc(pool, released_refcnt);
- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
return NULL;
}
-void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page,
- unsigned int dma_sync_size, bool allow_direct)
+void page_pool_put_unrefed_netmem(struct page_pool *pool,
+ struct netmem *netmem,
+ unsigned int dma_sync_size,
+ bool allow_direct)
{
- page = __page_pool_put_page(pool, page, dma_sync_size, allow_direct);
- if (page && !page_pool_recycle_in_ring(pool, page)) {
+ netmem =
+ __page_pool_put_page(pool, netmem, dma_sync_size, allow_direct);
+ if (netmem && !page_pool_recycle_in_ring(pool, netmem)) {
/* Cache full, fallback to free pages */
recycle_stat_inc(pool, ring_full);
- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
}
}
+EXPORT_SYMBOL(page_pool_put_unrefed_netmem);
+
+void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page,
+ unsigned int dma_sync_size, bool allow_direct)
+{
+ page_pool_put_unrefed_netmem(pool, page_to_netmem(page), dma_sync_size,
+ allow_direct);
+}
EXPORT_SYMBOL(page_pool_put_unrefed_page);
/**
@@ -750,16 +773,17 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data,
bool in_softirq;
for (i = 0; i < count; i++) {
- struct page *page = virt_to_head_page(data[i]);
+ struct netmem *netmem =
+ page_to_netmem(virt_to_head_page(data[i]));
/* It is not the last user for the page frag case */
- if (!page_pool_is_last_ref(page))
+ if (!page_pool_is_last_ref(netmem))
continue;
- page = __page_pool_put_page(pool, page, -1, false);
+ netmem = __page_pool_put_page(pool, netmem, -1, false);
/* Approved for bulk recycling in ptr_ring cache */
- if (page)
- data[bulk_len++] = page;
+ if (netmem)
+ data[bulk_len++] = netmem;
}
if (unlikely(!bulk_len))
@@ -789,45 +813,45 @@ void page_pool_put_page_bulk(struct page_pool *pool, void **data,
}
EXPORT_SYMBOL(page_pool_put_page_bulk);
-static struct page *page_pool_drain_frag(struct page_pool *pool,
- struct page *page)
+static struct netmem *page_pool_drain_frag(struct page_pool *pool,
+ struct netmem *netmem)
{
long drain_count = BIAS_MAX - pool->frag_users;
/* Some user is still using the page frag */
- if (likely(page_pool_unref_page(page, drain_count)))
+ if (likely(page_pool_unref_netmem(netmem, drain_count)))
return NULL;
- if (__page_pool_page_can_be_recycled(page)) {
+ if (__page_pool_page_can_be_recycled(netmem)) {
if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
- page_pool_dma_sync_for_device(pool, page, -1);
+ page_pool_dma_sync_for_device(pool, netmem, -1);
- return page;
+ return netmem;
}
- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
return NULL;
}
static void page_pool_free_frag(struct page_pool *pool)
{
long drain_count = BIAS_MAX - pool->frag_users;
- struct page *page = pool->frag_page;
+ struct netmem *netmem = pool->frag_page;
pool->frag_page = NULL;
- if (!page || page_pool_unref_page(page, drain_count))
+ if (!netmem || page_pool_unref_netmem(netmem, drain_count))
return;
- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
}
-struct page *page_pool_alloc_frag(struct page_pool *pool,
- unsigned int *offset,
- unsigned int size, gfp_t gfp)
+struct netmem *page_pool_alloc_frag_netmem(struct page_pool *pool,
+ unsigned int *offset,
+ unsigned int size, gfp_t gfp)
{
unsigned int max_size = PAGE_SIZE << pool->p.order;
- struct page *page = pool->frag_page;
+ struct netmem *netmem = pool->frag_page;
if (WARN_ON(size > max_size))
return NULL;
@@ -835,50 +859,58 @@ struct page *page_pool_alloc_frag(struct page_pool *pool,
size = ALIGN(size, dma_get_cache_alignment());
*offset = pool->frag_offset;
- if (page && *offset + size > max_size) {
- page = page_pool_drain_frag(pool, page);
- if (page) {
+ if (netmem && *offset + size > max_size) {
+ netmem = page_pool_drain_frag(pool, netmem);
+ if (netmem) {
alloc_stat_inc(pool, fast);
goto frag_reset;
}
}
- if (!page) {
- page = page_pool_alloc_pages(pool, gfp);
- if (unlikely(!page)) {
+ if (!netmem) {
+ netmem = page_pool_alloc_netmem(pool, gfp);
+ if (unlikely(!netmem)) {
pool->frag_page = NULL;
return NULL;
}
- pool->frag_page = page;
+ pool->frag_page = netmem;
frag_reset:
pool->frag_users = 1;
*offset = 0;
pool->frag_offset = size;
- page_pool_fragment_page(page, BIAS_MAX);
- return page;
+ page_pool_fragment_netmem(netmem, BIAS_MAX);
+ return netmem;
}
pool->frag_users++;
pool->frag_offset = *offset + size;
alloc_stat_inc(pool, fast);
- return page;
+ return netmem;
+}
+EXPORT_SYMBOL(page_pool_alloc_frag_netmem);
+
+struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset,
+ unsigned int size, gfp_t gfp)
+{
+ return netmem_to_page(
+ page_pool_alloc_frag_netmem(pool, offset, size, gfp));
}
EXPORT_SYMBOL(page_pool_alloc_frag);
static void page_pool_empty_ring(struct page_pool *pool)
{
- struct page *page;
+ struct netmem *netmem;
/* Empty recycle ring */
- while ((page = ptr_ring_consume_bh(&pool->ring))) {
+ while ((netmem = ptr_ring_consume_bh(&pool->ring))) {
/* Verify the refcnt invariant of cached pages */
- if (!(page_ref_count(page) == 1))
+ if (!(page_ref_count(netmem_to_page(netmem)) == 1))
pr_crit("%s() page_pool refcnt %d violation\n",
- __func__, page_ref_count(page));
+ __func__, netmem_ref_count(netmem));
- page_pool_return_page(pool, page);
+ page_pool_return_page(pool, netmem);
}
}
@@ -900,7 +932,7 @@ static void __page_pool_destroy(struct page_pool *pool)
static void page_pool_empty_alloc_cache_once(struct page_pool *pool)
{
- struct page *page;
+ struct netmem *netmem;
if (pool->destroy_cnt)
return;
@@ -910,8 +942,8 @@ static void page_pool_empty_alloc_cache_once(struct page_pool *pool)
* call concurrently.
*/
while (pool->alloc.count) {
- page = pool->alloc.cache[--pool->alloc.count];
- page_pool_return_page(pool, page);
+ netmem = pool->alloc.cache[--pool->alloc.count];
+ page_pool_return_page(pool, netmem);
}
}
@@ -1013,15 +1045,15 @@ EXPORT_SYMBOL(page_pool_destroy);
/* Caller must provide appropriate safe context, e.g. NAPI. */
void page_pool_update_nid(struct page_pool *pool, int new_nid)
{
- struct page *page;
+ struct netmem *netmem;
trace_page_pool_update_nid(pool, new_nid);
pool->p.nid = new_nid;
/* Flush pool alloc cache, as refill will check NUMA node */
while (pool->alloc.count) {
- page = pool->alloc.cache[--pool->alloc.count];
- page_pool_return_page(pool, page);
+ netmem = pool->alloc.cache[--pool->alloc.count];
+ page_pool_return_page(pool, netmem);
}
}
EXPORT_SYMBOL(page_pool_update_nid);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 053d220aa2f2..ab86799b7fe4 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -899,8 +899,9 @@ static void skb_clone_fraglist(struct sk_buff *skb)
}
#if IS_ENABLED(CONFIG_PAGE_POOL)
-bool napi_pp_put_page(struct page *page, bool napi_safe)
+bool napi_pp_put_page(struct netmem *netmem, bool napi_safe)
{
+ struct page *page = netmem_to_page(netmem);
bool allow_direct = false;
struct page_pool *pp;
@@ -936,7 +937,7 @@ bool napi_pp_put_page(struct page *page, bool napi_safe)
* The page will be returned to the pool here regardless of the
* 'flipped' fragment being in use or not.
*/
- page_pool_put_full_page(pp, page, allow_direct);
+ page_pool_put_full_netmem(pp, page_to_netmem(page), allow_direct);
return true;
}
@@ -947,7 +948,7 @@ static bool skb_pp_recycle(struct sk_buff *skb, void *data, bool napi_safe)
{
if (!IS_ENABLED(CONFIG_PAGE_POOL) || !skb->pp_recycle)
return false;
- return napi_pp_put_page(virt_to_page(data), napi_safe);
+ return napi_pp_put_page(page_to_netmem(virt_to_page(data)), napi_safe);
}
static void skb_kfree_head(void *head, unsigned int end_offset)
--
2.43.0.472.g3155946c3a-goog
Convert netmem to be a union of struct page and struct netmem. Overload
the LSB of struct netmem* to indicate that it's a net_iov, otherwise
it's a page.
Currently these entries in struct page are rented by the page_pool and
used exclusively by the net stack:
struct {
unsigned long pp_magic;
struct page_pool *pp;
unsigned long _pp_mapping_pad;
unsigned long dma_addr;
atomic_long_t pp_ref_count;
};
Mirror these (and only these) entries into struct net_iov and implement
netmem helpers that can access these common fields regardless of
whether the underlying type is page or net_iov.
Implement checks for net_iov in netmem helpers which delegate to mm
APIs, to ensure net_iov are never passed to the mm stack.
Signed-off-by: Mina Almasry <[email protected]>
---
RFCv5:
- Use netmem instead of page* with LSB set.
- Use pp_ref_count for refcounting net_iov.
- Removed many of the custom checks for netmem.
v1:
- Disable fragmentation support for iov properly.
- fix napi_pp_put_page() path (Yunsheng).
- Use pp_frag_count for devmem refcounting.
---
include/net/netmem.h | 145 ++++++++++++++++++++++++++++++--
include/net/page_pool/helpers.h | 25 +++---
net/core/page_pool.c | 26 +++---
net/core/skbuff.c | 9 +-
4 files changed, 164 insertions(+), 41 deletions(-)
diff --git a/include/net/netmem.h b/include/net/netmem.h
index 31f338f19da0..7557aecc0f78 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -12,11 +12,47 @@
/* net_iov */
+DECLARE_STATIC_KEY_FALSE(page_pool_mem_providers);
+
+/* We overload the LSB of the struct page pointer to indicate whether it's
+ * a page or net_iov.
+ */
+#define NET_IOV 0x01UL
+
struct net_iov {
+ unsigned long __unused_padding;
+ unsigned long pp_magic;
+ struct page_pool *pp;
struct dmabuf_genpool_chunk_owner *owner;
unsigned long dma_addr;
+ atomic_long_t pp_ref_count;
};
+/* These fields in struct page are used by the page_pool and net stack:
+ *
+ * struct {
+ * unsigned long pp_magic;
+ * struct page_pool *pp;
+ * unsigned long _pp_mapping_pad;
+ * unsigned long dma_addr;
+ * atomic_long_t pp_ref_count;
+ * };
+ *
+ * We mirror the page_pool fields here so the page_pool can access these fields
+ * without worrying whether the underlying fields belong to a page or net_iov.
+ *
+ * The non-net stack fields of struct page are private to the mm stack and must
+ * never be mirrored to net_iov.
+ */
+#define NET_IOV_ASSERT_OFFSET(pg, iov) \
+ static_assert(offsetof(struct page, pg) == \
+ offsetof(struct net_iov, iov))
+NET_IOV_ASSERT_OFFSET(pp_magic, pp_magic);
+NET_IOV_ASSERT_OFFSET(pp, pp);
+NET_IOV_ASSERT_OFFSET(dma_addr, dma_addr);
+NET_IOV_ASSERT_OFFSET(pp_ref_count, pp_ref_count);
+#undef NET_IOV_ASSERT_OFFSET
+
static inline struct dmabuf_genpool_chunk_owner *
net_iov_owner(const struct net_iov *niov)
{
@@ -47,19 +83,25 @@ net_iov_binding(const struct net_iov *niov)
struct netmem {
union {
struct page page;
-
- /* Stub to prevent compiler implicitly converting from page*
- * to netmem_t* and vice versa.
- *
- * Other memory type(s) net stack would like to support
- * can be added to this union.
- */
- void *addr;
+ struct net_iov niov;
};
};
+static inline bool netmem_is_net_iov(const struct netmem *netmem)
+{
+#ifdef CONFIG_PAGE_POOL
+ return static_branch_unlikely(&page_pool_mem_providers) &&
+ (unsigned long)netmem & NET_IOV;
+#else
+ return false;
+#endif
+}
+
static inline struct page *netmem_to_page(struct netmem *netmem)
{
+ if (WARN_ON_ONCE(netmem_is_net_iov(netmem)))
+ return NULL;
+
return &netmem->page;
}
@@ -70,17 +112,104 @@ static inline struct netmem *page_to_netmem(struct page *page)
static inline int netmem_ref_count(struct netmem *netmem)
{
+ /* The non-pp refcount of netmem is always 1. On netmem, we only support
+ * pp refcounting.
+ */
+ if (netmem_is_net_iov(netmem))
+ return 1;
+
return page_ref_count(netmem_to_page(netmem));
}
static inline unsigned long netmem_to_pfn(struct netmem *netmem)
{
+ if (netmem_is_net_iov(netmem))
+ return 0;
+
return page_to_pfn(netmem_to_page(netmem));
}
+static inline struct net_iov *__netmem_clear_lsb(struct netmem *netmem)
+{
+ return (struct net_iov *)((unsigned long)netmem & ~NET_IOV);
+}
+
+static inline unsigned long netmem_get_pp_magic(struct netmem *netmem)
+{
+ return __netmem_clear_lsb(netmem)->pp_magic;
+}
+
+static inline void netmem_or_pp_magic(struct netmem *netmem,
+ unsigned long pp_magic)
+{
+ __netmem_clear_lsb(netmem)->pp_magic |= pp_magic;
+}
+
+static inline void netmem_clear_pp_magic(struct netmem *netmem)
+{
+ __netmem_clear_lsb(netmem)->pp_magic = 0;
+}
+
+static inline struct page_pool *netmem_get_pp(struct netmem *netmem)
+{
+ return __netmem_clear_lsb(netmem)->pp;
+}
+
+static inline void netmem_set_pp(struct netmem *netmem, struct page_pool *pool)
+{
+ __netmem_clear_lsb(netmem)->pp = pool;
+}
+
+static inline unsigned long netmem_get_dma_addr(struct netmem *netmem)
+{
+ return __netmem_clear_lsb(netmem)->dma_addr;
+}
+
+static inline void netmem_set_dma_addr(struct netmem *netmem,
+ unsigned long dma_addr)
+{
+ __netmem_clear_lsb(netmem)->dma_addr = dma_addr;
+}
+
+static inline atomic_long_t *netmem_get_pp_ref_count_ref(struct netmem *netmem)
+{
+ return &__netmem_clear_lsb(netmem)->pp_ref_count;
+}
+
+static inline bool netmem_is_pref_nid(struct netmem *netmem, int pref_nid)
+{
+ /* Assume net_iov are on the preferred node without actually
+ * checking...
+ *
+ * This check is only used to check for recycling memory in the page
+ * pool's fast paths. Currently the only implementation of net_iov
+ * is dmabuf device memory. It's a deliberate decision by the user to
+ * bind a certain dmabuf to a certain netdev, and the netdev rx queue
+ * would not be able to reallocate memory from another dmabuf that
+ * exists on the preferred node, so, this check doesn't make much sense
+ * in this case. Assume all net_iovs can be recycled for now.
+ */
+ if (netmem_is_net_iov(netmem))
+ return true;
+
+ return page_to_nid(netmem_to_page(netmem)) == pref_nid;
+}
+
static inline struct netmem *netmem_compound_head(struct netmem *netmem)
{
+ /* niov are never compounded */
+ if (netmem_is_net_iov(netmem))
+ return netmem;
+
return page_to_netmem(compound_head(netmem_to_page(netmem)));
}
+static inline void *netmem_address(struct netmem *netmem)
+{
+ if (netmem_is_net_iov(netmem))
+ return NULL;
+
+ return page_address(netmem_to_page(netmem));
+}
+
#endif /* _NET_NETMEM_H */
diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
index c71969279284..8827518379a8 100644
--- a/include/net/page_pool/helpers.h
+++ b/include/net/page_pool/helpers.h
@@ -215,7 +215,7 @@ inline enum dma_data_direction page_pool_get_dma_dir(struct page_pool *pool)
static inline void page_pool_fragment_netmem(struct netmem *netmem, long nr)
{
- atomic_long_set(&netmem_to_page(netmem)->pp_ref_count, nr);
+ atomic_long_set(netmem_get_pp_ref_count_ref(netmem), nr);
}
/**
@@ -243,7 +243,7 @@ static inline void page_pool_fragment_page(struct page *page, long nr)
static inline long page_pool_unref_netmem(struct netmem *netmem, long nr)
{
- struct page *page = netmem_to_page(netmem);
+ atomic_long_t *pp_ref_count = netmem_get_pp_ref_count_ref(netmem);
long ret;
/* If nr == pp_ref_count then we have cleared all remaining
@@ -260,19 +260,19 @@ static inline long page_pool_unref_netmem(struct netmem *netmem, long nr)
* initially, and only overwrite it when the page is partitioned into
* more than one piece.
*/
- if (atomic_long_read(&page->pp_ref_count) == nr) {
+ if (atomic_long_read(pp_ref_count) == nr) {
/* As we have ensured nr is always one for constant case using
* the BUILD_BUG_ON(), only need to handle the non-constant case
* here for pp_ref_count draining, which is a rare case.
*/
BUILD_BUG_ON(__builtin_constant_p(nr) && nr != 1);
if (!__builtin_constant_p(nr))
- atomic_long_set(&page->pp_ref_count, 1);
+ atomic_long_set(pp_ref_count, 1);
return 0;
}
- ret = atomic_long_sub_return(nr, &page->pp_ref_count);
+ ret = atomic_long_sub_return(nr, pp_ref_count);
WARN_ON(ret < 0);
/* We are the last user here too, reset pp_ref_count back to 1 to
@@ -281,7 +281,7 @@ static inline long page_pool_unref_netmem(struct netmem *netmem, long nr)
* page_pool_unref_page() currently.
*/
if (unlikely(!ret))
- atomic_long_set(&page->pp_ref_count, 1);
+ atomic_long_set(pp_ref_count, 1);
return ret;
}
@@ -391,9 +391,7 @@ static inline void page_pool_free_va(struct page_pool *pool, void *va,
static inline dma_addr_t page_pool_get_dma_addr_netmem(struct netmem *netmem)
{
- struct page *page = netmem_to_page(netmem);
-
- dma_addr_t ret = page->dma_addr;
+ dma_addr_t ret = netmem_get_dma_addr(netmem);
if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
ret <<= PAGE_SHIFT;
@@ -416,18 +414,17 @@ static inline dma_addr_t page_pool_get_dma_addr(struct page *page)
static inline bool page_pool_set_dma_addr_netmem(struct netmem *netmem,
dma_addr_t addr)
{
- struct page *page = netmem_to_page(netmem);
-
if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) {
- page->dma_addr = addr >> PAGE_SHIFT;
+ netmem_set_dma_addr(netmem, addr >> PAGE_SHIFT);
/* We assume page alignment to shave off bottom bits,
* if this "compression" doesn't work we need to drop.
*/
- return addr != (dma_addr_t)page->dma_addr << PAGE_SHIFT;
+ return addr != (dma_addr_t)netmem_get_dma_addr(netmem)
+ << PAGE_SHIFT;
}
- page->dma_addr = addr;
+ netmem_set_dma_addr(netmem, addr);
return false;
}
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 965a7bc0a407..173158a3dd61 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -25,7 +25,7 @@
#include "page_pool_priv.h"
-static DEFINE_STATIC_KEY_FALSE(page_pool_mem_providers);
+DEFINE_STATIC_KEY_FALSE(page_pool_mem_providers);
#define DEFER_TIME (msecs_to_jiffies(1000))
#define DEFER_WARN_INTERVAL (60 * HZ)
@@ -334,7 +334,7 @@ page_pool_refill_alloc_cache(struct page_pool *pool)
if (unlikely(!netmem))
break;
- if (likely(page_to_nid(netmem_to_page(netmem)) == pref_nid)) {
+ if (likely(netmem_is_pref_nid(netmem, pref_nid))) {
pool->alloc.cache[pool->alloc.count++] = netmem;
} else {
/* NUMA mismatch;
@@ -421,10 +421,8 @@ static bool page_pool_dma_map(struct page_pool *pool, struct netmem *netmem)
static void page_pool_set_pp_info(struct page_pool *pool, struct netmem *netmem)
{
- struct page *page = netmem_to_page(netmem);
-
- page->pp = pool;
- page->pp_magic |= PP_SIGNATURE;
+ netmem_set_pp(netmem, pool);
+ netmem_or_pp_magic(netmem, PP_SIGNATURE);
/* Ensuring all pages have been split into one fragment initially:
* page_pool_set_pp_info() is only called once for every page when it
@@ -439,10 +437,8 @@ static void page_pool_set_pp_info(struct page_pool *pool, struct netmem *netmem)
static void page_pool_clear_pp_info(struct netmem *netmem)
{
- struct page *page = netmem_to_page(netmem);
-
- page->pp_magic = 0;
- page->pp = NULL;
+ netmem_clear_pp_magic(netmem);
+ netmem_set_pp(netmem, NULL);
}
static struct page *__page_pool_alloc_page_order(struct page_pool *pool,
@@ -670,8 +666,9 @@ static bool page_pool_recycle_in_cache(struct netmem *netmem,
static bool __page_pool_page_can_be_recycled(struct netmem *netmem)
{
- return page_ref_count(netmem_to_page(netmem)) == 1 &&
- !page_is_pfmemalloc(netmem_to_page(netmem));
+ return netmem_is_net_iov(netmem) ||
+ (page_ref_count(netmem_to_page(netmem)) == 1 &&
+ !page_is_pfmemalloc(netmem_to_page(netmem)));
}
/* If the page refcnt == 1, this will try to recycle the page.
@@ -693,7 +690,7 @@ __page_pool_put_page(struct page_pool *pool, struct netmem *netmem,
* refcnt == 1 means page_pool owns page, and can recycle it.
*
* page is NOT reusable when allocated when system is under
- * some pressure. (page_is_pfmemalloc)
+ * some pressure. (page_pool_page_is_pfmemalloc)
*/
if (likely(__page_pool_page_can_be_recycled(netmem))) {
/* Read barrier done in page_ref_count / READ_ONCE */
@@ -709,6 +706,7 @@ __page_pool_put_page(struct page_pool *pool, struct netmem *netmem,
/* Page found as candidate for recycling */
return netmem;
}
+
/* Fallback/non-XDP mode: API user have elevated refcnt.
*
* Many drivers split up the page into fragments, and some
@@ -906,7 +904,7 @@ static void page_pool_empty_ring(struct page_pool *pool)
/* Empty recycle ring */
while ((netmem = ptr_ring_consume_bh(&pool->ring))) {
/* Verify the refcnt invariant of cached pages */
- if (!(page_ref_count(netmem_to_page(netmem)) == 1))
+ if (!(netmem_ref_count(netmem) == 1))
pr_crit("%s() page_pool refcnt %d violation\n",
__func__, netmem_ref_count(netmem));
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index ab86799b7fe4..96f85543f1dc 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -901,11 +901,10 @@ static void skb_clone_fraglist(struct sk_buff *skb)
#if IS_ENABLED(CONFIG_PAGE_POOL)
bool napi_pp_put_page(struct netmem *netmem, bool napi_safe)
{
- struct page *page = netmem_to_page(netmem);
bool allow_direct = false;
struct page_pool *pp;
- page = compound_head(page);
+ netmem = netmem_compound_head(netmem);
/* page->pp_magic is OR'ed with PP_SIGNATURE after the allocation
* in order to preserve any existing bits, such as bit 0 for the
@@ -914,10 +913,10 @@ bool napi_pp_put_page(struct netmem *netmem, bool napi_safe)
* and page_is_pfmemalloc() is checked in __page_pool_put_page()
* to avoid recycling the pfmemalloc page.
*/
- if (unlikely((page->pp_magic & ~0x3UL) != PP_SIGNATURE))
+ if (unlikely((netmem_get_pp_magic(netmem) & ~0x3UL) != PP_SIGNATURE))
return false;
- pp = page->pp;
+ pp = netmem_get_pp(netmem);
/* Allow direct recycle if we have reasons to believe that we are
* in the same context as the consumer would run, so there's
@@ -937,7 +936,7 @@ bool napi_pp_put_page(struct netmem *netmem, bool napi_safe)
* The page will be returned to the pool here regardless of the
* 'flipped' fragment being in use or not.
*/
- page_pool_put_full_netmem(pp, page_to_netmem(page), allow_direct);
+ page_pool_put_full_netmem(pp, netmem, allow_direct);
return true;
}
--
2.43.0.472.g3155946c3a-goog
Implement a memory provider that allocates dmabuf devmem in the form of
net_iov.
The provider receives a reference to the struct netdev_dmabuf_binding
via the pool->mp_priv pointer. The driver needs to set this pointer for
the provider in the net_iov.
The provider obtains a reference on the netdev_dmabuf_binding which
guarantees the binding and the underlying mapping remains alive until
the provider is destroyed.
Usage of PP_FLAG_DMA_MAP is required for this memory provide such that
the page_pool can provide the driver with the dma-addrs of the devmem.
Support for PP_FLAG_DMA_SYNC_DEV is omitted for simplicity & p.order !=
0.
Signed-off-by: Willem de Bruijn <[email protected]>
Signed-off-by: Kaiyuan Zhang <[email protected]>
Signed-off-by: Mina Almasry <[email protected]>
---
v2:
- Disable devmem for p.order != 0
v1:
- static_branch check in page_is_page_pool_iov() (Willem & Paolo).
- PP_DEVMEM -> PP_IOV (David).
- Require PP_FLAG_DMA_MAP (Jakub).
memory provider
---
include/net/netmem.h | 14 ++++++
include/net/page_pool/types.h | 2 +
net/core/page_pool.c | 93 +++++++++++++++++++++++++++++++++++
3 files changed, 109 insertions(+)
diff --git a/include/net/netmem.h b/include/net/netmem.h
index 7557aecc0f78..ab3824b7b789 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -97,6 +97,20 @@ static inline bool netmem_is_net_iov(const struct netmem *netmem)
#endif
}
+static inline struct net_iov *netmem_to_net_iov(struct netmem *netmem)
+{
+ if (netmem_is_net_iov(netmem))
+ return (struct net_iov *)((unsigned long)netmem & ~NET_IOV);
+
+ DEBUG_NET_WARN_ON_ONCE(true);
+ return NULL;
+}
+
+static inline struct netmem *net_iov_to_netmem(struct net_iov *niov)
+{
+ return (struct netmem *)((unsigned long)niov | NET_IOV);
+}
+
static inline struct page *netmem_to_page(struct netmem *netmem)
{
if (WARN_ON_ONCE(netmem_is_net_iov(netmem)))
diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index 433ae9ae658b..3ddef7d7ba74 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -134,6 +134,8 @@ struct memory_provider_ops {
bool (*release_page)(struct page_pool *pool, struct netmem *netmem);
};
+extern const struct memory_provider_ops dmabuf_devmem_ops;
+
struct page_pool {
struct page_pool_params_fast p;
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 173158a3dd61..231840112956 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -12,6 +12,7 @@
#include <net/page_pool/helpers.h>
#include <net/xdp.h>
+#include <net/netdev_rx_queue.h>
#include <linux/dma-direction.h>
#include <linux/dma-mapping.h>
@@ -20,12 +21,15 @@
#include <linux/poison.h>
#include <linux/ethtool.h>
#include <linux/netdevice.h>
+#include <linux/genalloc.h>
+#include <net/devmem.h>
#include <trace/events/page_pool.h>
#include "page_pool_priv.h"
DEFINE_STATIC_KEY_FALSE(page_pool_mem_providers);
+EXPORT_SYMBOL(page_pool_mem_providers);
#define DEFER_TIME (msecs_to_jiffies(1000))
#define DEFER_WARN_INTERVAL (60 * HZ)
@@ -175,6 +179,7 @@ static void page_pool_producer_unlock(struct page_pool *pool,
static int page_pool_init(struct page_pool *pool,
const struct page_pool_params *params)
{
+ struct netdev_dmabuf_binding *binding = NULL;
unsigned int ring_qsize = 1024; /* Default */
int err;
@@ -237,6 +242,14 @@ static int page_pool_init(struct page_pool *pool,
/* Driver calling page_pool_create() also call page_pool_destroy() */
refcount_set(&pool->user_cnt, 1);
+ if (pool->p.queue)
+ binding = READ_ONCE(pool->p.queue->binding);
+
+ if (binding) {
+ pool->mp_ops = &dmabuf_devmem_ops;
+ pool->mp_priv = binding;
+ }
+
if (pool->mp_ops) {
err = pool->mp_ops->init(pool);
if (err) {
@@ -1055,3 +1068,83 @@ void page_pool_update_nid(struct page_pool *pool, int new_nid)
}
}
EXPORT_SYMBOL(page_pool_update_nid);
+
+/*** "Dmabuf devmem memory provider" ***/
+
+static int mp_dmabuf_devmem_init(struct page_pool *pool)
+{
+ struct netdev_dmabuf_binding *binding = pool->mp_priv;
+
+ if (!binding)
+ return -EINVAL;
+
+ if (!(pool->p.flags & PP_FLAG_DMA_MAP))
+ return -EOPNOTSUPP;
+
+ if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
+ return -EOPNOTSUPP;
+
+ if (pool->p.order != 0)
+ return -E2BIG;
+
+ netdev_dmabuf_binding_get(binding);
+ return 0;
+}
+
+static struct netmem *mp_dmabuf_devmem_alloc_pages(struct page_pool *pool,
+ gfp_t gfp)
+{
+ struct netdev_dmabuf_binding *binding = pool->mp_priv;
+ struct netmem *netmem;
+ struct net_iov *niov;
+ dma_addr_t dma_addr;
+
+ niov = netdev_alloc_dmabuf(binding);
+ if (!niov)
+ return NULL;
+
+ dma_addr = net_iov_dma_addr(niov);
+
+ netmem = net_iov_to_netmem(niov);
+
+ page_pool_set_pp_info(pool, netmem);
+
+ if (page_pool_set_dma_addr_netmem(netmem, dma_addr))
+ goto err_free;
+
+ pool->pages_state_hold_cnt++;
+ trace_page_pool_state_hold(pool, netmem, pool->pages_state_hold_cnt);
+ return netmem;
+
+err_free:
+ netdev_free_dmabuf(niov);
+ return NULL;
+}
+
+static void mp_dmabuf_devmem_destroy(struct page_pool *pool)
+{
+ struct netdev_dmabuf_binding *binding = pool->mp_priv;
+
+ netdev_dmabuf_binding_put(binding);
+}
+
+static bool mp_dmabuf_devmem_release_page(struct page_pool *pool,
+ struct netmem *netmem)
+{
+ WARN_ON_ONCE(!netmem_is_net_iov(netmem));
+
+ page_pool_clear_pp_info(netmem);
+
+ netdev_free_dmabuf(netmem_to_net_iov(netmem));
+
+ /* We don't want the page pool put_page()ing our net_iovs. */
+ return false;
+}
+
+const struct memory_provider_ops dmabuf_devmem_ops = {
+ .init = mp_dmabuf_devmem_init,
+ .destroy = mp_dmabuf_devmem_destroy,
+ .alloc_pages = mp_dmabuf_devmem_alloc_pages,
+ .release_page = mp_dmabuf_devmem_release_page,
+};
+EXPORT_SYMBOL(dmabuf_devmem_ops);
--
2.43.0.472.g3155946c3a-goog
Make skb_frag_page() fail in the case where the frag is not backed
by a page, and fix its relevant callers to handle this case.
Signed-off-by: Mina Almasry <[email protected]>
---
Changes in v1:
- Fix illegal_highdma() (Yunsheng).
- Rework napi_pp_put_page() slightly to reduce code churn (Willem).
(cherry picked from commit e11c8035ed635e22aab224a89c48d93b5e881278)
also squashed assorted fixes
---
include/linux/skbuff.h | 47 +++++++++++++++++++++++++++++++++++++-----
net/core/dev.c | 3 ++-
net/core/gro.c | 2 +-
net/core/skbuff.c | 11 ++++++++++
net/ipv4/tcp.c | 3 +++
5 files changed, 59 insertions(+), 7 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 1189d8d22da8..890fc2b94fc7 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3452,17 +3452,53 @@ static inline void skb_frag_off_copy(skb_frag_t *fragto,
fragto->bv_offset = fragfrom->bv_offset;
}
+/* Returns true if the skb_frag contains a net_iov. */
+static inline bool skb_frag_is_net_iov(const skb_frag_t *frag)
+{
+ return netmem_is_net_iov(frag->bv_page);
+}
+
+/**
+ * skb_frag_net_iov - retrieve the net_iov referred to by fragment
+ * @frag: the fragment
+ *
+ * Returns the &struct net_iov associated with @frag. Returns NULL if this
+ * frag has no associated net_iov.
+ */
+static inline struct net_iov *skb_frag_net_iov(const skb_frag_t *frag)
+{
+ if (!skb_frag_is_net_iov(frag))
+ return NULL;
+
+ return netmem_to_net_iov(frag->bv_page);
+}
+
/**
* skb_frag_page - retrieve the page referred to by a paged fragment
* @frag: the paged fragment
*
- * Returns the &struct page associated with @frag.
+ * Returns the &struct page associated with @frag. Returns NULL if this frag
+ * has no associated page.
*/
static inline struct page *skb_frag_page(const skb_frag_t *frag)
{
+ if (skb_frag_is_net_iov(frag))
+ return NULL;
+
return netmem_to_page(frag->bv_page);
}
+/**
+ * skb_frag_netmem - retrieve the netmem referred to by a fragment
+ * @frag: the fragment
+ *
+ * Returns the &struct netmem associated with @frag.
+ */
+static inline struct netmem *skb_frag_netmem(const skb_frag_t *frag)
+{
+ return frag->bv_page;
+}
+
/**
* __skb_frag_ref - take an addition reference on a paged fragment.
* @frag: the paged fragment
@@ -3491,13 +3527,11 @@ bool napi_pp_put_page(struct netmem *netmem, bool napi_safe);
static inline void
napi_frag_unref(skb_frag_t *frag, bool recycle, bool napi_safe)
{
- struct page *page = skb_frag_page(frag);
-
#ifdef CONFIG_PAGE_POOL
- if (recycle && napi_pp_put_page(page_to_netmem(page), napi_safe))
+ if (recycle && napi_pp_put_page(skb_frag_netmem(frag), napi_safe))
return;
#endif
- put_page(page);
+ put_page(skb_frag_page(frag));
}
/**
@@ -3537,6 +3571,9 @@ static inline void skb_frag_unref(struct sk_buff *skb, int f)
*/
static inline void *skb_frag_address(const skb_frag_t *frag)
{
+ if (!skb_frag_page(frag))
+ return NULL;
+
return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
}
diff --git a/net/core/dev.c b/net/core/dev.c
index 20ba528ef426..ad616b3c8e35 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3709,8 +3709,9 @@ static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
if (!(dev->features & NETIF_F_HIGHDMA)) {
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+ struct page *page = skb_frag_page(frag);
- if (PageHighMem(skb_frag_page(frag)))
+ if (page && PageHighMem(page))
return 1;
}
}
diff --git a/net/core/gro.c b/net/core/gro.c
index 0759277dc14e..42d7f6755f32 100644
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -376,7 +376,7 @@ static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff)
NAPI_GRO_CB(skb)->frag0 = NULL;
NAPI_GRO_CB(skb)->frag0_len = 0;
- if (!skb_headlen(skb) && pinfo->nr_frags &&
+ if (!skb_headlen(skb) && pinfo->nr_frags && skb_frag_page(frag0) &&
!PageHighMem(skb_frag_page(frag0)) &&
(!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) {
NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 96f85543f1dc..671775bad5f9 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1239,6 +1239,14 @@ void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt)
struct page *p;
u8 *vaddr;
+ if (skb_frag_is_net_iov(frag)) {
+ printk("%sskb frag %d: not readable\n", level, i);
+ len -= frag->bv_len;
+ if (!len)
+ break;
+ continue;
+ }
+
skb_frag_foreach_page(frag, skb_frag_off(frag),
skb_frag_size(frag), p, p_off, p_len,
copied) {
@@ -3004,6 +3012,9 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) {
const skb_frag_t *f = &skb_shinfo(skb)->frags[seg];
+ if (WARN_ON_ONCE(!skb_frag_page(f)))
+ return false;
+
if (__splice_segment(skb_frag_page(f),
skb_frag_off(f), skb_frag_size(f),
offset, len, spd, false, sk, pipe))
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1d6b80145efb..82485af12cdc 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2157,6 +2157,9 @@ static int tcp_zerocopy_receive(struct sock *sk,
break;
}
page = skb_frag_page(frags);
+ if (WARN_ON_ONCE(!page))
+ break;
+
prefetchw(page);
pages[pages_to_map++] = page;
length += PAGE_SIZE;
--
2.43.0.472.g3155946c3a-goog
For device memory TCP, we expect the skb headers to be available in host
memory for access, and we expect the skb frags to be in device memory
and unaccessible to the host. We expect there to be no mixing and
matching of device memory frags (unaccessible) with host memory frags
(accessible) in the same skb.
Add a skb->devmem flag which indicates whether the frags in this skb
are device memory frags or not.
__skb_fill_netmem_desc() now checks frags added to skbs for net_iov,
and marks the skb as skb->devmem accordingly.
Add checks through the network stack to avoid accessing the frags of
devmem skbs and avoid coalescing devmem skbs with non devmem skbs.
Signed-off-by: Willem de Bruijn <[email protected]>
Signed-off-by: Kaiyuan Zhang <[email protected]>
Signed-off-by: Mina Almasry <[email protected]>
---
Changes in v1:
- Rename devmem -> dmabuf (David).
- Flip skb_frags_not_readable (Jakub).
---
include/linux/skbuff.h | 19 ++++++++++--
include/net/tcp.h | 5 +--
net/core/datagram.c | 6 ++++
net/core/gro.c | 5 ++-
net/core/skbuff.c | 69 ++++++++++++++++++++++++++++++++++++------
net/ipv4/tcp.c | 3 ++
net/ipv4/tcp_input.c | 13 ++++++--
net/ipv4/tcp_output.c | 5 ++-
net/packet/af_packet.c | 4 +--
9 files changed, 108 insertions(+), 21 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 890fc2b94fc7..07691a649b05 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -820,6 +820,8 @@ typedef unsigned char *sk_buff_data_t;
* @csum_level: indicates the number of consecutive checksums found in
* the packet minus one that have been verified as
* CHECKSUM_UNNECESSARY (max 3)
+ * @dmabuf: indicates that all the fragments in this skb are backed by
+ * dmabuf.
* @dst_pending_confirm: need to confirm neighbour
* @decrypted: Decrypted SKB
* @slow_gro: state present at GRO time, slower prepare step required
@@ -1006,7 +1008,7 @@ struct sk_buff {
#if IS_ENABLED(CONFIG_IP_SCTP)
__u8 csum_not_inet:1;
#endif
-
+ __u8 dmabuf:1;
#if defined(CONFIG_NET_SCHED) || defined(CONFIG_NET_XGRESS)
__u16 tc_index; /* traffic control index */
#endif
@@ -1781,6 +1783,12 @@ static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb)
__skb_zcopy_downgrade_managed(skb);
}
+/* Return true if frags in this skb are readable by the host. */
+static inline bool skb_frags_readable(const struct sk_buff *skb)
+{
+ return !skb->dmabuf;
+}
+
static inline void skb_mark_not_on_list(struct sk_buff *skb)
{
skb->next = NULL;
@@ -2498,10 +2506,17 @@ static inline void __skb_fill_netmem_desc(struct sk_buff *skb, int i,
struct netmem *netmem, int off,
int size)
{
- struct page *page = netmem_to_page(netmem);
+ struct page *page;
__skb_fill_netmem_desc_noacc(skb_shinfo(skb), i, netmem, off, size);
+ if (netmem_is_net_iov(netmem)) {
+ skb->dmabuf = true;
+ return;
+ }
+
+ page = netmem_to_page(netmem);
+
/* Propagate page pfmemalloc to the skb if we can. The problem is
* that not all callers have unique ownership of the page but rely
* on page_is_pfmemalloc doing the right thing(tm).
diff --git a/include/net/tcp.h b/include/net/tcp.h
index f5ca4abaee8b..5ecd5307f485 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1017,7 +1017,7 @@ static inline int tcp_skb_mss(const struct sk_buff *skb)
static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb)
{
- return likely(!TCP_SKB_CB(skb)->eor);
+ return likely(!TCP_SKB_CB(skb)->eor && skb_frags_readable(skb));
}
static inline bool tcp_skb_can_collapse(const struct sk_buff *to,
@@ -1025,7 +1025,8 @@ static inline bool tcp_skb_can_collapse(const struct sk_buff *to,
{
return likely(tcp_skb_can_collapse_to(to) &&
mptcp_skb_can_collapse(to, from) &&
- skb_pure_zcopy_same(to, from));
+ skb_pure_zcopy_same(to, from) &&
+ skb_frags_readable(to) == skb_frags_readable(from));
}
/* Events passed to congestion control interface */
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 103d46fa0eeb..f28472ddbaa4 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -426,6 +426,9 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset,
return 0;
}
+ if (!skb_frags_readable(skb))
+ goto short_copy;
+
/* Copy paged appendix. Hmm... why does this look so complicated? */
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
@@ -638,6 +641,9 @@ int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk,
if (msg && msg->msg_ubuf && msg->sg_from_iter)
return msg->sg_from_iter(sk, skb, from, length);
+ if (!skb_frags_readable(skb))
+ return -EFAULT;
+
frag = skb_shinfo(skb)->nr_frags;
while (length && iov_iter_count(from)) {
diff --git a/net/core/gro.c b/net/core/gro.c
index 42d7f6755f32..26df48f1b355 100644
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -390,6 +390,9 @@ static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
{
struct skb_shared_info *pinfo = skb_shinfo(skb);
+ if (WARN_ON_ONCE(!skb_frags_readable(skb)))
+ return;
+
BUG_ON(skb->end - skb->tail < grow);
memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
@@ -411,7 +414,7 @@ static void gro_try_pull_from_frag0(struct sk_buff *skb)
{
int grow = skb_gro_offset(skb) - skb_headlen(skb);
- if (grow > 0)
+ if (grow > 0 && skb_frags_readable(skb))
gro_pull_from_frag0(skb, grow);
}
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 671775bad5f9..298593024e42 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1824,6 +1824,9 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
if (skb_shared(skb) || skb_unclone(skb, gfp_mask))
return -EINVAL;
+ if (!skb_frags_readable(skb))
+ return -EFAULT;
+
if (!num_frags)
goto release;
@@ -1995,8 +1998,12 @@ struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask)
{
int headerlen = skb_headroom(skb);
unsigned int size = skb_end_offset(skb) + skb->data_len;
- struct sk_buff *n = __alloc_skb(size, gfp_mask,
- skb_alloc_rx_flag(skb), NUMA_NO_NODE);
+ struct sk_buff *n;
+
+ if (!skb_frags_readable(skb))
+ return NULL;
+
+ n = __alloc_skb(size, gfp_mask, skb_alloc_rx_flag(skb), NUMA_NO_NODE);
if (!n)
return NULL;
@@ -2322,14 +2329,16 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
int newheadroom, int newtailroom,
gfp_t gfp_mask)
{
- /*
- * Allocate the copy buffer
- */
- struct sk_buff *n = __alloc_skb(newheadroom + skb->len + newtailroom,
- gfp_mask, skb_alloc_rx_flag(skb),
- NUMA_NO_NODE);
int oldheadroom = skb_headroom(skb);
int head_copy_len, head_copy_off;
+ struct sk_buff *n;
+
+ if (!skb_frags_readable(skb))
+ return NULL;
+
+ /* Allocate the copy buffer */
+ n = __alloc_skb(newheadroom + skb->len + newtailroom, gfp_mask,
+ skb_alloc_rx_flag(skb), NUMA_NO_NODE);
if (!n)
return NULL;
@@ -2668,6 +2677,9 @@ void *__pskb_pull_tail(struct sk_buff *skb, int delta)
*/
int i, k, eat = (skb->tail + delta) - skb->end;
+ if (!skb_frags_readable(skb))
+ return NULL;
+
if (eat > 0 || skb_cloned(skb)) {
if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0,
GFP_ATOMIC))
@@ -2821,6 +2833,9 @@ int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len)
to += copy;
}
+ if (!skb_frags_readable(skb))
+ goto fault;
+
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
skb_frag_t *f = &skb_shinfo(skb)->frags[i];
@@ -3009,6 +3024,9 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
/*
* then map the fragments
*/
+ if (!skb_frags_readable(skb))
+ return false;
+
for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) {
const skb_frag_t *f = &skb_shinfo(skb)->frags[seg];
@@ -3232,6 +3250,9 @@ int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len)
from += copy;
}
+ if (!skb_frags_readable(skb))
+ goto fault;
+
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
int end;
@@ -3311,6 +3332,9 @@ __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
pos = copy;
}
+ if (!skb_frags_readable(skb))
+ return 0;
+
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
@@ -3411,6 +3435,9 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
pos = copy;
}
+ if (!skb_frags_readable(skb))
+ return 0;
+
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
@@ -3902,7 +3929,9 @@ static inline void skb_split_inside_header(struct sk_buff *skb,
skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i];
skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags;
+ skb1->dmabuf = skb->dmabuf;
skb_shinfo(skb)->nr_frags = 0;
+ skb->dmabuf = 0;
skb1->data_len = skb->data_len;
skb1->len += skb1->data_len;
skb->data_len = 0;
@@ -3916,6 +3945,7 @@ static inline void skb_split_no_header(struct sk_buff *skb,
{
int i, k = 0;
const int nfrags = skb_shinfo(skb)->nr_frags;
+ const int dmabuf = skb->dmabuf;
skb_shinfo(skb)->nr_frags = 0;
skb1->len = skb1->data_len = skb->len - len;
@@ -3949,6 +3979,16 @@ static inline void skb_split_no_header(struct sk_buff *skb,
pos += size;
}
skb_shinfo(skb1)->nr_frags = k;
+
+ if (skb_shinfo(skb)->nr_frags)
+ skb->dmabuf = dmabuf;
+ else
+ skb->dmabuf = 0;
+
+ if (skb_shinfo(skb1)->nr_frags)
+ skb1->dmabuf = dmabuf;
+ else
+ skb1->dmabuf = 0;
}
/**
@@ -4184,6 +4224,9 @@ unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
return block_limit - abs_offset;
}
+ if (!skb_frags_readable(st->cur_skb))
+ return 0;
+
if (st->frag_idx == 0 && !st->frag_data)
st->stepped_offset += skb_headlen(st->cur_skb);
@@ -5799,7 +5842,10 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
(from->pp_recycle && skb_cloned(from)))
return false;
- if (len <= skb_tailroom(to)) {
+ if (skb_frags_readable(from) != skb_frags_readable(to))
+ return false;
+
+ if (len <= skb_tailroom(to) && skb_frags_readable(from)) {
if (len)
BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len));
*delta_truesize = 0;
@@ -5974,6 +6020,9 @@ int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len)
if (!pskb_may_pull(skb, write_len))
return -ENOMEM;
+ if (!skb_frags_readable(skb))
+ return -EFAULT;
+
if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
return 0;
@@ -6628,7 +6677,7 @@ void skb_condense(struct sk_buff *skb)
{
if (skb->data_len) {
if (skb->data_len > skb->end - skb->tail ||
- skb_cloned(skb))
+ skb_cloned(skb) || !skb_frags_readable(skb))
return;
/* Nice, we can free page frag(s) right now */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 82485af12cdc..6f4c59143156 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2140,6 +2140,9 @@ static int tcp_zerocopy_receive(struct sock *sk,
skb = tcp_recv_skb(sk, seq, &offset);
}
+ if (!skb_frags_readable(skb))
+ break;
+
if (TCP_SKB_CB(skb)->has_rxtstamp) {
tcp_update_recv_tstamps(skb, tss);
zc->msg_flags |= TCP_CMSG_TS;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index df7b13f0e5e0..1964459d722a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5331,6 +5331,9 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
for (end_of_skbs = true; skb != NULL && skb != tail; skb = n) {
n = tcp_skb_next(skb, list);
+ if (!skb_frags_readable(skb))
+ goto skip_this;
+
/* No new bits? It is possible on ofo queue. */
if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
skb = tcp_collapse_one(sk, skb, list, root);
@@ -5351,17 +5354,20 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
break;
}
- if (n && n != tail && mptcp_skb_can_collapse(skb, n) &&
+ if (n && n != tail && skb_frags_readable(n) &&
+ mptcp_skb_can_collapse(skb, n) &&
TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(n)->seq) {
end_of_skbs = false;
break;
}
+skip_this:
/* Decided to skip this, advance start seq. */
start = TCP_SKB_CB(skb)->end_seq;
}
if (end_of_skbs ||
- (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)))
+ (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)) ||
+ !skb_frags_readable(skb))
return;
__skb_queue_head_init(&tmp);
@@ -5405,7 +5411,8 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
if (!skb ||
skb == tail ||
!mptcp_skb_can_collapse(nskb, skb) ||
- (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)))
+ (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)) ||
+ !skb_frags_readable(skb))
goto end;
#ifdef CONFIG_TLS_DEVICE
if (skb->decrypted != nskb->decrypted)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e3167ad96567..30f53de14a24 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2343,7 +2343,8 @@ static bool tcp_can_coalesce_send_queue_head(struct sock *sk, int len)
if (unlikely(TCP_SKB_CB(skb)->eor) ||
tcp_has_tx_tstamp(skb) ||
- !skb_pure_zcopy_same(skb, next))
+ !skb_pure_zcopy_same(skb, next) ||
+ skb_frags_readable(skb) != skb_frags_readable(next))
return false;
len -= skb->len;
@@ -3227,6 +3228,8 @@ static bool tcp_can_collapse(const struct sock *sk, const struct sk_buff *skb)
return false;
if (skb_cloned(skb))
return false;
+ if (!skb_frags_readable(skb))
+ return false;
/* Some heuristics for collapsing over SACK'd could be invented */
if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
return false;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 5f1757a32842..bfed83ef92ef 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2156,7 +2156,7 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
}
}
- snaplen = skb->len;
+ snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb);
res = run_filter(skb, sk, snaplen);
if (!res)
@@ -2276,7 +2276,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
}
}
- snaplen = skb->len;
+ snaplen = skb_frags_readable(skb) ? skb->len : skb_headlen(skb);
res = run_filter(skb, sk, snaplen);
if (!res)
--
2.43.0.472.g3155946c3a-goog
In tcp_recvmsg_locked(), detect if the skb being received by the user
is a devmem skb. In this case - if the user provided the MSG_SOCK_DEVMEM
flag - pass it to tcp_recvmsg_devmem() for custom handling.
tcp_recvmsg_devmem() copies any data in the skb header to the linear
buffer, and returns a cmsg to the user indicating the number of bytes
returned in the linear buffer.
tcp_recvmsg_devmem() then loops over the unaccessible devmem skb frags,
and returns to the user a cmsg_devmem indicating the location of the
data in the dmabuf device memory. cmsg_devmem contains this information:
1. the offset into the dmabuf where the payload starts. 'frag_offset'.
2. the size of the frag. 'frag_size'.
3. an opaque token 'frag_token' to return to the kernel when the buffer
is to be released.
The pages awaiting freeing are stored in the newly added
sk->sk_user_frags, and each page passed to userspace is get_page()'d.
This reference is dropped once the userspace indicates that it is
done reading this page. All pages are released when the socket is
destroyed.
Signed-off-by: Willem de Bruijn <[email protected]>
Signed-off-by: Kaiyuan Zhang <[email protected]>
Signed-off-by: Mina Almasry <[email protected]>
---
Changes in v1:
- Added dmabuf_id to dmabuf_cmsg (David/Stan).
- Devmem -> dmabuf (David).
- Change tcp_recvmsg_dmabuf() check to skb->dmabuf (Paolo).
- Use __skb_frag_ref() & napi_pp_put_page() for refcounting (Yunsheng).
RFC v3:
- Fixed issue with put_cmsg() failing silently.
---
include/linux/socket.h | 1 +
include/net/netmem.h | 13 ++
include/net/sock.h | 2 +
include/uapi/asm-generic/socket.h | 5 +
include/uapi/linux/uio.h | 10 ++
net/ipv4/tcp.c | 190 +++++++++++++++++++++++++++++-
net/ipv4/tcp_ipv4.c | 9 ++
7 files changed, 225 insertions(+), 5 deletions(-)
diff --git a/include/linux/socket.h b/include/linux/socket.h
index cfcb7e2c3813..fe2b9e2081bb 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -326,6 +326,7 @@ struct ucred {
* plain text and require encryption
*/
+#define MSG_SOCK_DEVMEM 0x2000000 /* Receive devmem skbs as cmsg */
#define MSG_ZEROCOPY 0x4000000 /* Use user data in kernel path */
#define MSG_SPLICE_PAGES 0x8000000 /* Splice the pages from the iterator in sendmsg() */
#define MSG_FASTOPEN 0x20000000 /* Send data in TCP SYN */
diff --git a/include/net/netmem.h b/include/net/netmem.h
index ab3824b7b789..fa6d7b7ddef9 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -64,6 +64,19 @@ static inline unsigned int net_iov_idx(const struct net_iov *niov)
return niov - net_iov_owner(niov)->niovs;
}
+static inline unsigned long net_iov_virtual_addr(const struct net_iov *niov)
+{
+ struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov);
+
+ return owner->base_virtual +
+ ((unsigned long)net_iov_idx(niov) << PAGE_SHIFT);
+}
+
+static inline u32 net_iov_binding_id(const struct net_iov *niov)
+{
+ return net_iov_owner(niov)->binding->id;
+}
+
static inline dma_addr_t net_iov_dma_addr(const struct net_iov *niov)
{
struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov);
diff --git a/include/net/sock.h b/include/net/sock.h
index 8b6fe164b218..8eccf6ed8eb1 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -353,6 +353,7 @@ struct sk_filter;
* @sk_txtime_unused: unused txtime flags
* @ns_tracker: tracker for netns reference
* @sk_bind2_node: bind node in the bhash2 table
+ * @sk_user_frags: xarray of pages the user is holding a reference on.
*/
struct sock {
/*
@@ -545,6 +546,7 @@ struct sock {
struct rcu_head sk_rcu;
netns_tracker ns_tracker;
struct hlist_node sk_bind2_node;
+ struct xarray sk_user_frags;
};
enum sk_pacing {
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 8ce8a39a1e5f..25a2f5255f52 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -135,6 +135,11 @@
#define SO_PASSPIDFD 76
#define SO_PEERPIDFD 77
+#define SO_DEVMEM_LINEAR 98
+#define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR
+#define SO_DEVMEM_DMABUF 99
+#define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
diff --git a/include/uapi/linux/uio.h b/include/uapi/linux/uio.h
index 059b1a9147f4..ad92e37699da 100644
--- a/include/uapi/linux/uio.h
+++ b/include/uapi/linux/uio.h
@@ -20,6 +20,16 @@ struct iovec
__kernel_size_t iov_len; /* Must be size_t (1003.1g) */
};
+struct dmabuf_cmsg {
+ __u64 frag_offset; /* offset into the dmabuf where the frag starts.
+ */
+ __u32 frag_size; /* size of the frag. */
+ __u32 frag_token; /* token representing this frag for
+ * DEVMEM_DONTNEED.
+ */
+ __u32 dmabuf_id; /* dmabuf id this frag belongs to. */
+};
+
/*
* UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1)
*/
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 6f4c59143156..9df4f512d841 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -461,6 +461,7 @@ void tcp_init_sock(struct sock *sk)
set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
sk_sockets_allocated_inc(sk);
+ xa_init_flags(&sk->sk_user_frags, XA_FLAGS_ALLOC1);
}
EXPORT_SYMBOL(tcp_init_sock);
@@ -2303,6 +2304,155 @@ static int tcp_inq_hint(struct sock *sk)
return inq;
}
+/* On error, returns the -errno. On success, returns number of bytes sent to the
+ * user. May not consume all of @remaining_len.
+ */
+static int tcp_recvmsg_dmabuf(const struct sock *sk, const struct sk_buff *skb,
+ unsigned int offset, struct msghdr *msg,
+ int remaining_len)
+{
+ struct dmabuf_cmsg dmabuf_cmsg = { 0 };
+ unsigned int start;
+ int i, copy, n;
+ int sent = 0;
+ int err = 0;
+
+ do {
+ start = skb_headlen(skb);
+
+ if (!skb->dmabuf) {
+ err = -ENODEV;
+ goto out;
+ }
+
+ /* Copy header. */
+ copy = start - offset;
+ if (copy > 0) {
+ copy = min(copy, remaining_len);
+
+ n = copy_to_iter(skb->data + offset, copy,
+ &msg->msg_iter);
+ if (n != copy) {
+ err = -EFAULT;
+ goto out;
+ }
+
+ offset += copy;
+ remaining_len -= copy;
+
+ /* First a dmabuf_cmsg for # bytes copied to user
+ * buffer.
+ */
+ memset(&dmabuf_cmsg, 0, sizeof(dmabuf_cmsg));
+ dmabuf_cmsg.frag_size = copy;
+ err = put_cmsg(msg, SOL_SOCKET, SO_DEVMEM_LINEAR,
+ sizeof(dmabuf_cmsg), &dmabuf_cmsg);
+ if (err || msg->msg_flags & MSG_CTRUNC) {
+ msg->msg_flags &= ~MSG_CTRUNC;
+ if (!err)
+ err = -ETOOSMALL;
+ goto out;
+ }
+
+ sent += copy;
+
+ if (remaining_len == 0)
+ goto out;
+ }
+
+ /* after that, send information of dmabuf pages through a
+ * sequence of cmsg
+ */
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+ struct net_iov *niov;
+ u64 frag_offset;
+ u32 user_token;
+ int end;
+
+ /* skb->dmabuf should indicate that ALL the frags in
+ * this skb are dmabuf net_iovs. We're checking
+ * for that flag above, but also check individual frags
+ * here. If the tcp stack is not setting skb->dmabuf
+ * correctly, we still don't want to crash here when
+ * accessing pgmap or priv below.
+ */
+ if (!skb_frag_net_iov(frag)) {
+ net_err_ratelimited("Found non-dmabuf skb with net_iov");
+ err = -ENODEV;
+ goto out;
+ }
+
+ niov = skb_frag_net_iov(frag);
+ end = start + skb_frag_size(frag);
+ copy = end - offset;
+
+ if (copy > 0) {
+ copy = min(copy, remaining_len);
+
+ frag_offset = net_iov_virtual_addr(niov) +
+ skb_frag_off(frag) + offset -
+ start;
+ dmabuf_cmsg.frag_offset = frag_offset;
+ dmabuf_cmsg.frag_size = copy;
+ err = xa_alloc((struct xarray *)&sk->sk_user_frags,
+ &user_token, frag->bv_page,
+ xa_limit_31b, GFP_KERNEL);
+ if (err)
+ goto out;
+
+ dmabuf_cmsg.frag_token = user_token;
+ dmabuf_cmsg.dmabuf_id = net_iov_binding_id(niov);
+
+ offset += copy;
+ remaining_len -= copy;
+
+ err = put_cmsg(msg, SOL_SOCKET,
+ SO_DEVMEM_DMABUF,
+ sizeof(dmabuf_cmsg),
+ &dmabuf_cmsg);
+ if (err || msg->msg_flags & MSG_CTRUNC) {
+ msg->msg_flags &= ~MSG_CTRUNC;
+ xa_erase((struct xarray *)&sk->sk_user_frags,
+ user_token);
+ if (!err)
+ err = -ETOOSMALL;
+ goto out;
+ }
+
+ atomic_long_inc(&niov->pp_ref_count);
+
+ sent += copy;
+
+ if (remaining_len == 0)
+ goto out;
+ }
+ start = end;
+ }
+
+ if (!remaining_len)
+ goto out;
+
+ /* if remaining_len is not satisfied yet, we need to go to the
+ * next frag in the frag_list to satisfy remaining_len.
+ */
+ skb = skb_shinfo(skb)->frag_list ?: skb->next;
+
+ offset = offset - start;
+ } while (skb);
+
+ if (remaining_len) {
+ err = -EFAULT;
+ goto out;
+ }
+
+out:
+ if (!sent)
+ sent = err;
+
+ return sent;
+}
+
/*
* This routine copies from a sock struct into the user buffer.
*
@@ -2316,6 +2466,7 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
int *cmsg_flags)
{
struct tcp_sock *tp = tcp_sk(sk);
+ int last_copied_dmabuf = -1; /* uninitialized */
int copied = 0;
u32 peek_seq;
u32 *seq;
@@ -2493,15 +2644,44 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
}
if (!(flags & MSG_TRUNC)) {
- err = skb_copy_datagram_msg(skb, offset, msg, used);
- if (err) {
- /* Exception. Bailout! */
- if (!copied)
- copied = -EFAULT;
+ if (last_copied_dmabuf != -1 &&
+ last_copied_dmabuf != skb->dmabuf)
break;
+
+ if (!skb->dmabuf) {
+ err = skb_copy_datagram_msg(skb, offset, msg,
+ used);
+ if (err) {
+ /* Exception. Bailout! */
+ if (!copied)
+ copied = -EFAULT;
+ break;
+ }
+ } else {
+ if (!(flags & MSG_SOCK_DEVMEM)) {
+ /* skb->dmabuf skbs can only be received
+ * with the MSG_SOCK_DEVMEM flag.
+ */
+ if (!copied)
+ copied = -EFAULT;
+
+ break;
+ }
+
+ err = tcp_recvmsg_dmabuf(sk, skb, offset, msg,
+ used);
+ if (err <= 0) {
+ if (!copied)
+ copied = -EFAULT;
+
+ break;
+ }
+ used = err;
}
}
+ last_copied_dmabuf = skb->dmabuf;
+
WRITE_ONCE(*seq, *seq + used);
copied += used;
len -= used;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 4bac6e319aca..bff35d9be076 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2501,6 +2501,15 @@ static void tcp_md5sig_info_free_rcu(struct rcu_head *head)
void tcp_v4_destroy_sock(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
+ __maybe_unused unsigned long index;
+ __maybe_unused struct netmem *netmem;
+
+#ifdef CONFIG_PAGE_POOL
+ xa_for_each(&sk->sk_user_frags, index, netmem)
+ WARN_ON_ONCE(!napi_pp_put_page(netmem, false));
+#endif
+
+ xa_destroy(&sk->sk_user_frags);
trace_tcp_destroy_sock(sk);
--
2.43.0.472.g3155946c3a-goog
Add an interface for the user to notify the kernel that it is done
reading the devmem dmabuf frags returned as cmsg. The kernel will
drop the reference on the frags to make them available for re-use.
Signed-off-by: Willem de Bruijn <[email protected]>
Signed-off-by: Kaiyuan Zhang <[email protected]>
Signed-off-by: Mina Almasry <[email protected]>
---
Changes in v1:
- devmemtoken -> dmabuf_token (David).
- Use napi_pp_put_page() for refcounting (Yunsheng).
- Fix build error with missing socket options on other asms.
---
arch/alpha/include/uapi/asm/socket.h | 8 ++++-
arch/mips/include/uapi/asm/socket.h | 6 ++++
arch/parisc/include/uapi/asm/socket.h | 6 ++++
arch/sparc/include/uapi/asm/socket.h | 6 ++++
include/uapi/asm-generic/socket.h | 1 +
include/uapi/linux/uio.h | 4 +++
net/core/sock.c | 45 +++++++++++++++++++++++++++
7 files changed, 75 insertions(+), 1 deletion(-)
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index e94f621903fe..00146c243037 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -10,7 +10,7 @@
* Note: we only bother about making the SOL_SOCKET options
* same as OSF/1, as that's all that "normal" programs are
* likely to set. We don't necessarily want to be binary
- * compatible with _everything_.
+ * compatible with _everything_.
*/
#define SOL_SOCKET 0xffff
@@ -140,6 +140,12 @@
#define SO_PASSPIDFD 76
#define SO_PEERPIDFD 77
+#define SO_DEVMEM_DONTNEED 78
+#define SO_DEVMEM_LINEAR 79
+#define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR
+#define SO_DEVMEM_DMABUF 80
+#define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index 60ebaed28a4c..9a71ee8f36db 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -151,6 +151,12 @@
#define SO_PASSPIDFD 76
#define SO_PEERPIDFD 77
+#define SO_DEVMEM_DONTNEED 78
+#define SO_DEVMEM_LINEAR 79
+#define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR
+#define SO_DEVMEM_DMABUF 80
+#define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index be264c2b1a11..6b8674399363 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -132,6 +132,12 @@
#define SO_PASSPIDFD 0x404A
#define SO_PEERPIDFD 0x404B
+#define SO_DEVMEM_DONTNEED 0x404C
+#define SO_DEVMEM_LINEAR 0x404D
+#define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR
+#define SO_DEVMEM_DMABUF 0x404E
+#define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 682da3714686..ecfc8bfa9fe0 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -133,6 +133,12 @@
#define SO_PASSPIDFD 0x0055
#define SO_PEERPIDFD 0x0056
+#define SO_DEVMEM_DONTNEED 0x0057
+#define SO_DEVMEM_LINEAR 0x0058
+#define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR
+#define SO_DEVMEM_DMABUF 0x0059
+#define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF
+
#if !defined(__KERNEL__)
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 25a2f5255f52..1acb77780f10 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -135,6 +135,7 @@
#define SO_PASSPIDFD 76
#define SO_PEERPIDFD 77
+#define SO_DEVMEM_DONTNEED 97
#define SO_DEVMEM_LINEAR 98
#define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR
#define SO_DEVMEM_DMABUF 99
diff --git a/include/uapi/linux/uio.h b/include/uapi/linux/uio.h
index ad92e37699da..65f33178a601 100644
--- a/include/uapi/linux/uio.h
+++ b/include/uapi/linux/uio.h
@@ -30,6 +30,10 @@ struct dmabuf_cmsg {
__u32 dmabuf_id; /* dmabuf id this frag belongs to. */
};
+struct dmabuf_token {
+ __u32 token_start;
+ __u32 token_count;
+};
/*
* UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1)
*/
diff --git a/net/core/sock.c b/net/core/sock.c
index 446e945f736b..77497dbb9022 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1047,6 +1047,46 @@ static int sock_reserve_memory(struct sock *sk, int bytes)
return 0;
}
+#ifdef CONFIG_PAGE_POOL
+static noinline_for_stack int
+sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen)
+{
+ unsigned int num_tokens, i, j;
+ struct dmabuf_token *tokens;
+ int ret;
+
+ if (sk->sk_type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP)
+ return -EBADF;
+
+ if (optlen % sizeof(struct dmabuf_token) || optlen > sizeof(*tokens) * 128)
+ return -EINVAL;
+
+ tokens = kvmalloc_array(128, sizeof(*tokens), GFP_KERNEL);
+ if (!tokens)
+ return -ENOMEM;
+
+ num_tokens = optlen / sizeof(struct dmabuf_token);
+ if (copy_from_sockptr(tokens, optval, optlen))
+ return -EFAULT;
+
+ ret = 0;
+ for (i = 0; i < num_tokens; i++) {
+ for (j = 0; j < tokens[i].token_count; j++) {
+ struct netmem *netmem = xa_erase(&sk->sk_user_frags,
+ tokens[i].token_start + j);
+
+ if (netmem && !WARN_ON_ONCE(!netmem_is_net_iov(netmem))) {
+ WARN_ON_ONCE(!napi_pp_put_page(netmem, false));
+ ret++;
+ }
+ }
+ }
+
+ kvfree(tokens);
+ return ret;
+}
+#endif
+
void sockopt_lock_sock(struct sock *sk)
{
/* When current->bpf_ctx is set, the setsockopt is called from
@@ -1534,6 +1574,11 @@ int sk_setsockopt(struct sock *sk, int level, int optname,
break;
}
+#ifdef CONFIG_PAGE_POOL
+ case SO_DEVMEM_DONTNEED:
+ ret = sock_devmem_dontneed(sk, optval, optlen);
+ break;
+#endif
default:
ret = -ENOPROTOOPT;
break;
--
2.43.0.472.g3155946c3a-goog
Signed-off-by: Mina Almasry <[email protected]>
---
v1 -> v2:
- Missing spdx (simon)
- add to index.rst (simon)
---
Documentation/networking/devmem.rst | 271 ++++++++++++++++++++++++++++
Documentation/networking/index.rst | 1 +
2 files changed, 272 insertions(+)
create mode 100644 Documentation/networking/devmem.rst
diff --git a/Documentation/networking/devmem.rst b/Documentation/networking/devmem.rst
new file mode 100644
index 000000000000..4712f029e5ed
--- /dev/null
+++ b/Documentation/networking/devmem.rst
@@ -0,0 +1,271 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+Device Memory TCP
+=================
+
+
+Intro
+=====
+
+Device memory TCP (devmem TCP) enables receiving data directly into device
+memory (dmabuf). The feature is currently implemented for TCP sockets.
+
+
+Opportunity
+-----------
+
+A large amount of data transfers have device memory as the source and/or
+destination. Accelerators drastically increased the volume of such transfers.
+Some examples include:
+
+- Distributed training, where ML accelerators, such as GPUs on different hosts,
+ exchange data among them.
+
+- Distributed raw block storage applications transfer large amounts of data with
+ remote SSDs, much of this data does not require host processing.
+
+Today, the majority of the Device-to-Device data transfers the network are
+implemented as the following low level operations: Device-to-Host copy,
+Host-to-Host network transfer, and Host-to-Device copy.
+
+The implementation is suboptimal, especially for bulk data transfers, and can
+put significant strains on system resources such as host memory bandwidth and
+PCIe bandwidth.
+
+Devmem TCP optimizes this use case by implementing socket APIs that enable
+the user to receive incoming network packets directly into device memory.
+
+Packet payloads go directly from the NIC to device memory.
+
+Packet headers go to host memory and are processed by the TCP/IP stack
+normally. The NIC must support header split to achieve this.
+
+Advantages:
+
+- Alleviate host memory bandwidth pressure, compared to existing
+ network-transfer + device-copy semantics.
+
+- Alleviate PCIe bandwidth pressure, by limiting data transfer to the lowest
+ level of the PCIe tree, compared to traditional path which sends data through
+ the root complex.
+
+
+More Info
+---------
+
+ slides, video
+ https://netdevconf.org/0x17/sessions/talk/device-memory-tcp.html
+
+ patchset
+ [RFC PATCH v3 00/12] Device Memory TCP
+ https://lore.kernel.org/lkml/[email protected]/T/
+
+
+Interface
+=========
+
+Example
+-------
+
+tools/testing/selftests/net/ncdevmem.c:do_server shows an example of setting up
+the RX path of this API.
+
+NIC Setup
+---------
+
+Header split, flow steering, & RSS are required features for devmem TCP.
+
+Header split is used to split incoming packets into a header buffer in host
+memory, and a payload buffer in device memory.
+
+Flow steering & RSS are used to ensure that only flows targeting devmem land on
+RX queue bound to devmem.
+
+Enable header split & flow steering:
+
+::
+
+ # enable header split (assuming priv-flag)
+ ethtool --set-priv-flags eth1 enable-header-split on
+
+ # enable flow steering
+ ethtool -K eth1 ntuple on
+
+Configure RSS to steer all traffic away from the target RX queue (queue 15 in
+this example):
+
+::
+
+ ethtool --set-rxfh-indir eth1 equal 15
+
+
+The user must bind a dmabuf to any number of RX queues on a given NIC using
+netlink API:
+
+::
+
+ /* Bind dmabuf to NIC RX queue 15 */
+ struct netdev_queue *queues;
+ queues = malloc(sizeof(*queues) * 1);
+
+ queues[0]._present.type = 1;
+ queues[0]._present.idx = 1;
+ queues[0].type = NETDEV_RX_QUEUE_TYPE_RX;
+ queues[0].idx = 15;
+
+ *ys = ynl_sock_create(&ynl_netdev_family, &yerr);
+
+ req = netdev_bind_rx_req_alloc();
+ netdev_bind_rx_req_set_ifindex(req, 1 /* ifindex */);
+ netdev_bind_rx_req_set_dmabuf_fd(req, dmabuf_fd);
+ __netdev_bind_rx_req_set_queues(req, queues, n_queue_index);
+
+ rsp = netdev_bind_rx(*ys, req);
+
+ dmabuf_id = rsp->dmabuf_id;
+
+
+The netlink API returns a dmabuf_id: a unique ID that refers to this dmabuf
+that has been bound.
+
+Socket Setup
+------------
+
+The socket must be flow steering to the dmabuf bound RX queue:
+
+::
+
+ ethtool -N eth1 flow-type tcp4 ... queue 15,
+
+
+Receiving data
+--------------
+
+The user application must signal to the kernel that it is capable of receiving
+devmem data by passing the MSG_SOCK_DEVMEM flag to recvmsg:
+
+::
+
+ ret = recvmsg(fd, &msg, MSG_SOCK_DEVMEM);
+
+Applications that do not specify the MSG_SOCK_DEVMEM flag will receive an EFAULT
+on devmem data.
+
+Devmem data is received directly into the dmabuf bound to the NIC in 'NIC
+Setup', and the kernel signals such to the user via the SCM_DEVMEM_* cmsgs:
+
+::
+
+ for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm)) {
+ if (cm->cmsg_level != SOL_SOCKET ||
+ (cm->cmsg_type != SCM_DEVMEM_DMABUF &&
+ cm->cmsg_type != SCM_DEVMEM_LINEAR))
+ continue;
+
+ dmabuf_cmsg = (struct dmabuf_cmsg *)CMSG_DATA(cm);
+
+ if (cm->cmsg_type == SCM_DEVMEM_DMABUF) {
+ /* Frag landed in dmabuf.
+ *
+ * dmabuf_cmsg->dmabuf_id is the dmabuf the
+ * frag landed on.
+ *
+ * dmabuf_cmsg->frag_offset is the offset into
+ * the dmabuf where the frag starts.
+ *
+ * dmabuf_cmsg->frag_size is the size of the
+ * frag.
+ *
+ * dmabuf_cmsg->frag_token is a token used to
+ * refer to this frag for later freeing.
+ */
+
+ struct dmabuf_token token;
+ token.token_start = dmabuf_cmsg->frag_token;
+ token.token_count = 1;
+ continue;
+ }
+
+ if (cm->cmsg_type == SCM_DEVMEM_LINEAR)
+ /* Frag landed in linear buffer.
+ *
+ * dmabuf_cmsg->frag_size is the size of the
+ * frag.
+ */
+ continue;
+
+ }
+
+Applications may receive 2 cmsgs:
+
+- SCM_DEVMEM_DMABUF: this indicates the fragment landed in the dmabuf indicated
+ by dmabuf_id.
+
+- SCM_DEVMEM_LINEAR: this indicates the fragment landed in the linear buffer.
+ This typically happens when the NIC is unable to split the packet at the
+ header boundary, such that part (or all) of the payload landed in host
+ memory.
+
+Applications may receive no SO_DEVMEM_* cmsgs. That indicates non-devmem,
+regular TCP data that landed on an RX queue not bound to a dmabuf.
+
+
+Freeing frags
+-------------
+
+Frags received via SCM_DEVMEM_DMABUF are pinned by the kernel while the user
+processes the frag. The user must return the frag to the kernel via
+SO_DEVMEM_DONTNEED:
+
+::
+
+ ret = setsockopt(client_fd, SOL_SOCKET, SO_DEVMEM_DONTNEED, &token,
+ sizeof(token));
+
+The user must ensure the tokens are returned to the kernel in a timely manner.
+Failure to do so will exhaust the limited dmabuf that is bound to the RX queue
+and will lead to packet drops.
+
+
+Implementation & Caveats
+========================
+
+Unreadable skbs
+---------------
+
+Devmem payloads are inaccessible to the kernel processing the packets. This
+results in a few quirks for payloads of devmem skbs:
+
+- Loopback is not functional. Loopback relies on copying the payload, which is
+ not possible with devmem skbs.
+
+- Software checksum calculation fails.
+
+- TCP Dump and bpf can't access devmem packet payloads.
+
+
+Testing
+=======
+
+More realistic example code can be found in the kernel source under
+tools/testing/selftests/net/ncdevmem.c
+
+ncdevmem is a devmem TCP netcat. It works very similarly to netcat, but
+receives data directly into a udmabuf.
+
+To run ncdevmem, you need to run it a server on the machine under test, and you
+need to run netcat on a peer to provide the TX data.
+
+ncdevmem has a validation mode as well that expects a repeating pattern of
+incoming data and validates it as such:
+
+::
+
+ # On server:
+ ncdevmem -s <server IP> -c <client IP> -f eth1 -d 3 -n 0000:06:00.0 -l \
+ -p 5201 -v 7
+
+ # On client:
+ yes $(echo -e \\x01\\x02\\x03\\x04\\x05\\x06) | \
+ tr \\n \\0 | head -c 5G | nc <server IP> 5201 -p 5201
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index 69f3d6dcd9fd..d9f86514aa1e 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -48,6 +48,7 @@ Contents:
cdc_mbim
dccp
dctcp
+ devmem
dns_resolver
driver
eql
--
2.43.0.472.g3155946c3a-goog
ncdevmem is a devmem TCP netcat. It works similarly to netcat, but it
sends and receives data using the devmem TCP APIs. It uses udmabuf as
the dmabuf provider. It is compatible with a regular netcat running on
a peer, or a ncdevmem running on a peer.
In addition to normal netcat support, ncdevmem has a validation mode,
where it sends a specific pattern and validates this pattern on the
receiver side to ensure data integrity.
Suggested-by: Stanislav Fomichev <[email protected]>
Signed-off-by: Mina Almasry <[email protected]>
---
Changes in v1:
- Many more general cleanups (Willem).
- Removed driver reset (Jakub).
- Removed hardcoded if index (Paolo).
RFC v2:
- General cleanups (Willem).
---
tools/testing/selftests/net/.gitignore | 1 +
tools/testing/selftests/net/Makefile | 5 +
tools/testing/selftests/net/ncdevmem.c | 489 +++++++++++++++++++++++++
3 files changed, 495 insertions(+)
create mode 100644 tools/testing/selftests/net/ncdevmem.c
diff --git a/tools/testing/selftests/net/.gitignore b/tools/testing/selftests/net/.gitignore
index 2f9d378edec3..b644dbae58b7 100644
--- a/tools/testing/selftests/net/.gitignore
+++ b/tools/testing/selftests/net/.gitignore
@@ -17,6 +17,7 @@ ipv6_flowlabel
ipv6_flowlabel_mgr
log.txt
msg_zerocopy
+ncdevmem
nettest
psock_fanout
psock_snd
diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 14bd68da7466..d7a66563ffe7 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -5,6 +5,10 @@ CFLAGS = -Wall -Wl,--no-as-needed -O2 -g
CFLAGS += -I../../../../usr/include/ $(KHDR_INCLUDES)
# Additional include paths needed by kselftest.h
CFLAGS += -I../
+CFLAGS += -I../../../net/ynl/generated/
+CFLAGS += -I../../../net/ynl/lib/
+
+LDLIBS += ../../../net/ynl/lib/ynl.a ../../../net/ynl/generated/protos.a
TEST_PROGS := run_netsocktests run_afpackettests test_bpf.sh netdevice.sh \
rtnetlink.sh xfrm_policy.sh test_blackhole_dev.sh
@@ -92,6 +96,7 @@ TEST_PROGS += test_vxlan_nolocalbypass.sh
TEST_PROGS += test_bridge_backup_port.sh
TEST_PROGS += fdb_flush.sh
TEST_PROGS += fq_band_pktlimit.sh
+TEST_GEN_FILES += ncdevmem
TEST_FILES := settings
diff --git a/tools/testing/selftests/net/ncdevmem.c b/tools/testing/selftests/net/ncdevmem.c
new file mode 100644
index 000000000000..7fbeee02b9a2
--- /dev/null
+++ b/tools/testing/selftests/net/ncdevmem.c
@@ -0,0 +1,489 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#define __EXPORTED_HEADERS__
+
+#include <linux/uio.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <string.h>
+#include <errno.h>
+#define __iovec_defined
+#include <fcntl.h>
+#include <malloc.h>
+#include <error.h>
+
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+
+#include <linux/memfd.h>
+#include <linux/if.h>
+#include <linux/dma-buf.h>
+#include <linux/udmabuf.h>
+#include <libmnl/libmnl.h>
+#include <linux/types.h>
+#include <linux/netlink.h>
+#include <linux/genetlink.h>
+#include <linux/netdev.h>
+#include <time.h>
+
+#include "netdev-user.h"
+#include <ynl.h>
+
+#define PAGE_SHIFT 12
+#define TEST_PREFIX "ncdevmem"
+#define NUM_PAGES 16000
+
+#ifndef MSG_SOCK_DEVMEM
+#define MSG_SOCK_DEVMEM 0x2000000
+#endif
+
+/*
+ * tcpdevmem netcat. Works similarly to netcat but does device memory TCP
+ * instead of regular TCP. Uses udmabuf to mock a dmabuf provider.
+ *
+ * Usage:
+ *
+ * On server:
+ * ncdevmem -s <server IP> -c <client IP> -f eth1 -d 3 -n 0000:06:00.0 -l \
+ * -p 5201 -v 7
+ *
+ * On client:
+ * yes $(echo -e \\x01\\x02\\x03\\x04\\x05\\x06) | \
+ * tr \\n \\0 | \
+ * head -c 5G | \
+ * nc <server IP> 5201 -p 5201
+ *
+ * Note this is compatible with regular netcat. i.e. the sender or receiver can
+ * be replaced with regular netcat to test the RX or TX path in isolation.
+ */
+
+static char *server_ip = "192.168.1.4";
+static char *client_ip = "192.168.1.2";
+static char *port = "5201";
+static size_t do_validation;
+static int queue_num = 15;
+static char *ifname = "eth1";
+static unsigned int ifindex = 3;
+static char *nic_pci_addr = "0000:06:00.0";
+static unsigned int iterations;
+static unsigned int dmabuf_id;
+
+void print_bytes(void *ptr, size_t size)
+{
+ unsigned char *p = ptr;
+ int i;
+
+ for (i = 0; i < size; i++)
+ printf("%02hhX ", p[i]);
+ printf("\n");
+}
+
+void print_nonzero_bytes(void *ptr, size_t size)
+{
+ unsigned char *p = ptr;
+ unsigned int i;
+
+ for (i = 0; i < size; i++)
+ putchar(p[i]);
+ printf("\n");
+}
+
+void validate_buffer(void *line, size_t size)
+{
+ static unsigned char seed = 1;
+ unsigned char *ptr = line;
+ int errors = 0;
+ size_t i;
+
+ for (i = 0; i < size; i++) {
+ if (ptr[i] != seed) {
+ fprintf(stderr,
+ "Failed validation: expected=%u, actual=%u, index=%lu\n",
+ seed, ptr[i], i);
+ errors++;
+ if (errors > 20)
+ error(1, 0, "validation failed.");
+ }
+ seed++;
+ if (seed == do_validation)
+ seed = 0;
+ }
+
+ fprintf(stdout, "Validated buffer\n");
+}
+
+static void reset_flow_steering(void)
+{
+ char command[256];
+
+ memset(command, 0, sizeof(command));
+ snprintf(command, sizeof(command), "sudo ethtool -K %s ntuple off",
+ "eth1");
+ system(command);
+
+ memset(command, 0, sizeof(command));
+ snprintf(command, sizeof(command), "sudo ethtool -K %s ntuple on",
+ "eth1");
+ system(command);
+}
+
+static void configure_flow_steering(void)
+{
+ char command[256];
+
+ memset(command, 0, sizeof(command));
+ snprintf(command, sizeof(command),
+ "sudo ethtool -N %s flow-type tcp4 src-ip %s dst-ip %s src-port %s dst-port %s queue %d",
+ ifname, client_ip, server_ip, port, port, queue_num);
+ system(command);
+}
+
+static int bind_rx_queue(unsigned int ifindex, unsigned int dmabuf_fd,
+ struct netdev_queue_dmabuf *queues,
+ unsigned int n_queue_index, struct ynl_sock **ys)
+{
+ struct netdev_bind_rx_req *req = NULL;
+ struct netdev_bind_rx_rsp *rsp = NULL;
+ struct ynl_error yerr;
+
+ *ys = ynl_sock_create(&ynl_netdev_family, &yerr);
+ if (!*ys) {
+ fprintf(stderr, "YNL: %s\n", yerr.msg);
+ return -1;
+ }
+
+ req = netdev_bind_rx_req_alloc();
+ netdev_bind_rx_req_set_ifindex(req, ifindex);
+ netdev_bind_rx_req_set_dmabuf_fd(req, dmabuf_fd);
+ __netdev_bind_rx_req_set_queues(req, queues, n_queue_index);
+
+ rsp = netdev_bind_rx(*ys, req);
+ if (!rsp) {
+ perror("netdev_bind_rx");
+ goto err_close;
+ }
+
+ if (!rsp->_present.dmabuf_id) {
+ perror("dmabuf_id not present");
+ goto err_close;
+ }
+
+ printf("got dmabuf id=%d\n", rsp->dmabuf_id);
+ dmabuf_id = rsp->dmabuf_id;
+
+ netdev_bind_rx_req_free(req);
+ netdev_bind_rx_rsp_free(rsp);
+
+ return 0;
+
+err_close:
+ fprintf(stderr, "YNL failed: %s\n", (*ys)->err.msg);
+ netdev_bind_rx_req_free(req);
+ ynl_sock_destroy(*ys);
+ return -1;
+}
+
+static void create_udmabuf(int *devfd, int *memfd, int *buf, size_t dmabuf_size)
+{
+ struct udmabuf_create create;
+ int ret;
+
+ *devfd = open("/dev/udmabuf", O_RDWR);
+ if (*devfd < 0) {
+ error(70, 0,
+ "%s: [skip,no-udmabuf: Unable to access DMA buffer device file]\n",
+ TEST_PREFIX);
+ }
+
+ *memfd = memfd_create("udmabuf-test", MFD_ALLOW_SEALING);
+ if (*memfd < 0)
+ error(70, 0, "%s: [skip,no-memfd]\n", TEST_PREFIX);
+
+ /* Required for udmabuf */
+ ret = fcntl(*memfd, F_ADD_SEALS, F_SEAL_SHRINK);
+ if (ret < 0)
+ error(73, 0, "%s: [skip,fcntl-add-seals]\n", TEST_PREFIX);
+
+ ret = ftruncate(*memfd, dmabuf_size);
+ if (ret == -1)
+ error(74, 0, "%s: [FAIL,memfd-truncate]\n", TEST_PREFIX);
+
+ memset(&create, 0, sizeof(create));
+
+ create.memfd = *memfd;
+ create.offset = 0;
+ create.size = dmabuf_size;
+ *buf = ioctl(*devfd, UDMABUF_CREATE, &create);
+ if (*buf < 0)
+ error(75, 0, "%s: [FAIL, create udmabuf]\n", TEST_PREFIX);
+}
+
+int do_server(void)
+{
+ char ctrl_data[sizeof(int) * 20000];
+ struct netdev_queue_dmabuf *queues;
+ size_t non_page_aligned_frags = 0;
+ struct sockaddr_in client_addr;
+ struct sockaddr_in server_sin;
+ size_t page_aligned_frags = 0;
+ int devfd, memfd, buf, ret;
+ size_t total_received = 0;
+ socklen_t client_addr_len;
+ bool is_devmem = false;
+ char *buf_mem = NULL;
+ struct ynl_sock *ys;
+ size_t dmabuf_size;
+ char iobuf[819200];
+ char buffer[256];
+ int socket_fd;
+ int client_fd;
+ size_t i = 0;
+ int opt = 1;
+
+ dmabuf_size = getpagesize() * NUM_PAGES;
+
+ create_udmabuf(&devfd, &memfd, &buf, dmabuf_size);
+
+ reset_flow_steering();
+ configure_flow_steering();
+
+ sleep(1);
+
+ queues = malloc(sizeof(*queues) * 1);
+
+ queues[0]._present.type = 1;
+ queues[0]._present.idx = 1;
+ queues[0].type = NETDEV_QUEUE_TYPE_RX;
+ queues[0].idx = queue_num;
+ if (bind_rx_queue(ifindex, buf, queues, 1, &ys))
+ error(1, 0, "Failed to bind\n");
+
+ buf_mem = mmap(NULL, dmabuf_size, PROT_READ | PROT_WRITE, MAP_SHARED,
+ buf, 0);
+ if (buf_mem == MAP_FAILED)
+ error(1, 0, "mmap()");
+
+ server_sin.sin_family = AF_INET;
+ server_sin.sin_port = htons(atoi(port));
+
+ ret = inet_pton(server_sin.sin_family, server_ip, &server_sin.sin_addr);
+ if (socket < 0)
+ error(79, 0, "%s: [FAIL, create socket]\n", TEST_PREFIX);
+
+ socket_fd = socket(server_sin.sin_family, SOCK_STREAM, 0);
+ if (socket < 0)
+ error(errno, errno, "%s: [FAIL, create socket]\n", TEST_PREFIX);
+
+ ret = setsockopt(socket_fd, SOL_SOCKET, SO_REUSEPORT, &opt,
+ sizeof(opt));
+ if (ret)
+ error(errno, errno, "%s: [FAIL, set sock opt]\n", TEST_PREFIX);
+
+ ret = setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &opt,
+ sizeof(opt));
+ if (ret)
+ error(errno, errno, "%s: [FAIL, set sock opt]\n", TEST_PREFIX);
+
+ printf("binding to address %s:%d\n", server_ip,
+ ntohs(server_sin.sin_port));
+
+ ret = bind(socket_fd, &server_sin, sizeof(server_sin));
+ if (ret)
+ error(errno, errno, "%s: [FAIL, bind]\n", TEST_PREFIX);
+
+ ret = listen(socket_fd, 1);
+ if (ret)
+ error(errno, errno, "%s: [FAIL, listen]\n", TEST_PREFIX);
+
+ client_addr_len = sizeof(client_addr);
+
+ inet_ntop(server_sin.sin_family, &server_sin.sin_addr, buffer,
+ sizeof(buffer));
+ printf("Waiting or connection on %s:%d\n", buffer,
+ ntohs(server_sin.sin_port));
+ client_fd = accept(socket_fd, &client_addr, &client_addr_len);
+
+ inet_ntop(client_addr.sin_family, &client_addr.sin_addr, buffer,
+ sizeof(buffer));
+ printf("Got connection from %s:%d\n", buffer,
+ ntohs(client_addr.sin_port));
+
+ while (1) {
+ struct iovec iov = { .iov_base = iobuf,
+ .iov_len = sizeof(iobuf) };
+ struct dmabuf_cmsg *dmabuf_cmsg = NULL;
+ struct dma_buf_sync sync = { 0 };
+ struct cmsghdr *cm = NULL;
+ struct msghdr msg = { 0 };
+ struct dmabuf_token token;
+ ssize_t ret;
+
+ is_devmem = false;
+ printf("\n\n");
+
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+ msg.msg_control = ctrl_data;
+ msg.msg_controllen = sizeof(ctrl_data);
+ ret = recvmsg(client_fd, &msg, MSG_SOCK_DEVMEM);
+ printf("recvmsg ret=%ld\n", ret);
+ if (ret < 0 && (errno == EAGAIN || errno == EWOULDBLOCK))
+ continue;
+ if (ret < 0) {
+ perror("recvmsg");
+ continue;
+ }
+ if (ret == 0) {
+ printf("client exited\n");
+ goto cleanup;
+ }
+
+ i++;
+ for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm)) {
+ if (cm->cmsg_level != SOL_SOCKET ||
+ (cm->cmsg_type != SCM_DEVMEM_DMABUF &&
+ cm->cmsg_type != SCM_DEVMEM_LINEAR)) {
+ fprintf(stdout, "skipping non-devmem cmsg\n");
+ continue;
+ }
+
+ dmabuf_cmsg = (struct dmabuf_cmsg *)CMSG_DATA(cm);
+ is_devmem = true;
+
+ if (cm->cmsg_type == SCM_DEVMEM_LINEAR) {
+ /* TODO: process data copied from skb's linear
+ * buffer.
+ */
+ fprintf(stdout,
+ "SCM_DEVMEM_LINEAR. dmabuf_cmsg->frag_size=%u\n",
+ dmabuf_cmsg->frag_size);
+
+ continue;
+ }
+
+ token.token_start = dmabuf_cmsg->frag_token;
+ token.token_count = 1;
+
+ total_received += dmabuf_cmsg->frag_size;
+ printf("received frag_page=%llu, in_page_offset=%llu, frag_offset=%llu, frag_size=%u, token=%u, total_received=%lu, dmabuf_id=%u\n",
+ dmabuf_cmsg->frag_offset >> PAGE_SHIFT,
+ dmabuf_cmsg->frag_offset % getpagesize(),
+ dmabuf_cmsg->frag_offset, dmabuf_cmsg->frag_size,
+ dmabuf_cmsg->frag_token, total_received,
+ dmabuf_cmsg->dmabuf_id);
+
+ if (dmabuf_cmsg->dmabuf_id != dmabuf_id)
+ error(1, 0,
+ "received on wrong dmabuf_id: flow steering error\n");
+
+ if (dmabuf_cmsg->frag_size % getpagesize())
+ non_page_aligned_frags++;
+ else
+ page_aligned_frags++;
+
+ sync.flags = DMA_BUF_SYNC_READ | DMA_BUF_SYNC_START;
+ ioctl(buf, DMA_BUF_IOCTL_SYNC, &sync);
+
+ if (do_validation)
+ validate_buffer(
+ ((unsigned char *)buf_mem) +
+ dmabuf_cmsg->frag_offset,
+ dmabuf_cmsg->frag_size);
+ else
+ print_nonzero_bytes(
+ ((unsigned char *)buf_mem) +
+ dmabuf_cmsg->frag_offset,
+ dmabuf_cmsg->frag_size);
+
+ sync.flags = DMA_BUF_SYNC_READ | DMA_BUF_SYNC_END;
+ ioctl(buf, DMA_BUF_IOCTL_SYNC, &sync);
+
+ ret = setsockopt(client_fd, SOL_SOCKET,
+ SO_DEVMEM_DONTNEED, &token,
+ sizeof(token));
+ if (ret != 1)
+ error(1, 0,
+ "SO_DEVMEM_DONTNEED not enough tokens");
+ }
+ if (!is_devmem)
+ error(1, 0, "flow steering error\n");
+
+ printf("total_received=%lu\n", total_received);
+ }
+
+ fprintf(stdout, "%s: ok\n", TEST_PREFIX);
+
+ fprintf(stdout, "page_aligned_frags=%lu, non_page_aligned_frags=%lu\n",
+ page_aligned_frags, non_page_aligned_frags);
+
+ fprintf(stdout, "page_aligned_frags=%lu, non_page_aligned_frags=%lu\n",
+ page_aligned_frags, non_page_aligned_frags);
+
+cleanup:
+
+ munmap(buf_mem, dmabuf_size);
+ close(client_fd);
+ close(socket_fd);
+ close(buf);
+ close(memfd);
+ close(devfd);
+ ynl_sock_destroy(ys);
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ int is_server = 0, opt;
+
+ while ((opt = getopt(argc, argv, "ls:c:p:v:q:f:n:i:d:")) != -1) {
+ switch (opt) {
+ case 'l':
+ is_server = 1;
+ break;
+ case 's':
+ server_ip = optarg;
+ break;
+ case 'c':
+ client_ip = optarg;
+ break;
+ case 'p':
+ port = optarg;
+ break;
+ case 'v':
+ do_validation = atoll(optarg);
+ break;
+ case 'q':
+ queue_num = atoi(optarg);
+ break;
+ case 'f':
+ ifname = optarg;
+ break;
+ case 'd':
+ ifindex = atoi(optarg);
+ break;
+ case 'n':
+ nic_pci_addr = optarg;
+ break;
+ case 'i':
+ iterations = atoll(optarg);
+ break;
+ case '?':
+ printf("unknown option: %c\n", optopt);
+ break;
+ }
+ }
+
+ for (; optind < argc; optind++)
+ printf("extra arguments: %s\n", argv[optind]);
+
+ if (is_server)
+ return do_server();
+
+ return 0;
+}
--
2.43.0.472.g3155946c3a-goog
Hi Mina,
On 12/18/23 03:40, Mina Almasry wrote:
> Add an interface for the user to notify the kernel that it is done
> reading the devmem dmabuf frags returned as cmsg. The kernel will
> drop the reference on the frags to make them available for re-use.
>
> Signed-off-by: Willem de Bruijn <[email protected]>
> Signed-off-by: Kaiyuan Zhang <[email protected]>
> Signed-off-by: Mina Almasry <[email protected]>
>
> ---
>
> Changes in v1:
> - devmemtoken -> dmabuf_token (David).
> - Use napi_pp_put_page() for refcounting (Yunsheng).
> - Fix build error with missing socket options on other asms.
>
> ---
> arch/alpha/include/uapi/asm/socket.h | 8 ++++-
> arch/mips/include/uapi/asm/socket.h | 6 ++++
> arch/parisc/include/uapi/asm/socket.h | 6 ++++
> arch/sparc/include/uapi/asm/socket.h | 6 ++++
> include/uapi/asm-generic/socket.h | 1 +
> include/uapi/linux/uio.h | 4 +++
> net/core/sock.c | 45 +++++++++++++++++++++++++++
> 7 files changed, 75 insertions(+), 1 deletion(-)
>
...
> diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
> index be264c2b1a11..6b8674399363 100644
> --- a/arch/parisc/include/uapi/asm/socket.h
> +++ b/arch/parisc/include/uapi/asm/socket.h
> @@ -132,6 +132,12 @@
> #define SO_PASSPIDFD 0x404A
> #define SO_PEERPIDFD 0x404B
>
> +#define SO_DEVMEM_DONTNEED 0x404C
> +#define SO_DEVMEM_LINEAR 0x404D
> +#define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR
> +#define SO_DEVMEM_DMABUF 0x404E
> +#define SCM_DEVMEM_DMABUF SO_DEVMEM_DMABUF
Could you please change this ^^ for parisc to use the same constants as
the generic version below (97-99).
Although 0x404c is the logical successor, I'd prefer to be in sync
with other generic code if possible...
Thanks!
Helge
...
> diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
> index 25a2f5255f52..1acb77780f10 100644
> --- a/include/uapi/asm-generic/socket.h
> +++ b/include/uapi/asm-generic/socket.h
> @@ -135,6 +135,7 @@
> #define SO_PASSPIDFD 76
> #define SO_PEERPIDFD 77
>
> +#define SO_DEVMEM_DONTNEED 97
> #define SO_DEVMEM_LINEAR 98
> #define SCM_DEVMEM_LINEAR SO_DEVMEM_LINEAR
> #define SO_DEVMEM_DMABUF 99
On 12/18/23 02:40, Mina Almasry wrote:
> Implement netdev devmem allocator. The allocator takes a given struct
> netdev_dmabuf_binding as input and allocates net_iov from that
> binding.
>
> The allocation simply delegates to the binding's genpool for the
> allocation logic and wraps the returned memory region in a net_iov
> struct.
>
> Signed-off-by: Willem de Bruijn <[email protected]>
> Signed-off-by: Kaiyuan Zhang <[email protected]>
> Signed-off-by: Mina Almasry <[email protected]>
>
> ---
>
> v1:
> - Rename devmem -> dmabuf (David).
>
> ---
> include/net/devmem.h | 12 ++++++++++++
> include/net/netmem.h | 26 ++++++++++++++++++++++++++
> net/core/dev.c | 38 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 76 insertions(+)
>
..
> diff --git a/include/net/netmem.h b/include/net/netmem.h
> index 45eb42d9990b..7fce2efc8707 100644
> --- a/include/net/netmem.h
> +++ b/include/net/netmem.h
> @@ -14,8 +14,34 @@
>
> struct net_iov {
> struct dmabuf_genpool_chunk_owner *owner;
> + unsigned long dma_addr;
> };
>
> +static inline struct dmabuf_genpool_chunk_owner *
> +net_iov_owner(const struct net_iov *niov)
> +{
> + return niov->owner;
> +}
> +
> +static inline unsigned int net_iov_idx(const struct net_iov *niov)
> +{
> + return niov - net_iov_owner(niov)->niovs;
> +}
> +
> +static inline dma_addr_t net_iov_dma_addr(const struct net_iov *niov)
> +{
> + struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov);
> +
> + return owner->base_dma_addr +
> + ((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT);
Looks like it should have been niov->dma_addr
> +}
> +
> +static inline struct netdev_dmabuf_binding *
> +net_iov_binding(const struct net_iov *niov)
> +{
> + return net_iov_owner(niov)->binding;
> +}
> +
> /* netmem */
>
> struct netmem {
..
--
Pavel Begunkov
On 12/18/23 02:40, Mina Almasry wrote:
> Implement a memory provider that allocates dmabuf devmem in the form of
> net_iov.
>
> The provider receives a reference to the struct netdev_dmabuf_binding
> via the pool->mp_priv pointer. The driver needs to set this pointer for
> the provider in the net_iov.
>
> The provider obtains a reference on the netdev_dmabuf_binding which
> guarantees the binding and the underlying mapping remains alive until
> the provider is destroyed.
>
> Usage of PP_FLAG_DMA_MAP is required for this memory provide such that
> the page_pool can provide the driver with the dma-addrs of the devmem.
>
> Support for PP_FLAG_DMA_SYNC_DEV is omitted for simplicity & p.order !=
> 0.
>
> Signed-off-by: Willem de Bruijn <[email protected]>
> Signed-off-by: Kaiyuan Zhang <[email protected]>
> Signed-off-by: Mina Almasry <[email protected]>
>
> ---
..
> +
> +static bool mp_dmabuf_devmem_release_page(struct page_pool *pool,
> + struct netmem *netmem)
> +{
> + WARN_ON_ONCE(!netmem_is_net_iov(netmem));
> +
> + page_pool_clear_pp_info(netmem);
> +
> + netdev_free_dmabuf(netmem_to_net_iov(netmem));
> +
> + /* We don't want the page pool put_page()ing our net_iovs. */
> + return false;
> +}
> +
> +const struct memory_provider_ops dmabuf_devmem_ops = {
> + .init = mp_dmabuf_devmem_init,
> + .destroy = mp_dmabuf_devmem_destroy,
> + .alloc_pages = mp_dmabuf_devmem_alloc_pages,
> + .release_page = mp_dmabuf_devmem_release_page,
> +};
> +EXPORT_SYMBOL(dmabuf_devmem_ops);
It might make sense to move all these functions together with
new code from core/dev.c into a new file
--
Pavel Begunkov
On Tue, Feb 13, 2024 at 5:24 AM Pavel Begunkov <[email protected]> wrote:
>
> On 12/18/23 02:40, Mina Almasry wrote:
> > Implement netdev devmem allocator. The allocator takes a given struct
> > netdev_dmabuf_binding as input and allocates net_iov from that
> > binding.
> >
> > The allocation simply delegates to the binding's genpool for the
> > allocation logic and wraps the returned memory region in a net_iov
> > struct.
> >
> > Signed-off-by: Willem de Bruijn <[email protected]>
> > Signed-off-by: Kaiyuan Zhang <[email protected]>
> > Signed-off-by: Mina Almasry <[email protected]>
> >
> > ---
> >
> > v1:
> > - Rename devmem -> dmabuf (David).
> >
> > ---
> > include/net/devmem.h | 12 ++++++++++++
> > include/net/netmem.h | 26 ++++++++++++++++++++++++++
> > net/core/dev.c | 38 ++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 76 insertions(+)
> >
> ...
> > diff --git a/include/net/netmem.h b/include/net/netmem.h
> > index 45eb42d9990b..7fce2efc8707 100644
> > --- a/include/net/netmem.h
> > +++ b/include/net/netmem.h
> > @@ -14,8 +14,34 @@
> >
> > struct net_iov {
> > struct dmabuf_genpool_chunk_owner *owner;
> > + unsigned long dma_addr;
> > };
> >
> > +static inline struct dmabuf_genpool_chunk_owner *
> > +net_iov_owner(const struct net_iov *niov)
> > +{
> > + return niov->owner;
> > +}
> > +
> > +static inline unsigned int net_iov_idx(const struct net_iov *niov)
> > +{
> > + return niov - net_iov_owner(niov)->niovs;
> > +}
> > +
> > +static inline dma_addr_t net_iov_dma_addr(const struct net_iov *niov)
> > +{
> > + struct dmabuf_genpool_chunk_owner *owner = net_iov_owner(niov);
> > +
> > + return owner->base_dma_addr +
> > + ((dma_addr_t)net_iov_idx(niov) << PAGE_SHIFT);
>
> Looks like it should have been niov->dma_addr
>
Yes, indeed. Thanks for catching.
> > +}
> > +
> > +static inline struct netdev_dmabuf_binding *
> > +net_iov_binding(const struct net_iov *niov)
> > +{
> > + return net_iov_owner(niov)->binding;
> > +}
> > +
> > /* netmem */
> >
> > struct netmem {
> ...
>
> --
> Pavel Begunkov
--
Thanks,
Mina
On Tue, Feb 13, 2024 at 5:28 AM Pavel Begunkov <[email protected]> wrote:
>
> On 12/18/23 02:40, Mina Almasry wrote:
> > Convert netmem to be a union of struct page and struct netmem. Overload
> > the LSB of struct netmem* to indicate that it's a net_iov, otherwise
> > it's a page.
> >
> > Currently these entries in struct page are rented by the page_pool and
> > used exclusively by the net stack:
> >
> > struct {
> > unsigned long pp_magic;
> > struct page_pool *pp;
> > unsigned long _pp_mapping_pad;
> > unsigned long dma_addr;
> > atomic_long_t pp_ref_count;
> > };
> >
> > Mirror these (and only these) entries into struct net_iov and implement
> > netmem helpers that can access these common fields regardless of
> > whether the underlying type is page or net_iov.
> > Implement checks for net_iov in netmem helpers which delegate to mm
> > APIs, to ensure net_iov are never passed to the mm stack.
> >
> > Signed-off-by: Mina Almasry <[email protected]>
> >
> > ---
> >
> > RFCv5:
> > - Use netmem instead of page* with LSB set.
> > - Use pp_ref_count for refcounting net_iov.
> > - Removed many of the custom checks for netmem.
> >
> > v1:
> > - Disable fragmentation support for iov properly.
> > - fix napi_pp_put_page() path (Yunsheng).
> > - Use pp_frag_count for devmem refcounting.
> >
> > ---
> > include/net/netmem.h | 145 ++++++++++++++++++++++++++++++--
> > include/net/page_pool/helpers.h | 25 +++---
> > net/core/page_pool.c | 26 +++---
> > net/core/skbuff.c | 9 +-
> > 4 files changed, 164 insertions(+), 41 deletions(-)
> >
> > diff --git a/include/net/netmem.h b/include/net/netmem.h
> > index 31f338f19da0..7557aecc0f78 100644
> > --- a/include/net/netmem.h
> > +++ b/include/net/netmem.h
> > @@ -12,11 +12,47 @@
> >
> > /* net_iov */
> >
> > +DECLARE_STATIC_KEY_FALSE(page_pool_mem_providers);
> > +
> > +/* We overload the LSB of the struct page pointer to indicate whether it's
> > + * a page or net_iov.
> > + */
> > +#define NET_IOV 0x01UL
> > +
> > struct net_iov {
> > + unsigned long __unused_padding;
> > + unsigned long pp_magic;
> > + struct page_pool *pp;
> > struct dmabuf_genpool_chunk_owner *owner;
> > unsigned long dma_addr;
> > + atomic_long_t pp_ref_count;
> > };
>
> I wonder if it would be better to extract a common sub-struct
> used in struct page, struct_group_tagged can help to avoid
> touching old code:
>
> struct page {
> unsigned long flags;
> union {
> ...
> struct_group_tagged(<struct_name>, ...,
> /**
> * @pp_magic: magic value to avoid recycling non
> * page_pool allocated pages.
> */
> unsigned long pp_magic;
> struct page_pool *pp;
> unsigned long _pp_mapping_pad;
> unsigned long dma_addr;
> atomic_long_t pp_ref_count;
> );
> };
> }
>
> struct net_iov {
> unsigned long pad;
> struct <struct_name> p;
> };
>
>
> A bit of a churn with the padding and nesting net_iov but looks
> sturdier. No duplication, and you can just check positions of the
> structure instead of per-field NET_IOV_ASSERT_OFFSET, which you
> have to not forget to update e.g. when adding a new field. Also,
Yes, this is nicer. If possible I'll punt it to a minor cleanup as a
follow up change. Logistically I think if this series need-not touch
code outside of net/, that's better.
> with the change __netmem_clear_lsb can return a pointer to that
> structure, casting struct net_iov when it's a page is a bit iffy.
>
> And the next question would be whether it'd be a good idea to encode
> iov vs page not by setting a bit but via one of the fields in the
> structure, maybe pp_magic.
>
I will push back against this, for 2 reasons:
1. I think pp_magic's first 2 bits (and maybe more) are used by mm
code and thus I think extending usage of pp_magic in this series is a
bit iffy and I would like to avoid it. I just don't want to touch the
semantics of struct page if I don't have to.
2. I think this will be a measurable perf regression. Currently we can
tell if a pointer is a page or net_iov without dereferencing the
pointer and dirtying the cache-line. This will cause us to possibly
dereference the pointer in areas where we don't need to. I think I had
an earlier version of this code that required a dereference to tell if
a page was devmem and Eric pointed to me it was a perf regression.
I also don't see any upside of using pp_magic, other than making the
code slightly more readable, maybe.
> With that said I'm a bit concerned about the net_iov size. If each
> represents 4096 bytes and you're registering 10MB, then you need
> 30 pages worth of memory just for the iov array. Makes kvmalloc
> a must even for relatively small sizes.
>
This I think is an age-old challenge with pages. 1.6% of the machine's
memory is 'wasted' on every machine because a struct page needs to be
allocated for each PAGE_SIZE region. We're running into the same issue
here where if we want to refer to PAGE_SIZE regions of memory we need
to allocate some reference to it. Note that net_iov can be relatively
easily extended to support N order pages. Also note that in the devmem
TCP use case it's not really an issue; the minor increase in mem
utilization is more than offset by the saving in memory bw as compared
to using host memory as a bounce buffer. All in all I vote this is
something that can be tuned or improved in the future if someone finds
the extra memory usage a hurdle to using devmem TCP or this net_iov
infra.
> And the final bit, I don't believe the overlay is necessary in
> this series. Optimisations are great, but this one is a bit more on
> the controversial side. Unless I missed something and it does make
> things easier, it might make sense to do it separately later.
>
I completely agree, the overlay is not necessary. I implemented the
overlay in response to Yunsheng's strong requests for more 'unified'
processing between page and devmem. This is the most unification I can
do IMO without violating the requirements from Jason. I'm prepared to
remove the overlay if it turns out controversial, but so far I haven't
seen any complaints. Jason, please do take a look if you have not
already.
>
> > +/* These fields in struct page are used by the page_pool and net stack:
> > + *
> > + * struct {
> > + * unsigned long pp_magic;
> > + * struct page_pool *pp;
> > + * unsigned long _pp_mapping_pad;
> > + * unsigned long dma_addr;
> > + * atomic_long_t pp_ref_count;
> > + * };
> > + *
> > + * We mirror the page_pool fields here so the page_pool can access these fields
> > + * without worrying whether the underlying fields belong to a page or net_iov.
> > + *
> > + * The non-net stack fields of struct page are private to the mm stack and must
> > + * never be mirrored to net_iov.
> > + */
> > +#define NET_IOV_ASSERT_OFFSET(pg, iov) \
> > + static_assert(offsetof(struct page, pg) == \
> > + offsetof(struct net_iov, iov))
> > +NET_IOV_ASSERT_OFFSET(pp_magic, pp_magic);
> > +NET_IOV_ASSERT_OFFSET(pp, pp);
> > +NET_IOV_ASSERT_OFFSET(dma_addr, dma_addr);
> > +NET_IOV_ASSERT_OFFSET(pp_ref_count, pp_ref_count);
> > +#undef NET_IOV_ASSERT_OFFSET
> > +
> > static inline struct dmabuf_genpool_chunk_owner *
> > net_iov_owner(const struct net_iov *niov)
> > {
> > @@ -47,19 +83,25 @@ net_iov_binding(const struct net_iov *niov)
> > struct netmem {
> > union {
> > struct page page;
> > -
> > - /* Stub to prevent compiler implicitly converting from page*
> > - * to netmem_t* and vice versa.
> > - *
> > - * Other memory type(s) net stack would like to support
> > - * can be added to this union.
> > - */
> > - void *addr;
> > + struct net_iov niov;
> > };
> > };
> >
> ...
>
> --
> Pavel Begunkov
--
Thanks,
Mina