This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory
owned by a device that can be mapped into CPU page tables like
MEMORY_DEVICE_GENERIC and can also be migrated like
MEMORY_DEVICE_PRIVATE.
Christoph, the suggestion to incorporate Ralph Campbell’s refcount
cleanup patch into our hardware page migration patchset originally came
from you, but it proved impractical to do things in that order because
the refcount cleanup introduced a bug with wide ranging structural
implications. Instead, we amended Ralph’s patch so that it could be
applied after merging the migration work. As we saw from the recent
discussion, merging the refcount work is going to take some time and
cooperation between multiple development groups, while the migration
work is ready now and is needed now. So we propose to merge this
patchset first and continue to work with Ralph and others to merge the
refcount cleanup separately, when it is ready.
This patch series is mostly self-contained except for a few places where
it needs to update other subsystems to handle the new memory type.
System stability and performance are not affected according to our
ongoing testing, including xfstests.
How it works: The system BIOS advertises the GPU device memory
(aka VRAM) as SPM (special purpose memory) in the UEFI system address
map.
The amdgpu driver registers the memory with devmap as
MEMORY_DEVICE_COHERENT using devm_memremap_pages. The initial user for
this hardware page migration capability is the Frontier supercomputer
project. This functionality is not AMD-specific. We expect other GPU
vendors to find this functionality useful, and possibly other hardware
types in the future.
Our test nodes in the lab are similar to the Frontier configuration,
with .5 TB of system memory plus 256 GB of device memory split across
4 GPUs, all in a single coherent address space. Page migration is
expected to improve application efficiency significantly. We will
report empirical results as they become available.
We extended hmm_test to cover migration of MEMORY_DEVICE_COHERENT. This
patch set builds on HMM and our SVM memory manager already merged in
5.15.
v2:
- test_hmm is now able to create private and coherent device mirror
instances in the same driver probe. This adds more usability to the hmm
test by not having to remove the kernel module for each device type
test (private/coherent type). This is done by passing the module
parameters spm_addr_dev0 & spm_addr_dev1. In this case, it will create
four instances of device_mirror. The first two correspond to private
device type, the last two to coherent type. Then, they can be easily
accessed from user space through /dev/hmm_mirror<num_device>. Usually
num_device 0 and 1 are for private, and 2 and 3 for coherent types.
- Coherent device type pages at gup are now migrated back to system
memory if they have been long term pinned (FOLL_LONGTERM). The reason
is these pages could eventually interfere with their own device memory
manager. A new hmm_gup_test has been added to the hmm-test to test this
functionality. It makes use of the gup_test module to long term pin
user pages that have been migrate to device memory first.
- Other patch corrections made by Felix, Alistair and Christoph.
v3:
- Based on last v2 feedback we got from Alistair, we've decided to
remove migration logic for FOLL_LONGTERM coherent device type pages at
gup for now. Ideally, this should be done through the kernel mm,
instead of calling the device driver to do it. Currently, there's no
support for migrating device pages based on pfn, mainly because
migrate_pages() relies on pages being LRU pages. Alistair mentioned, he
has started to work on adding this migrate device pages logic. For now,
we fail on get_user_pages call with FOLL_LONGTERM for DEVICE_COHERENT
pages.
- Also, hmm_gup_test has been removed from hmm-test. We plan to include
it again after this migration work is ready.
- Addressed Liam Howlett's feedback changes.
v4:
- Addressed Alistair Popple's last v3 feedback.
- Use the same system entry path for coherent device pages at
migrate_vma_insert_page.
- Add coherent device type support for try_to_migrate /
try_to_migrate_one.
- Include number of coherent device pages successfully migrated back to
system at test_hmm. Made the proper changes to hmm-test to read/check
this number.
Alex Sierra (10):
mm: add zone device coherent type memory support
mm: add device coherent vma selection for memory migration
mm/gup: fail get_user_pages for LONGTERM dev coherent type
drm/amdkfd: add SPM support for SVM
drm/amdkfd: coherent type as sys mem on migration to ram
lib: test_hmm add ioctl to get zone device type
lib: test_hmm add module param for zone device type
lib: add support for device coherent type in test_hmm
tools: update hmm-test to support device coherent type
tools: update test_hmm script to support SP config
drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 34 ++-
include/linux/memremap.h | 8 +
include/linux/migrate.h | 1 +
include/linux/mm.h | 16 +
lib/test_hmm.c | 356 +++++++++++++++++------
lib/test_hmm_uapi.h | 22 +-
mm/gup.c | 7 +
mm/memcontrol.c | 6 +-
mm/memory-failure.c | 8 +-
mm/memremap.c | 14 +-
mm/migrate.c | 56 ++--
mm/rmap.c | 20 +-
tools/testing/selftests/vm/hmm-tests.c | 123 ++++++--
tools/testing/selftests/vm/test_hmm.sh | 24 +-
14 files changed, 529 insertions(+), 166 deletions(-)
--
2.32.0
This case is used to migrate pages from device memory, back to system
memory. Device coherent type memory is cache coherent from device and CPU
point of view.
Signed-off-by: Alex Sierra <[email protected]>
---
v2:
condition added when migrations from device coherent pages.
---
include/linux/migrate.h | 1 +
mm/migrate.c | 9 +++++++--
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index c8077e936691..e74bb0978f6f 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -138,6 +138,7 @@ static inline unsigned long migrate_pfn(unsigned long pfn)
enum migrate_vma_direction {
MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
+ MIGRATE_VMA_SELECT_DEVICE_COHERENT = 1 << 2,
};
struct migrate_vma {
diff --git a/mm/migrate.c b/mm/migrate.c
index 277562cd4cf5..2b3375e165b1 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2340,8 +2340,6 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
if (is_writable_device_private_entry(entry))
mpfn |= MIGRATE_PFN_WRITE;
} else {
- if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
- goto next;
pfn = pte_pfn(pte);
if (is_zero_pfn(pfn)) {
mpfn = MIGRATE_PFN_MIGRATE;
@@ -2349,6 +2347,13 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
goto next;
}
page = vm_normal_page(migrate->vma, addr, pte);
+ if (page && !is_zone_device_page(page) &&
+ !(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
+ goto next;
+ if (page && is_device_coherent_page(page) &&
+ (!(migrate->flags & MIGRATE_VMA_SELECT_DEVICE_COHERENT) ||
+ page->pgmap->owner != migrate->pgmap_owner))
+ goto next;
mpfn = migrate_pfn(pfn) | MIGRATE_PFN_MIGRATE;
mpfn |= pte_write(pte) ? MIGRATE_PFN_WRITE : 0;
}
--
2.32.0
Coherent device type memory on VRAM to RAM migration, has similar access
as System RAM from the CPU. This flag sets the source from the sender.
Which in Coherent type case, should be set as
MIGRATE_VMA_SELECT_DEVICE_COHERENT.
Signed-off-by: Alex Sierra <[email protected]>
Reviewed-by: Felix Kuehling <[email protected]>
---
drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index 9e36fe8aea0f..3e405f078ade 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -661,9 +661,12 @@ svm_migrate_vma_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
migrate.vma = vma;
migrate.start = start;
migrate.end = end;
- migrate.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
+ if (adev->gmc.xgmi.connected_to_cpu)
+ migrate.flags = MIGRATE_VMA_SELECT_DEVICE_COHERENT;
+ else
+ migrate.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
size = 2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t);
size *= npages;
buf = kvmalloc(size, GFP_KERNEL | __GFP_ZERO);
--
2.32.0
Avoid long term pinning for Coherent device type pages. This could
interfere with their own device memory manager. For now, we are just
returning error for PIN_LONGTERM Coherent device type pages. Eventually,
these type of pages will get migrated to system memory, once the device
migration pages support is added.
Signed-off-by: Alex Sierra <[email protected]>
---
mm/gup.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/mm/gup.c b/mm/gup.c
index 886d6148d3d0..5291d7221826 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1720,6 +1720,12 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages,
* If we get a movable page, since we are going to be pinning
* these entries, try to move them out if possible.
*/
+ if (is_dev_private_or_coherent_page(head)) {
+ WARN_ON_ONCE(is_device_private_page(head));
+ ret = -EFAULT;
+ goto unpin_pages;
+ }
+
if (!is_pinnable_page(head)) {
if (PageHuge(head)) {
if (!isolate_huge_page(head, &movable_page_list))
@@ -1750,6 +1756,7 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages,
if (list_empty(&movable_page_list) && !isolation_error_count)
return nr_pages;
+unpin_pages:
if (gup_flags & FOLL_PIN) {
unpin_user_pages(pages, nr_pages);
} else {
--
2.32.0
When CPU is connected throug XGMI, it has coherent
access to VRAM resource. In this case that resource
is taken from a table in the device gmc aperture base.
This resource is used along with the device type, which could
be DEVICE_PRIVATE or DEVICE_COHERENT to create the device
page map region.
Signed-off-by: Alex Sierra <[email protected]>
Reviewed-by: Felix Kuehling <[email protected]>
---
v7:
Remove lookup_resource call, so export symbol for this function
is not longer required. Patch dropped "kernel: resource:
lookup_resource as exported symbol"
---
drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 29 +++++++++++++++---------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index aeade32ec298..9e36fe8aea0f 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -935,7 +935,7 @@ int svm_migrate_init(struct amdgpu_device *adev)
{
struct kfd_dev *kfddev = adev->kfd.dev;
struct dev_pagemap *pgmap;
- struct resource *res;
+ struct resource *res = NULL;
unsigned long size;
void *r;
@@ -950,28 +950,34 @@ int svm_migrate_init(struct amdgpu_device *adev)
* should remove reserved size
*/
size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
- res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
- if (IS_ERR(res))
- return -ENOMEM;
+ if (adev->gmc.xgmi.connected_to_cpu) {
+ pgmap->range.start = adev->gmc.aper_base;
+ pgmap->range.end = adev->gmc.aper_base + adev->gmc.aper_size - 1;
+ pgmap->type = MEMORY_DEVICE_COHERENT;
+ } else {
+ res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
+ if (IS_ERR(res))
+ return -ENOMEM;
+ pgmap->range.start = res->start;
+ pgmap->range.end = res->end;
+ pgmap->type = MEMORY_DEVICE_PRIVATE;
+ }
- pgmap->type = MEMORY_DEVICE_PRIVATE;
pgmap->nr_range = 1;
- pgmap->range.start = res->start;
- pgmap->range.end = res->end;
pgmap->ops = &svm_migrate_pgmap_ops;
pgmap->owner = SVM_ADEV_PGMAP_OWNER(adev);
- pgmap->flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
-
+ pgmap->flags = 0;
/* Device manager releases device-specific resources, memory region and
* pgmap when driver disconnects from device.
*/
r = devm_memremap_pages(adev->dev, pgmap);
if (IS_ERR(r)) {
pr_err("failed to register HMM device memory\n");
-
/* Disable SVM support capability */
pgmap->type = 0;
- devm_release_mem_region(adev->dev, res->start, resource_size(res));
+ if (pgmap->type == MEMORY_DEVICE_PRIVATE)
+ devm_release_mem_region(adev->dev, res->start,
+ res->end - res->start + 1);
return PTR_ERR(r);
}
@@ -984,3 +990,4 @@ int svm_migrate_init(struct amdgpu_device *adev)
return 0;
}
+
--
2.32.0
new ioctl cmd added to query zone device type. This will be
used once the test_hmm adds zone device coherent type.
Signed-off-by: Alex Sierra <[email protected]>
---
lib/test_hmm.c | 23 +++++++++++++++++++++--
lib/test_hmm_uapi.h | 8 ++++++++
2 files changed, 29 insertions(+), 2 deletions(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index c259842f6d44..fb1fa7c6fa98 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -84,6 +84,7 @@ struct dmirror_chunk {
struct dmirror_device {
struct cdev cdevice;
struct hmm_devmem *devmem;
+ unsigned int zone_device_type;
unsigned int devmem_capacity;
unsigned int devmem_count;
@@ -1025,6 +1026,15 @@ static int dmirror_snapshot(struct dmirror *dmirror,
return ret;
}
+static int dmirror_get_device_type(struct dmirror *dmirror,
+ struct hmm_dmirror_cmd *cmd)
+{
+ mutex_lock(&dmirror->mutex);
+ cmd->zone_device_type = dmirror->mdevice->zone_device_type;
+ mutex_unlock(&dmirror->mutex);
+
+ return 0;
+}
static long dmirror_fops_unlocked_ioctl(struct file *filp,
unsigned int command,
unsigned long arg)
@@ -1075,6 +1085,9 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp,
ret = dmirror_snapshot(dmirror, &cmd);
break;
+ case HMM_DMIRROR_GET_MEM_DEV_TYPE:
+ ret = dmirror_get_device_type(dmirror, &cmd);
+ break;
default:
return -EINVAL;
}
@@ -1235,14 +1248,20 @@ static void dmirror_device_remove(struct dmirror_device *mdevice)
static int __init hmm_dmirror_init(void)
{
int ret;
- int id;
+ int id = 0;
+ int ndevices = 0;
ret = alloc_chrdev_region(&dmirror_dev, 0, DMIRROR_NDEVICES,
"HMM_DMIRROR");
if (ret)
goto err_unreg;
- for (id = 0; id < DMIRROR_NDEVICES; id++) {
+ memset(dmirror_devices, 0, DMIRROR_NDEVICES * sizeof(dmirror_devices[0]));
+ dmirror_devices[ndevices++].zone_device_type =
+ HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
+ dmirror_devices[ndevices++].zone_device_type =
+ HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
+ for (id = 0; id < ndevices; id++) {
ret = dmirror_device_init(dmirror_devices + id, id);
if (ret)
goto err_chrdev;
diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
index f14dea5dcd06..17f842f1aa02 100644
--- a/lib/test_hmm_uapi.h
+++ b/lib/test_hmm_uapi.h
@@ -19,6 +19,7 @@
* @npages: (in) number of pages to read/write
* @cpages: (out) number of pages copied
* @faults: (out) number of device page faults seen
+ * @zone_device_type: (out) zone device memory type
*/
struct hmm_dmirror_cmd {
__u64 addr;
@@ -26,6 +27,7 @@ struct hmm_dmirror_cmd {
__u64 npages;
__u64 cpages;
__u64 faults;
+ __u64 zone_device_type;
};
/* Expose the address space of the calling process through hmm device file */
@@ -35,6 +37,7 @@ struct hmm_dmirror_cmd {
#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x03, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x04, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)
+#define HMM_DMIRROR_GET_MEM_DEV_TYPE _IOWR('H', 0x06, struct hmm_dmirror_cmd)
/*
* Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
@@ -62,4 +65,9 @@ enum {
HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30,
};
+enum {
+ /* 0 is reserved to catch uninitialized type fields */
+ HMM_DMIRROR_MEMORY_DEVICE_PRIVATE = 1,
+};
+
#endif /* _LIB_TEST_HMM_UAPI_H */
--
2.32.0
In order to configure device coherent in test_hmm, two module parameters
should be passed, which correspond to the SP start address of each
device (2) spm_addr_dev0 & spm_addr_dev1. If no parameters are passed,
private device type is configured.
Signed-off-by: Alex Sierra <[email protected]>
---
lib/test_hmm.c | 73 ++++++++++++++++++++++++++++++++-------------
lib/test_hmm_uapi.h | 1 +
2 files changed, 53 insertions(+), 21 deletions(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index fb1fa7c6fa98..6f068f7c4ee3 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -34,6 +34,16 @@
#define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U)
#define DEVMEM_CHUNKS_RESERVE 16
+static unsigned long spm_addr_dev0;
+module_param(spm_addr_dev0, long, 0644);
+MODULE_PARM_DESC(spm_addr_dev0,
+ "Specify start address for SPM (special purpose memory) used for device 0. By setting this Coherent device type will be used. Make sure spm_addr_dev1 is set too. Minimum SPM size should be DEVMEM_CHUNK_SIZE.");
+
+static unsigned long spm_addr_dev1;
+module_param(spm_addr_dev1, long, 0644);
+MODULE_PARM_DESC(spm_addr_dev1,
+ "Specify start address for SPM (special purpose memory) used for device 1. By setting this Coherent device type will be used. Make sure spm_addr_dev0 is set too. Minimum SPM size should be DEVMEM_CHUNK_SIZE.");
+
static const struct dev_pagemap_ops dmirror_devmem_ops;
static const struct mmu_interval_notifier_ops dmirror_min_ops;
static dev_t dmirror_dev;
@@ -452,28 +462,44 @@ static int dmirror_write(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd)
return ret;
}
-static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
+static int dmirror_allocate_chunk(struct dmirror_device *mdevice,
struct page **ppage)
{
struct dmirror_chunk *devmem;
- struct resource *res;
+ struct resource *res = NULL;
unsigned long pfn;
unsigned long pfn_first;
unsigned long pfn_last;
void *ptr;
+ int ret = -ENOMEM;
devmem = kzalloc(sizeof(*devmem), GFP_KERNEL);
if (!devmem)
- return false;
+ return ret;
- res = request_free_mem_region(&iomem_resource, DEVMEM_CHUNK_SIZE,
- "hmm_dmirror");
- if (IS_ERR(res))
+ switch (mdevice->zone_device_type) {
+ case HMM_DMIRROR_MEMORY_DEVICE_PRIVATE:
+ res = request_free_mem_region(&iomem_resource, DEVMEM_CHUNK_SIZE,
+ "hmm_dmirror");
+ if (IS_ERR_OR_NULL(res))
+ goto err_devmem;
+ devmem->pagemap.range.start = res->start;
+ devmem->pagemap.range.end = res->end;
+ devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
+ break;
+ case HMM_DMIRROR_MEMORY_DEVICE_COHERENT:
+ devmem->pagemap.range.start = (MINOR(mdevice->cdevice.dev) - 2) ?
+ spm_addr_dev0 :
+ spm_addr_dev1;
+ devmem->pagemap.range.end = devmem->pagemap.range.start +
+ DEVMEM_CHUNK_SIZE - 1;
+ devmem->pagemap.type = MEMORY_DEVICE_COHERENT;
+ break;
+ default:
+ ret = -EINVAL;
goto err_devmem;
+ }
- devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
- devmem->pagemap.range.start = res->start;
- devmem->pagemap.range.end = res->end;
devmem->pagemap.nr_range = 1;
devmem->pagemap.ops = &dmirror_devmem_ops;
devmem->pagemap.owner = mdevice;
@@ -494,10 +520,14 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
mdevice->devmem_capacity = new_capacity;
mdevice->devmem_chunks = new_chunks;
}
-
ptr = memremap_pages(&devmem->pagemap, numa_node_id());
- if (IS_ERR(ptr))
+ if (IS_ERR_OR_NULL(ptr)) {
+ if (ptr)
+ ret = PTR_ERR(ptr);
+ else
+ ret = -EFAULT;
goto err_release;
+ }
devmem->mdevice = mdevice;
pfn_first = devmem->pagemap.range.start >> PAGE_SHIFT;
@@ -526,15 +556,17 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
}
spin_unlock(&mdevice->lock);
- return true;
+ return 0;
err_release:
mutex_unlock(&mdevice->devmem_lock);
- release_mem_region(devmem->pagemap.range.start, range_len(&devmem->pagemap.range));
+ if (res && devmem->pagemap.type == MEMORY_DEVICE_PRIVATE)
+ release_mem_region(devmem->pagemap.range.start,
+ range_len(&devmem->pagemap.range));
err_devmem:
kfree(devmem);
- return false;
+ return ret;
}
static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
@@ -559,7 +591,7 @@ static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
spin_unlock(&mdevice->lock);
} else {
spin_unlock(&mdevice->lock);
- if (!dmirror_allocate_chunk(mdevice, &dpage))
+ if (dmirror_allocate_chunk(mdevice, &dpage))
goto error;
}
@@ -1219,10 +1251,8 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id)
if (ret)
return ret;
- /* Build a list of free ZONE_DEVICE private struct pages */
- dmirror_allocate_chunk(mdevice, NULL);
-
- return 0;
+ /* Build a list of free ZONE_DEVICE struct pages */
+ return dmirror_allocate_chunk(mdevice, NULL);
}
static void dmirror_device_remove(struct dmirror_device *mdevice)
@@ -1235,8 +1265,9 @@ static void dmirror_device_remove(struct dmirror_device *mdevice)
mdevice->devmem_chunks[i];
memunmap_pages(&devmem->pagemap);
- release_mem_region(devmem->pagemap.range.start,
- range_len(&devmem->pagemap.range));
+ if (devmem->pagemap.type == MEMORY_DEVICE_PRIVATE)
+ release_mem_region(devmem->pagemap.range.start,
+ range_len(&devmem->pagemap.range));
kfree(devmem);
}
kfree(mdevice->devmem_chunks);
diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
index 17f842f1aa02..625f3690d086 100644
--- a/lib/test_hmm_uapi.h
+++ b/lib/test_hmm_uapi.h
@@ -68,6 +68,7 @@ enum {
enum {
/* 0 is reserved to catch uninitialized type fields */
HMM_DMIRROR_MEMORY_DEVICE_PRIVATE = 1,
+ HMM_DMIRROR_MEMORY_DEVICE_COHERENT,
};
#endif /* _LIB_TEST_HMM_UAPI_H */
--
2.32.0
Test cases such as migrate_fault and migrate_multiple, were modified to
explicit migrate from device to sys memory without the need of page
faults, when using device coherent type.
Snapshot test case updated to read memory device type first and based
on that, get the proper returned results migrate_ping_pong test case
added to test explicit migration from device to sys memory for both
private and coherent zone types.
Helpers to migrate from device to sys memory and vicerversa
were also added.
Signed-off-by: Alex Sierra <[email protected]>
---
v2:
Set FIXTURE_VARIANT to add multiple device types to the FIXTURE. This
will run all the tests for each device type (private and coherent) in
case both existed during hmm-test driver probed.
v4:
Check for the number of pages successfully migrated from coherent
device to system at migrate_multiple test.
---
tools/testing/selftests/vm/hmm-tests.c | 123 ++++++++++++++++++++-----
1 file changed, 102 insertions(+), 21 deletions(-)
diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index 864f126ffd78..99de5e38dbbc 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -44,6 +44,14 @@ struct hmm_buffer {
int fd;
uint64_t cpages;
uint64_t faults;
+ int zone_device_type;
+};
+
+enum {
+ HMM_PRIVATE_DEVICE_ONE,
+ HMM_PRIVATE_DEVICE_TWO,
+ HMM_COHERENCE_DEVICE_ONE,
+ HMM_COHERENCE_DEVICE_TWO,
};
#define TWOMEG (1 << 21)
@@ -60,6 +68,21 @@ FIXTURE(hmm)
unsigned int page_shift;
};
+FIXTURE_VARIANT(hmm)
+{
+ int device_number;
+};
+
+FIXTURE_VARIANT_ADD(hmm, hmm_device_private)
+{
+ .device_number = HMM_PRIVATE_DEVICE_ONE,
+};
+
+FIXTURE_VARIANT_ADD(hmm, hmm_device_coherent)
+{
+ .device_number = HMM_COHERENCE_DEVICE_ONE,
+};
+
FIXTURE(hmm2)
{
int fd0;
@@ -68,6 +91,24 @@ FIXTURE(hmm2)
unsigned int page_shift;
};
+FIXTURE_VARIANT(hmm2)
+{
+ int device_number0;
+ int device_number1;
+};
+
+FIXTURE_VARIANT_ADD(hmm2, hmm2_device_private)
+{
+ .device_number0 = HMM_PRIVATE_DEVICE_ONE,
+ .device_number1 = HMM_PRIVATE_DEVICE_TWO,
+};
+
+FIXTURE_VARIANT_ADD(hmm2, hmm2_device_coherent)
+{
+ .device_number0 = HMM_COHERENCE_DEVICE_ONE,
+ .device_number1 = HMM_COHERENCE_DEVICE_TWO,
+};
+
static int hmm_open(int unit)
{
char pathname[HMM_PATH_MAX];
@@ -81,12 +122,19 @@ static int hmm_open(int unit)
return fd;
}
+static bool hmm_is_coherent_type(int dev_num)
+{
+ return (dev_num >= HMM_COHERENCE_DEVICE_ONE);
+}
+
FIXTURE_SETUP(hmm)
{
self->page_size = sysconf(_SC_PAGE_SIZE);
self->page_shift = ffs(self->page_size) - 1;
- self->fd = hmm_open(0);
+ self->fd = hmm_open(variant->device_number);
+ if (self->fd < 0 && hmm_is_coherent_type(variant->device_number))
+ SKIP(exit(0), "DEVICE_COHERENT not available");
ASSERT_GE(self->fd, 0);
}
@@ -95,9 +143,11 @@ FIXTURE_SETUP(hmm2)
self->page_size = sysconf(_SC_PAGE_SIZE);
self->page_shift = ffs(self->page_size) - 1;
- self->fd0 = hmm_open(0);
+ self->fd0 = hmm_open(variant->device_number0);
+ if (self->fd0 < 0 && hmm_is_coherent_type(variant->device_number0))
+ SKIP(exit(0), "DEVICE_COHERENT not available");
ASSERT_GE(self->fd0, 0);
- self->fd1 = hmm_open(1);
+ self->fd1 = hmm_open(variant->device_number1);
ASSERT_GE(self->fd1, 0);
}
@@ -144,6 +194,7 @@ static int hmm_dmirror_cmd(int fd,
}
buffer->cpages = cmd.cpages;
buffer->faults = cmd.faults;
+ buffer->zone_device_type = cmd.zone_device_type;
return 0;
}
@@ -211,6 +262,20 @@ static void hmm_nanosleep(unsigned int n)
nanosleep(&t, NULL);
}
+static int hmm_migrate_sys_to_dev(int fd,
+ struct hmm_buffer *buffer,
+ unsigned long npages)
+{
+ return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_TO_DEV, buffer, npages);
+}
+
+static int hmm_migrate_dev_to_sys(int fd,
+ struct hmm_buffer *buffer,
+ unsigned long npages)
+{
+ return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_TO_SYS, buffer, npages);
+}
+
/*
* Simple NULL test of device open/close.
*/
@@ -875,7 +940,7 @@ TEST_F(hmm, migrate)
ptr[i] = i;
/* Migrate memory to device. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, npages);
@@ -923,7 +988,7 @@ TEST_F(hmm, migrate_fault)
ptr[i] = i;
/* Migrate memory to device. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, npages);
@@ -936,7 +1001,7 @@ TEST_F(hmm, migrate_fault)
ASSERT_EQ(ptr[i], i);
/* Migrate memory to the device again. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, npages);
@@ -976,7 +1041,7 @@ TEST_F(hmm, migrate_shared)
ASSERT_NE(buffer->ptr, MAP_FAILED);
/* Migrate memory to device. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, -ENOENT);
hmm_buffer_free(buffer);
@@ -1015,7 +1080,7 @@ TEST_F(hmm2, migrate_mixed)
p = buffer->ptr;
/* Migrating a protected area should be an error. */
- ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, npages);
+ ret = hmm_migrate_sys_to_dev(self->fd1, buffer, npages);
ASSERT_EQ(ret, -EINVAL);
/* Punch a hole after the first page address. */
@@ -1023,7 +1088,7 @@ TEST_F(hmm2, migrate_mixed)
ASSERT_EQ(ret, 0);
/* We expect an error if the vma doesn't cover the range. */
- ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 3);
+ ret = hmm_migrate_sys_to_dev(self->fd1, buffer, 3);
ASSERT_EQ(ret, -EINVAL);
/* Page 2 will be a read-only zero page. */
@@ -1055,13 +1120,13 @@ TEST_F(hmm2, migrate_mixed)
/* Now try to migrate pages 2-5 to device 1. */
buffer->ptr = p + 2 * self->page_size;
- ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 4);
+ ret = hmm_migrate_sys_to_dev(self->fd1, buffer, 4);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, 4);
/* Page 5 won't be migrated to device 0 because it's on device 1. */
buffer->ptr = p + 5 * self->page_size;
- ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_MIGRATE, buffer, 1);
+ ret = hmm_migrate_sys_to_dev(self->fd0, buffer, 1);
ASSERT_EQ(ret, -ENOENT);
buffer->ptr = p;
@@ -1070,8 +1135,12 @@ TEST_F(hmm2, migrate_mixed)
}
/*
- * Migrate anonymous memory to device private memory and fault it back to system
- * memory multiple times.
+ * Migrate anonymous memory to device memory and back to system memory
+ * multiple times. In case of private zone configuration, this is done
+ * through fault pages accessed by CPU. In case of coherent zone configuration,
+ * the pages from the device should be explicitly migrated back to system memory.
+ * The reason is Coherent device zone has coherent access by CPU, therefore
+ * it will not generate any page fault.
*/
TEST_F(hmm, migrate_multiple)
{
@@ -1107,8 +1176,7 @@ TEST_F(hmm, migrate_multiple)
ptr[i] = i;
/* Migrate memory to device. */
- ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, buffer,
- npages);
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, npages);
@@ -1116,7 +1184,13 @@ TEST_F(hmm, migrate_multiple)
for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
ASSERT_EQ(ptr[i], i);
- /* Fault pages back to system memory and check them. */
+ /* Migrate back to system memory and check them. */
+ if (hmm_is_coherent_type(variant->device_number)) {
+ ret = hmm_migrate_dev_to_sys(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+ }
+
for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
ASSERT_EQ(ptr[i], i);
@@ -1312,13 +1386,13 @@ TEST_F(hmm2, snapshot)
/* Page 5 will be migrated to device 0. */
buffer->ptr = p + 5 * self->page_size;
- ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_MIGRATE, buffer, 1);
+ ret = hmm_migrate_sys_to_dev(self->fd0, buffer, 1);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, 1);
/* Page 6 will be migrated to device 1. */
buffer->ptr = p + 6 * self->page_size;
- ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 1);
+ ret = hmm_migrate_sys_to_dev(self->fd1, buffer, 1);
ASSERT_EQ(ret, 0);
ASSERT_EQ(buffer->cpages, 1);
@@ -1335,9 +1409,16 @@ TEST_F(hmm2, snapshot)
ASSERT_EQ(m[2], HMM_DMIRROR_PROT_ZERO | HMM_DMIRROR_PROT_READ);
ASSERT_EQ(m[3], HMM_DMIRROR_PROT_READ);
ASSERT_EQ(m[4], HMM_DMIRROR_PROT_WRITE);
- ASSERT_EQ(m[5], HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL |
- HMM_DMIRROR_PROT_WRITE);
- ASSERT_EQ(m[6], HMM_DMIRROR_PROT_NONE);
+ if (!hmm_is_coherent_type(variant->device_number0)) {
+ ASSERT_EQ(m[5], HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL |
+ HMM_DMIRROR_PROT_WRITE);
+ ASSERT_EQ(m[6], HMM_DMIRROR_PROT_NONE);
+ } else {
+ ASSERT_EQ(m[5], HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL |
+ HMM_DMIRROR_PROT_WRITE);
+ ASSERT_EQ(m[6], HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE |
+ HMM_DMIRROR_PROT_WRITE);
+ }
hmm_buffer_free(buffer);
}
--
2.32.0
Device Coherent type uses device memory that is coherently accesible by
the CPU. This could be shown as SP (special purpose) memory range
at the BIOS-e820 memory enumeration. If no SP memory is supported in
system, this could be faked by setting CONFIG_EFI_FAKE_MEMMAP.
Currently, test_hmm only supports two different SP ranges of at least
256MB size. This could be specified in the kernel parameter variable
efi_fake_mem. Ex. Two SP ranges of 1GB starting at 0x100000000 &
0x140000000 physical address. Ex.
efi_fake_mem=1G@0x100000000:0x40000,1G@0x140000000:0x40000
Private and coherent device mirror instances can be created in the same
probed. This is done by passing the module parameters spm_addr_dev0 &
spm_addr_dev1. In this case, it will create four instances of
device_mirror. The first two correspond to private device type, the
last two to coherent type. Then, they can be easily accessed from user
space through /dev/hmm_mirror<num_device>. Usually num_device 0 and 1
are for private, and 2 and 3 for coherent types. If no module
parameters are passed, two instances of private type device_mirror will
be created only.
Signed-off-by: Alex Sierra <[email protected]>
---
v4:
Return number of coherent device pages successfully migrated to system.
This is returned at cmd->cpages.
---
lib/test_hmm.c | 260 +++++++++++++++++++++++++++++++++-----------
lib/test_hmm_uapi.h | 15 ++-
2 files changed, 205 insertions(+), 70 deletions(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index 6f068f7c4ee3..850d5331e370 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -29,11 +29,22 @@
#include "test_hmm_uapi.h"
-#define DMIRROR_NDEVICES 2
+#define DMIRROR_NDEVICES 4
#define DMIRROR_RANGE_FAULT_TIMEOUT 1000
#define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U)
#define DEVMEM_CHUNKS_RESERVE 16
+/*
+ * For device_private pages, dpage is just a dummy struct page
+ * representing a piece of device memory. dmirror_devmem_alloc_page
+ * allocates a real system memory page as backing storage to fake a
+ * real device. zone_device_data points to that backing page. But
+ * for device_coherent memory, the struct page represents real
+ * physical CPU-accessible memory that we can use directly.
+ */
+#define BACKING_PAGE(page) (is_device_private_page((page)) ? \
+ (page)->zone_device_data : (page))
+
static unsigned long spm_addr_dev0;
module_param(spm_addr_dev0, long, 0644);
MODULE_PARM_DESC(spm_addr_dev0,
@@ -122,6 +133,21 @@ static int dmirror_bounce_init(struct dmirror_bounce *bounce,
return 0;
}
+static bool dmirror_is_private_zone(struct dmirror_device *mdevice)
+{
+ return (mdevice->zone_device_type ==
+ HMM_DMIRROR_MEMORY_DEVICE_PRIVATE) ? true : false;
+}
+
+static enum migrate_vma_direction
+ dmirror_select_device(struct dmirror *dmirror)
+{
+ return (dmirror->mdevice->zone_device_type ==
+ HMM_DMIRROR_MEMORY_DEVICE_PRIVATE) ?
+ MIGRATE_VMA_SELECT_DEVICE_PRIVATE :
+ MIGRATE_VMA_SELECT_DEVICE_COHERENT;
+}
+
static void dmirror_bounce_fini(struct dmirror_bounce *bounce)
{
vfree(bounce->ptr);
@@ -572,16 +598,19 @@ static int dmirror_allocate_chunk(struct dmirror_device *mdevice,
static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
{
struct page *dpage = NULL;
- struct page *rpage;
+ struct page *rpage = NULL;
/*
- * This is a fake device so we alloc real system memory to store
- * our device memory.
+ * For ZONE_DEVICE private type, this is a fake device so we alloc real
+ * system memory to store our device memory.
+ * For ZONE_DEVICE coherent type we use the actual dpage to store the data
+ * and ignore rpage.
*/
- rpage = alloc_page(GFP_HIGHUSER);
- if (!rpage)
- return NULL;
-
+ if (dmirror_is_private_zone(mdevice)) {
+ rpage = alloc_page(GFP_HIGHUSER);
+ if (!rpage)
+ return NULL;
+ }
spin_lock(&mdevice->lock);
if (mdevice->free_pages) {
@@ -601,7 +630,8 @@ static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
return dpage;
error:
- __free_page(rpage);
+ if (rpage)
+ __free_page(rpage);
return NULL;
}
@@ -627,12 +657,16 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args,
* unallocated pte_none() or read-only zero page.
*/
spage = migrate_pfn_to_page(*src);
+ if (WARN(spage && is_zone_device_page(spage),
+ "page already in device spage pfn: 0x%lx\n",
+ page_to_pfn(spage)))
+ continue;
dpage = dmirror_devmem_alloc_page(mdevice);
if (!dpage)
continue;
- rpage = dpage->zone_device_data;
+ rpage = BACKING_PAGE(dpage);
if (spage)
copy_highpage(rpage, spage);
else
@@ -646,6 +680,8 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args,
*/
rpage->zone_device_data = dmirror;
+ pr_debug("migrating from sys to dev pfn src: 0x%lx pfn dst: 0x%lx\n",
+ page_to_pfn(spage), page_to_pfn(dpage));
*dst = migrate_pfn(page_to_pfn(dpage)) |
MIGRATE_PFN_LOCKED;
if ((*src & MIGRATE_PFN_WRITE) ||
@@ -724,11 +760,7 @@ static int dmirror_migrate_finalize_and_map(struct migrate_vma *args,
if (!dpage)
continue;
- /*
- * Store the page that holds the data so the page table
- * doesn't have to deal with ZONE_DEVICE private pages.
- */
- entry = dpage->zone_device_data;
+ entry = BACKING_PAGE(dpage);
if (*dst & MIGRATE_PFN_WRITE)
entry = xa_tag_pointer(entry, DPT_XA_TAG_WRITE);
entry = xa_store(&dmirror->pt, pfn, entry, GFP_ATOMIC);
@@ -808,15 +840,124 @@ static int dmirror_exclusive(struct dmirror *dmirror,
return ret;
}
-static int dmirror_migrate(struct dmirror *dmirror,
- struct hmm_dmirror_cmd *cmd)
+static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args,
+ struct dmirror *dmirror)
+{
+ const unsigned long *src = args->src;
+ unsigned long *dst = args->dst;
+ unsigned long start = args->start;
+ unsigned long end = args->end;
+ unsigned long addr;
+
+ for (addr = start; addr < end; addr += PAGE_SIZE,
+ src++, dst++) {
+ struct page *dpage, *spage;
+
+ spage = migrate_pfn_to_page(*src);
+ if (!spage || !(*src & MIGRATE_PFN_MIGRATE))
+ continue;
+
+ if (WARN_ON(!is_dev_private_or_coherent_page(spage)))
+ continue;
+ spage = BACKING_PAGE(spage);
+ dpage = alloc_page_vma(GFP_HIGHUSER_MOVABLE, args->vma, addr);
+ if (!dpage)
+ continue;
+ pr_debug("migrating from dev to sys pfn src: 0x%lx pfn dst: 0x%lx\n",
+ page_to_pfn(spage), page_to_pfn(dpage));
+
+ lock_page(dpage);
+ xa_erase(&dmirror->pt, addr >> PAGE_SHIFT);
+ copy_highpage(dpage, spage);
+ *dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
+ if (*src & MIGRATE_PFN_WRITE)
+ *dst |= MIGRATE_PFN_WRITE;
+ }
+ return 0;
+}
+
+static unsigned long dmirror_successful_migrated_pages(struct migrate_vma *migrate)
+{
+ unsigned long cpages = 0;
+ unsigned long i;
+
+ for (i = 0; i < migrate->npages; i++) {
+ if (migrate->src[i] & MIGRATE_PFN_VALID &&
+ migrate->src[i] & MIGRATE_PFN_MIGRATE)
+ cpages++;
+ }
+ return cpages;
+}
+
+static int dmirror_migrate_to_system(struct dmirror *dmirror,
+ struct hmm_dmirror_cmd *cmd)
+{
+ unsigned long start, end, addr;
+ unsigned long size = cmd->npages << PAGE_SHIFT;
+ struct mm_struct *mm = dmirror->notifier.mm;
+ struct vm_area_struct *vma;
+ unsigned long src_pfns[64] = { 0 };
+ unsigned long dst_pfns[64] = { 0 };
+ struct migrate_vma args;
+ unsigned long next;
+ int ret;
+
+ start = cmd->addr;
+ end = start + size;
+ if (end < start)
+ return -EINVAL;
+
+ /* Since the mm is for the mirrored process, get a reference first. */
+ if (!mmget_not_zero(mm))
+ return -EINVAL;
+
+ cmd->cpages = 0;
+ mmap_read_lock(mm);
+ for (addr = start; addr < end; addr = next) {
+ vma = vma_lookup(mm, addr);
+ if (!vma || !(vma->vm_flags & VM_READ)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ next = min(end, addr + (ARRAY_SIZE(src_pfns) << PAGE_SHIFT));
+ if (next > vma->vm_end)
+ next = vma->vm_end;
+
+ args.vma = vma;
+ args.src = src_pfns;
+ args.dst = dst_pfns;
+ args.start = addr;
+ args.end = next;
+ args.pgmap_owner = dmirror->mdevice;
+ args.flags = dmirror_select_device(dmirror);
+
+ ret = migrate_vma_setup(&args);
+ if (ret)
+ goto out;
+
+ pr_debug("Migrating from device mem to sys mem\n");
+ dmirror_devmem_fault_alloc_and_copy(&args, dmirror);
+
+ migrate_vma_pages(&args);
+ cmd->cpages += dmirror_successful_migrated_pages(&args);
+ migrate_vma_finalize(&args);
+ }
+out:
+ mmap_read_unlock(mm);
+ mmput(mm);
+
+ return ret;
+}
+
+static int dmirror_migrate_to_device(struct dmirror *dmirror,
+ struct hmm_dmirror_cmd *cmd)
{
unsigned long start, end, addr;
unsigned long size = cmd->npages << PAGE_SHIFT;
struct mm_struct *mm = dmirror->notifier.mm;
struct vm_area_struct *vma;
- unsigned long src_pfns[64];
- unsigned long dst_pfns[64];
+ unsigned long src_pfns[64] = { 0 };
+ unsigned long dst_pfns[64] = { 0 };
struct dmirror_bounce bounce;
struct migrate_vma args;
unsigned long next;
@@ -853,6 +994,7 @@ static int dmirror_migrate(struct dmirror *dmirror,
if (ret)
goto out;
+ pr_debug("Migrating from sys mem to device mem\n");
dmirror_migrate_alloc_and_copy(&args, dmirror);
migrate_vma_pages(&args);
dmirror_migrate_finalize_and_map(&args, dmirror);
@@ -861,7 +1003,7 @@ static int dmirror_migrate(struct dmirror *dmirror,
mmap_read_unlock(mm);
mmput(mm);
- /* Return the migrated data for verification. */
+ /* Return the migrated data for verification. only for pages in device zone */
ret = dmirror_bounce_init(&bounce, start, size);
if (ret)
return ret;
@@ -898,12 +1040,22 @@ static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range,
}
page = hmm_pfn_to_page(entry);
- if (is_device_private_page(page)) {
- /* Is the page migrated to this device or some other? */
- if (dmirror->mdevice == dmirror_page_to_device(page))
+ if (is_dev_private_or_coherent_page(page)) {
+ /* Is page ZONE_DEVICE coherent? */
+ if (is_device_coherent_page(page)) {
+ if (dmirror->mdevice == dmirror_page_to_device(page))
+ *perm = HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL;
+ else
+ *perm = HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE;
+ /*
+ * Is page ZONE_DEVICE private migrated to
+ * this device or some other?
+ */
+ } else if (dmirror->mdevice == dmirror_page_to_device(page)) {
*perm = HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL;
- else
+ } else {
*perm = HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE;
+ }
} else if (is_zero_pfn(page_to_pfn(page)))
*perm = HMM_DMIRROR_PROT_ZERO;
else
@@ -1100,8 +1252,12 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp,
ret = dmirror_write(dmirror, &cmd);
break;
- case HMM_DMIRROR_MIGRATE:
- ret = dmirror_migrate(dmirror, &cmd);
+ case HMM_DMIRROR_MIGRATE_TO_DEV:
+ ret = dmirror_migrate_to_device(dmirror, &cmd);
+ break;
+
+ case HMM_DMIRROR_MIGRATE_TO_SYS:
+ ret = dmirror_migrate_to_system(dmirror, &cmd);
break;
case HMM_DMIRROR_EXCLUSIVE:
@@ -1142,14 +1298,13 @@ static const struct file_operations dmirror_fops = {
static void dmirror_devmem_free(struct page *page)
{
- struct page *rpage = page->zone_device_data;
+ struct page *rpage = BACKING_PAGE(page);
struct dmirror_device *mdevice;
- if (rpage)
+ if (rpage != page)
__free_page(rpage);
mdevice = dmirror_page_to_device(page);
-
spin_lock(&mdevice->lock);
mdevice->cfree++;
page->zone_device_data = mdevice->free_pages;
@@ -1157,43 +1312,11 @@ static void dmirror_devmem_free(struct page *page)
spin_unlock(&mdevice->lock);
}
-static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args,
- struct dmirror *dmirror)
-{
- const unsigned long *src = args->src;
- unsigned long *dst = args->dst;
- unsigned long start = args->start;
- unsigned long end = args->end;
- unsigned long addr;
-
- for (addr = start; addr < end; addr += PAGE_SIZE,
- src++, dst++) {
- struct page *dpage, *spage;
-
- spage = migrate_pfn_to_page(*src);
- if (!spage || !(*src & MIGRATE_PFN_MIGRATE))
- continue;
- spage = spage->zone_device_data;
-
- dpage = alloc_page_vma(GFP_HIGHUSER_MOVABLE, args->vma, addr);
- if (!dpage)
- continue;
-
- lock_page(dpage);
- xa_erase(&dmirror->pt, addr >> PAGE_SHIFT);
- copy_highpage(dpage, spage);
- *dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
- if (*src & MIGRATE_PFN_WRITE)
- *dst |= MIGRATE_PFN_WRITE;
- }
- return 0;
-}
-
static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf)
{
struct migrate_vma args;
- unsigned long src_pfns;
- unsigned long dst_pfns;
+ unsigned long src_pfns = 0;
+ unsigned long dst_pfns = 0;
struct page *rpage;
struct dmirror *dmirror;
vm_fault_t ret;
@@ -1213,7 +1336,7 @@ static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf)
args.src = &src_pfns;
args.dst = &dst_pfns;
args.pgmap_owner = dmirror->mdevice;
- args.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
+ args.flags = dmirror_select_device(dmirror);
if (migrate_vma_setup(&args))
return VM_FAULT_SIGBUS;
@@ -1292,6 +1415,12 @@ static int __init hmm_dmirror_init(void)
HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
dmirror_devices[ndevices++].zone_device_type =
HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
+ if (spm_addr_dev0 && spm_addr_dev1) {
+ dmirror_devices[ndevices++].zone_device_type =
+ HMM_DMIRROR_MEMORY_DEVICE_COHERENT;
+ dmirror_devices[ndevices++].zone_device_type =
+ HMM_DMIRROR_MEMORY_DEVICE_COHERENT;
+ }
for (id = 0; id < ndevices; id++) {
ret = dmirror_device_init(dmirror_devices + id, id);
if (ret)
@@ -1314,7 +1443,8 @@ static void __exit hmm_dmirror_exit(void)
int id;
for (id = 0; id < DMIRROR_NDEVICES; id++)
- dmirror_device_remove(dmirror_devices + id);
+ if (dmirror_devices[id].zone_device_type)
+ dmirror_device_remove(dmirror_devices + id);
unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES);
}
diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
index 625f3690d086..e190b2ab6f19 100644
--- a/lib/test_hmm_uapi.h
+++ b/lib/test_hmm_uapi.h
@@ -33,11 +33,12 @@ struct hmm_dmirror_cmd {
/* Expose the address space of the calling process through hmm device file */
#define HMM_DMIRROR_READ _IOWR('H', 0x00, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_WRITE _IOWR('H', 0x01, struct hmm_dmirror_cmd)
-#define HMM_DMIRROR_MIGRATE _IOWR('H', 0x02, struct hmm_dmirror_cmd)
-#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x03, struct hmm_dmirror_cmd)
-#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x04, struct hmm_dmirror_cmd)
-#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)
-#define HMM_DMIRROR_GET_MEM_DEV_TYPE _IOWR('H', 0x06, struct hmm_dmirror_cmd)
+#define HMM_DMIRROR_MIGRATE_TO_DEV _IOWR('H', 0x02, struct hmm_dmirror_cmd)
+#define HMM_DMIRROR_MIGRATE_TO_SYS _IOWR('H', 0x03, struct hmm_dmirror_cmd)
+#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x04, struct hmm_dmirror_cmd)
+#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)
+#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x06, struct hmm_dmirror_cmd)
+#define HMM_DMIRROR_GET_MEM_DEV_TYPE _IOWR('H', 0x07, struct hmm_dmirror_cmd)
/*
* Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
@@ -52,6 +53,8 @@ struct hmm_dmirror_cmd {
* device the ioctl() is made
* HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some
* other device
+ * HMM_DMIRROR_PROT_DEV_COHERENT: Migrate device coherent page on the device
+ * the ioctl() is made
*/
enum {
HMM_DMIRROR_PROT_ERROR = 0xFF,
@@ -63,6 +66,8 @@ enum {
HMM_DMIRROR_PROT_ZERO = 0x10,
HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20,
HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30,
+ HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL = 0x40,
+ HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE = 0x50,
};
enum {
--
2.32.0
Add two more parameters to set spm_addr_dev0 & spm_addr_dev1
addresses. These two parameters configure the start SP
addresses for each device in test_hmm driver.
Consequently, this configures zone device type as coherent.
Signed-off-by: Alex Sierra <[email protected]>
Reviewed-by: Alistair Popple <[email protected]>
---
v2:
Add more mknods for device coherent type. These are represented under
/dev/hmm_mirror2 and /dev/hmm_mirror3, only in case they have created
at probing the hmm-test driver.
---
tools/testing/selftests/vm/test_hmm.sh | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftests/vm/test_hmm.sh
index 0647b525a625..539c9371e592 100755
--- a/tools/testing/selftests/vm/test_hmm.sh
+++ b/tools/testing/selftests/vm/test_hmm.sh
@@ -40,11 +40,26 @@ check_test_requirements()
load_driver()
{
- modprobe $DRIVER > /dev/null 2>&1
+ if [ $# -eq 0 ]; then
+ modprobe $DRIVER > /dev/null 2>&1
+ else
+ if [ $# -eq 2 ]; then
+ modprobe $DRIVER spm_addr_dev0=$1 spm_addr_dev1=$2
+ > /dev/null 2>&1
+ else
+ echo "Missing module parameters. Make sure pass"\
+ "spm_addr_dev0 and spm_addr_dev1"
+ usage
+ fi
+ fi
if [ $? == 0 ]; then
major=$(awk "\$2==\"HMM_DMIRROR\" {print \$1}" /proc/devices)
mknod /dev/hmm_dmirror0 c $major 0
mknod /dev/hmm_dmirror1 c $major 1
+ if [ $# -eq 2 ]; then
+ mknod /dev/hmm_dmirror2 c $major 2
+ mknod /dev/hmm_dmirror3 c $major 3
+ fi
fi
}
@@ -58,7 +73,7 @@ run_smoke()
{
echo "Running smoke test. Note, this test provides basic coverage."
- load_driver
+ load_driver $1 $2
$(dirname "${BASH_SOURCE[0]}")/hmm-tests
unload_driver
}
@@ -75,6 +90,9 @@ usage()
echo "# Smoke testing"
echo "./${TEST_NAME}.sh smoke"
echo
+ echo "# Smoke testing with SPM enabled"
+ echo "./${TEST_NAME}.sh smoke <spm_addr_dev0> <spm_addr_dev1>"
+ echo
exit 0
}
@@ -84,7 +102,7 @@ function run_test()
usage
else
if [ "$1" = "smoke" ]; then
- run_smoke
+ run_smoke $2 $3
else
usage
fi
--
2.32.0
On Wed, 26 Jan 2022 21:09:39 -0600 Alex Sierra <[email protected]> wrote:
> This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory
> owned by a device that can be mapped into CPU page tables like
> MEMORY_DEVICE_GENERIC and can also be migrated like
> MEMORY_DEVICE_PRIVATE.
Some more reviewer input appears to be desirable here.
I was going to tentatively add it to -mm and -next, but problems.
5.17-rc1's mm/migrate.c:migrate_vma_check_page() is rather different
from the tree you patched. Please redo, refresh and resend?
Andrew,
We're somehow new on this procedure. Are you referring to rebase this
patch series to
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
<5.17-rc1 tag>?
Regards,
Alex Sierra
Alex Deucher,
Just a quick heads up. This patch series contains changes to the amdgpu
driver which we're
planning to merge through Andrew's tree, If that's ok with you.
Regards,
Alex Sierra
On 1/27/2022 4:32 PM, Andrew Morton wrote:
> On Wed, 26 Jan 2022 21:09:39 -0600 Alex Sierra <[email protected]> wrote:
>
>> This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory
>> owned by a device that can be mapped into CPU page tables like
>> MEMORY_DEVICE_GENERIC and can also be migrated like
>> MEMORY_DEVICE_PRIVATE.
> Some more reviewer input appears to be desirable here.
>
> I was going to tentatively add it to -mm and -next, but problems.
> 5.17-rc1's mm/migrate.c:migrate_vma_check_page() is rather different
> from the tree you patched. Please redo, refresh and resend?
>
On Thursday, 27 January 2022 2:09:41 PM AEDT Alex Sierra wrote:
[...]
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 277562cd4cf5..2b3375e165b1 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -2340,8 +2340,6 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
> if (is_writable_device_private_entry(entry))
> mpfn |= MIGRATE_PFN_WRITE;
> } else {
> - if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
> - goto next;
This isn't correct as it allows zero pfn pages to be selected for migration
when they shouldn't be (ie. because MIGRATE_VMA_SELECT_SYSTEM isn't specified).
> pfn = pte_pfn(pte);
> if (is_zero_pfn(pfn)) {
> mpfn = MIGRATE_PFN_MIGRATE;
> @@ -2349,6 +2347,13 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
> goto next;
> }
> page = vm_normal_page(migrate->vma, addr, pte);
> + if (page && !is_zone_device_page(page) &&
> + !(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM))
> + goto next;
> + if (page && is_device_coherent_page(page) &&
> + (!(migrate->flags & MIGRATE_VMA_SELECT_DEVICE_COHERENT) ||
> + page->pgmap->owner != migrate->pgmap_owner))
> + goto next;
> mpfn = migrate_pfn(pfn) | MIGRATE_PFN_MIGRATE;
> mpfn |= pte_write(pte) ? MIGRATE_PFN_WRITE : 0;
> }
>
On Thursday, 27 January 2022 2:09:42 PM AEDT Alex Sierra wrote:
> Avoid long term pinning for Coherent device type pages. This could
> interfere with their own device memory manager. For now, we are just
> returning error for PIN_LONGTERM Coherent device type pages. Eventually,
> these type of pages will get migrated to system memory, once the device
> migration pages support is added.
>
> Signed-off-by: Alex Sierra <[email protected]>
> ---
> mm/gup.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index 886d6148d3d0..5291d7221826 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1720,6 +1720,12 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages,
> * If we get a movable page, since we are going to be pinning
> * these entries, try to move them out if possible.
> */
> + if (is_dev_private_or_coherent_page(head)) {
> + WARN_ON_ONCE(is_device_private_page(head));
> + ret = -EFAULT;
> + goto unpin_pages;
> + }
> +
> if (!is_pinnable_page(head)) {
> if (PageHuge(head)) {
> if (!isolate_huge_page(head, &movable_page_list))
> @@ -1750,6 +1756,7 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages,
> if (list_empty(&movable_page_list) && !isolation_error_count)
> return nr_pages;
>
> +unpin_pages:
> if (gup_flags & FOLL_PIN) {
> unpin_user_pages(pages, nr_pages);
> } else {
If there is a mix of ZONE_MOVABLE and device pages the return value (ret) will
be subsequently lost here:
if (!list_empty(&movable_page_list)) {
ret = migrate_pages(&movable_page_list, alloc_migration_target,
NULL, (unsigned long)&mtc, MIGRATE_SYNC,
MR_LONGTERM_PIN, NULL);
if (ret && !list_empty(&movable_page_list))
putback_movable_pages(&movable_page_list);
}
Which won't actually cause any problems, but it will lead to the GUP getting
retried unnecessarily. I do still intend to address this with a series to
migrate pages instead though, so I think this is ok for now as it's an unlikely
corner case anyway. Therefore feel tree to add the below when you repost:
Reviewed-by: Alistair Poppple <[email protected]>
On Thursday, 27 January 2022 2:09:43 PM AEDT Alex Sierra wrote:
[...]
> @@ -984,3 +990,4 @@ int svm_migrate_init(struct amdgpu_device *adev)
>
> return 0;
> }
> +
>
git-am complained about this when I applied the series. Given you have to
rebase anyway it would be worth fixing this.
Reviewed-by: Alistair Popple <[email protected]>
On Thursday, 27 January 2022 2:09:45 PM AEDT Alex Sierra wrote:
> new ioctl cmd added to query zone device type. This will be
> used once the test_hmm adds zone device coherent type.
>
> Signed-off-by: Alex Sierra <[email protected]>
> ---
> lib/test_hmm.c | 23 +++++++++++++++++++++--
> lib/test_hmm_uapi.h | 8 ++++++++
> 2 files changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/lib/test_hmm.c b/lib/test_hmm.c
> index c259842f6d44..fb1fa7c6fa98 100644
> --- a/lib/test_hmm.c
> +++ b/lib/test_hmm.c
> @@ -84,6 +84,7 @@ struct dmirror_chunk {
> struct dmirror_device {
> struct cdev cdevice;
> struct hmm_devmem *devmem;
> + unsigned int zone_device_type;
>
> unsigned int devmem_capacity;
> unsigned int devmem_count;
> @@ -1025,6 +1026,15 @@ static int dmirror_snapshot(struct dmirror *dmirror,
> return ret;
> }
>
> +static int dmirror_get_device_type(struct dmirror *dmirror,
> + struct hmm_dmirror_cmd *cmd)
> +{
> + mutex_lock(&dmirror->mutex);
> + cmd->zone_device_type = dmirror->mdevice->zone_device_type;
> + mutex_unlock(&dmirror->mutex);
> +
> + return 0;
> +}
> static long dmirror_fops_unlocked_ioctl(struct file *filp,
> unsigned int command,
> unsigned long arg)
> @@ -1075,6 +1085,9 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp,
> ret = dmirror_snapshot(dmirror, &cmd);
> break;
>
> + case HMM_DMIRROR_GET_MEM_DEV_TYPE:
> + ret = dmirror_get_device_type(dmirror, &cmd);
> + break;
> default:
> return -EINVAL;
> }
> @@ -1235,14 +1248,20 @@ static void dmirror_device_remove(struct dmirror_device *mdevice)
> static int __init hmm_dmirror_init(void)
> {
> int ret;
> - int id;
> + int id = 0;
> + int ndevices = 0;
>
> ret = alloc_chrdev_region(&dmirror_dev, 0, DMIRROR_NDEVICES,
> "HMM_DMIRROR");
> if (ret)
> goto err_unreg;
>
> - for (id = 0; id < DMIRROR_NDEVICES; id++) {
> + memset(dmirror_devices, 0, DMIRROR_NDEVICES * sizeof(dmirror_devices[0]));
> + dmirror_devices[ndevices++].zone_device_type =
> + HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
> + dmirror_devices[ndevices++].zone_device_type =
> + HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
> + for (id = 0; id < ndevices; id++) {
> ret = dmirror_device_init(dmirror_devices + id, id);
> if (ret)
> goto err_chrdev;
> diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
> index f14dea5dcd06..17f842f1aa02 100644
> --- a/lib/test_hmm_uapi.h
> +++ b/lib/test_hmm_uapi.h
> @@ -19,6 +19,7 @@
> * @npages: (in) number of pages to read/write
> * @cpages: (out) number of pages copied
> * @faults: (out) number of device page faults seen
> + * @zone_device_type: (out) zone device memory type
> */
> struct hmm_dmirror_cmd {
> __u64 addr;
> @@ -26,6 +27,7 @@ struct hmm_dmirror_cmd {
> __u64 npages;
> __u64 cpages;
> __u64 faults;
> + __u64 zone_device_type;
> };
>
> /* Expose the address space of the calling process through hmm device file */
> @@ -35,6 +37,7 @@ struct hmm_dmirror_cmd {
> #define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x03, struct hmm_dmirror_cmd)
> #define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x04, struct hmm_dmirror_cmd)
> #define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)
> +#define HMM_DMIRROR_GET_MEM_DEV_TYPE _IOWR('H', 0x06, struct hmm_dmirror_cmd)
>
> /*
> * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
> @@ -62,4 +65,9 @@ enum {
> HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30,
> };
>
> +enum {
> + /* 0 is reserved to catch uninitialized type fields */
> + HMM_DMIRROR_MEMORY_DEVICE_PRIVATE = 1,
> +};
> +
> #endif /* _LIB_TEST_HMM_UAPI_H */
>
Thanks for the updates, looks good now.
Reviewed-by: Alistair Popple <[email protected]>
On Thursday, 27 January 2022 2:09:46 PM AEDT Alex Sierra wrote:
> In order to configure device coherent in test_hmm, two module parameters
> should be passed, which correspond to the SP start address of each
> device (2) spm_addr_dev0 & spm_addr_dev1. If no parameters are passed,
> private device type is configured.
>
> Signed-off-by: Alex Sierra <[email protected]>
> ---
> lib/test_hmm.c | 73 ++++++++++++++++++++++++++++++++-------------
> lib/test_hmm_uapi.h | 1 +
> 2 files changed, 53 insertions(+), 21 deletions(-)
>
> diff --git a/lib/test_hmm.c b/lib/test_hmm.c
> index fb1fa7c6fa98..6f068f7c4ee3 100644
> --- a/lib/test_hmm.c
> +++ b/lib/test_hmm.c
> @@ -34,6 +34,16 @@
> #define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U)
> #define DEVMEM_CHUNKS_RESERVE 16
>
> +static unsigned long spm_addr_dev0;
> +module_param(spm_addr_dev0, long, 0644);
> +MODULE_PARM_DESC(spm_addr_dev0,
> + "Specify start address for SPM (special purpose memory) used for device 0. By setting this Coherent device type will be used. Make sure spm_addr_dev1 is set too. Minimum SPM size should be DEVMEM_CHUNK_SIZE.");
> +
> +static unsigned long spm_addr_dev1;
> +module_param(spm_addr_dev1, long, 0644);
> +MODULE_PARM_DESC(spm_addr_dev1,
> + "Specify start address for SPM (special purpose memory) used for device 1. By setting this Coherent device type will be used. Make sure spm_addr_dev0 is set too. Minimum SPM size should be DEVMEM_CHUNK_SIZE.");
> +
> static const struct dev_pagemap_ops dmirror_devmem_ops;
> static const struct mmu_interval_notifier_ops dmirror_min_ops;
> static dev_t dmirror_dev;
> @@ -452,28 +462,44 @@ static int dmirror_write(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd)
> return ret;
> }
>
> -static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
> +static int dmirror_allocate_chunk(struct dmirror_device *mdevice,
> struct page **ppage)
> {
> struct dmirror_chunk *devmem;
> - struct resource *res;
> + struct resource *res = NULL;
> unsigned long pfn;
> unsigned long pfn_first;
> unsigned long pfn_last;
> void *ptr;
> + int ret = -ENOMEM;
>
> devmem = kzalloc(sizeof(*devmem), GFP_KERNEL);
> if (!devmem)
> - return false;
> + return ret;
>
> - res = request_free_mem_region(&iomem_resource, DEVMEM_CHUNK_SIZE,
> - "hmm_dmirror");
> - if (IS_ERR(res))
> + switch (mdevice->zone_device_type) {
> + case HMM_DMIRROR_MEMORY_DEVICE_PRIVATE:
> + res = request_free_mem_region(&iomem_resource, DEVMEM_CHUNK_SIZE,
> + "hmm_dmirror");
> + if (IS_ERR_OR_NULL(res))
> + goto err_devmem;
> + devmem->pagemap.range.start = res->start;
> + devmem->pagemap.range.end = res->end;
> + devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
> + break;
> + case HMM_DMIRROR_MEMORY_DEVICE_COHERENT:
> + devmem->pagemap.range.start = (MINOR(mdevice->cdevice.dev) - 2) ?
> + spm_addr_dev0 :
> + spm_addr_dev1;
> + devmem->pagemap.range.end = devmem->pagemap.range.start +
> + DEVMEM_CHUNK_SIZE - 1;
> + devmem->pagemap.type = MEMORY_DEVICE_COHERENT;
> + break;
> + default:
> + ret = -EINVAL;
> goto err_devmem;
> + }
>
> - devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
> - devmem->pagemap.range.start = res->start;
> - devmem->pagemap.range.end = res->end;
> devmem->pagemap.nr_range = 1;
> devmem->pagemap.ops = &dmirror_devmem_ops;
> devmem->pagemap.owner = mdevice;
> @@ -494,10 +520,14 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
> mdevice->devmem_capacity = new_capacity;
> mdevice->devmem_chunks = new_chunks;
> }
> -
> ptr = memremap_pages(&devmem->pagemap, numa_node_id());
> - if (IS_ERR(ptr))
> + if (IS_ERR_OR_NULL(ptr)) {
> + if (ptr)
> + ret = PTR_ERR(ptr);
> + else
> + ret = -EFAULT;
> goto err_release;
> + }
>
> devmem->mdevice = mdevice;
> pfn_first = devmem->pagemap.range.start >> PAGE_SHIFT;
> @@ -526,15 +556,17 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
> }
> spin_unlock(&mdevice->lock);
>
> - return true;
> + return 0;
>
> err_release:
> mutex_unlock(&mdevice->devmem_lock);
> - release_mem_region(devmem->pagemap.range.start, range_len(&devmem->pagemap.range));
> + if (res && devmem->pagemap.type == MEMORY_DEVICE_PRIVATE)
> + release_mem_region(devmem->pagemap.range.start,
> + range_len(&devmem->pagemap.range));
> err_devmem:
> kfree(devmem);
>
> - return false;
> + return ret;
> }
>
> static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
> @@ -559,7 +591,7 @@ static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
> spin_unlock(&mdevice->lock);
> } else {
> spin_unlock(&mdevice->lock);
> - if (!dmirror_allocate_chunk(mdevice, &dpage))
> + if (dmirror_allocate_chunk(mdevice, &dpage))
> goto error;
> }
>
> @@ -1219,10 +1251,8 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id)
> if (ret)
> return ret;
>
> - /* Build a list of free ZONE_DEVICE private struct pages */
> - dmirror_allocate_chunk(mdevice, NULL);
> -
> - return 0;
> + /* Build a list of free ZONE_DEVICE struct pages */
> + return dmirror_allocate_chunk(mdevice, NULL);
> }
>
> static void dmirror_device_remove(struct dmirror_device *mdevice)
> @@ -1235,8 +1265,9 @@ static void dmirror_device_remove(struct dmirror_device *mdevice)
> mdevice->devmem_chunks[i];
>
> memunmap_pages(&devmem->pagemap);
> - release_mem_region(devmem->pagemap.range.start,
> - range_len(&devmem->pagemap.range));
> + if (devmem->pagemap.type == MEMORY_DEVICE_PRIVATE)
> + release_mem_region(devmem->pagemap.range.start,
> + range_len(&devmem->pagemap.range));
> kfree(devmem);
> }
> kfree(mdevice->devmem_chunks);
> diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
> index 17f842f1aa02..625f3690d086 100644
> --- a/lib/test_hmm_uapi.h
> +++ b/lib/test_hmm_uapi.h
> @@ -68,6 +68,7 @@ enum {
> enum {
> /* 0 is reserved to catch uninitialized type fields */
> HMM_DMIRROR_MEMORY_DEVICE_PRIVATE = 1,
> + HMM_DMIRROR_MEMORY_DEVICE_COHERENT,
> };
>
> #endif /* _LIB_TEST_HMM_UAPI_H */
>
I haven't tested the change which checks that pages migrated back to sysmem,
but it looks ok so:
Reviewed-by: Alistair Popple <[email protected]>
On Thursday, 27 January 2022 2:09:47 PM AEDT Alex Sierra wrote:
> Device Coherent type uses device memory that is coherently accesible by
> the CPU. This could be shown as SP (special purpose) memory range
> at the BIOS-e820 memory enumeration. If no SP memory is supported in
> system, this could be faked by setting CONFIG_EFI_FAKE_MEMMAP.
>
> Currently, test_hmm only supports two different SP ranges of at least
> 256MB size. This could be specified in the kernel parameter variable
> efi_fake_mem. Ex. Two SP ranges of 1GB starting at 0x100000000 &
> 0x140000000 physical address. Ex.
> efi_fake_mem=1G@0x100000000:0x40000,1G@0x140000000:0x40000
>
> Private and coherent device mirror instances can be created in the same
> probed. This is done by passing the module parameters spm_addr_dev0 &
> spm_addr_dev1. In this case, it will create four instances of
> device_mirror. The first two correspond to private device type, the
> last two to coherent type. Then, they can be easily accessed from user
> space through /dev/hmm_mirror<num_device>. Usually num_device 0 and 1
> are for private, and 2 and 3 for coherent types. If no module
> parameters are passed, two instances of private type device_mirror will
> be created only.
>
> Signed-off-by: Alex Sierra <[email protected]>
> ---
> v4:
> Return number of coherent device pages successfully migrated to system.
> This is returned at cmd->cpages.
> ---
> lib/test_hmm.c | 260 +++++++++++++++++++++++++++++++++-----------
> lib/test_hmm_uapi.h | 15 ++-
> 2 files changed, 205 insertions(+), 70 deletions(-)
>
> diff --git a/lib/test_hmm.c b/lib/test_hmm.c
> index 6f068f7c4ee3..850d5331e370 100644
> --- a/lib/test_hmm.c
> +++ b/lib/test_hmm.c
> @@ -29,11 +29,22 @@
>
> #include "test_hmm_uapi.h"
>
> -#define DMIRROR_NDEVICES 2
> +#define DMIRROR_NDEVICES 4
> #define DMIRROR_RANGE_FAULT_TIMEOUT 1000
> #define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U)
> #define DEVMEM_CHUNKS_RESERVE 16
>
> +/*
> + * For device_private pages, dpage is just a dummy struct page
> + * representing a piece of device memory. dmirror_devmem_alloc_page
> + * allocates a real system memory page as backing storage to fake a
> + * real device. zone_device_data points to that backing page. But
> + * for device_coherent memory, the struct page represents real
> + * physical CPU-accessible memory that we can use directly.
> + */
> +#define BACKING_PAGE(page) (is_device_private_page((page)) ? \
> + (page)->zone_device_data : (page))
> +
> static unsigned long spm_addr_dev0;
> module_param(spm_addr_dev0, long, 0644);
> MODULE_PARM_DESC(spm_addr_dev0,
> @@ -122,6 +133,21 @@ static int dmirror_bounce_init(struct dmirror_bounce *bounce,
> return 0;
> }
>
> +static bool dmirror_is_private_zone(struct dmirror_device *mdevice)
> +{
> + return (mdevice->zone_device_type ==
> + HMM_DMIRROR_MEMORY_DEVICE_PRIVATE) ? true : false;
> +}
> +
> +static enum migrate_vma_direction
> + dmirror_select_device(struct dmirror *dmirror)
> +{
> + return (dmirror->mdevice->zone_device_type ==
> + HMM_DMIRROR_MEMORY_DEVICE_PRIVATE) ?
> + MIGRATE_VMA_SELECT_DEVICE_PRIVATE :
> + MIGRATE_VMA_SELECT_DEVICE_COHERENT;
> +}
> +
> static void dmirror_bounce_fini(struct dmirror_bounce *bounce)
> {
> vfree(bounce->ptr);
> @@ -572,16 +598,19 @@ static int dmirror_allocate_chunk(struct dmirror_device *mdevice,
> static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
> {
> struct page *dpage = NULL;
> - struct page *rpage;
> + struct page *rpage = NULL;
>
> /*
> - * This is a fake device so we alloc real system memory to store
> - * our device memory.
> + * For ZONE_DEVICE private type, this is a fake device so we alloc real
> + * system memory to store our device memory.
> + * For ZONE_DEVICE coherent type we use the actual dpage to store the data
> + * and ignore rpage.
> */
> - rpage = alloc_page(GFP_HIGHUSER);
> - if (!rpage)
> - return NULL;
> -
> + if (dmirror_is_private_zone(mdevice)) {
> + rpage = alloc_page(GFP_HIGHUSER);
> + if (!rpage)
> + return NULL;
> + }
> spin_lock(&mdevice->lock);
>
> if (mdevice->free_pages) {
> @@ -601,7 +630,8 @@ static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
> return dpage;
>
> error:
> - __free_page(rpage);
> + if (rpage)
> + __free_page(rpage);
> return NULL;
> }
>
> @@ -627,12 +657,16 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args,
> * unallocated pte_none() or read-only zero page.
> */
> spage = migrate_pfn_to_page(*src);
> + if (WARN(spage && is_zone_device_page(spage),
> + "page already in device spage pfn: 0x%lx\n",
> + page_to_pfn(spage)))
> + continue;
>
> dpage = dmirror_devmem_alloc_page(mdevice);
> if (!dpage)
> continue;
>
> - rpage = dpage->zone_device_data;
> + rpage = BACKING_PAGE(dpage);
> if (spage)
> copy_highpage(rpage, spage);
> else
> @@ -646,6 +680,8 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args,
> */
> rpage->zone_device_data = dmirror;
>
> + pr_debug("migrating from sys to dev pfn src: 0x%lx pfn dst: 0x%lx\n",
> + page_to_pfn(spage), page_to_pfn(dpage));
> *dst = migrate_pfn(page_to_pfn(dpage)) |
> MIGRATE_PFN_LOCKED;
> if ((*src & MIGRATE_PFN_WRITE) ||
> @@ -724,11 +760,7 @@ static int dmirror_migrate_finalize_and_map(struct migrate_vma *args,
> if (!dpage)
> continue;
>
> - /*
> - * Store the page that holds the data so the page table
> - * doesn't have to deal with ZONE_DEVICE private pages.
> - */
> - entry = dpage->zone_device_data;
> + entry = BACKING_PAGE(dpage);
> if (*dst & MIGRATE_PFN_WRITE)
> entry = xa_tag_pointer(entry, DPT_XA_TAG_WRITE);
> entry = xa_store(&dmirror->pt, pfn, entry, GFP_ATOMIC);
> @@ -808,15 +840,124 @@ static int dmirror_exclusive(struct dmirror *dmirror,
> return ret;
> }
>
> -static int dmirror_migrate(struct dmirror *dmirror,
> - struct hmm_dmirror_cmd *cmd)
> +static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args,
> + struct dmirror *dmirror)
> +{
> + const unsigned long *src = args->src;
> + unsigned long *dst = args->dst;
> + unsigned long start = args->start;
> + unsigned long end = args->end;
> + unsigned long addr;
> +
> + for (addr = start; addr < end; addr += PAGE_SIZE,
> + src++, dst++) {
> + struct page *dpage, *spage;
> +
> + spage = migrate_pfn_to_page(*src);
> + if (!spage || !(*src & MIGRATE_PFN_MIGRATE))
> + continue;
> +
> + if (WARN_ON(!is_dev_private_or_coherent_page(spage)))
> + continue;
> + spage = BACKING_PAGE(spage);
> + dpage = alloc_page_vma(GFP_HIGHUSER_MOVABLE, args->vma, addr);
> + if (!dpage)
> + continue;
> + pr_debug("migrating from dev to sys pfn src: 0x%lx pfn dst: 0x%lx\n",
> + page_to_pfn(spage), page_to_pfn(dpage));
> +
> + lock_page(dpage);
> + xa_erase(&dmirror->pt, addr >> PAGE_SHIFT);
> + copy_highpage(dpage, spage);
> + *dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
> + if (*src & MIGRATE_PFN_WRITE)
> + *dst |= MIGRATE_PFN_WRITE;
> + }
> + return 0;
> +}
> +
> +static unsigned long dmirror_successful_migrated_pages(struct migrate_vma *migrate)
> +{
> + unsigned long cpages = 0;
> + unsigned long i;
> +
> + for (i = 0; i < migrate->npages; i++) {
> + if (migrate->src[i] & MIGRATE_PFN_VALID &&
> + migrate->src[i] & MIGRATE_PFN_MIGRATE)
> + cpages++;
> + }
> + return cpages;
> +}
> +
> +static int dmirror_migrate_to_system(struct dmirror *dmirror,
> + struct hmm_dmirror_cmd *cmd)
> +{
> + unsigned long start, end, addr;
> + unsigned long size = cmd->npages << PAGE_SHIFT;
> + struct mm_struct *mm = dmirror->notifier.mm;
> + struct vm_area_struct *vma;
> + unsigned long src_pfns[64] = { 0 };
> + unsigned long dst_pfns[64] = { 0 };
> + struct migrate_vma args;
> + unsigned long next;
> + int ret;
> +
> + start = cmd->addr;
> + end = start + size;
> + if (end < start)
> + return -EINVAL;
> +
> + /* Since the mm is for the mirrored process, get a reference first. */
> + if (!mmget_not_zero(mm))
> + return -EINVAL;
> +
> + cmd->cpages = 0;
> + mmap_read_lock(mm);
> + for (addr = start; addr < end; addr = next) {
> + vma = vma_lookup(mm, addr);
> + if (!vma || !(vma->vm_flags & VM_READ)) {
> + ret = -EINVAL;
> + goto out;
> + }
> + next = min(end, addr + (ARRAY_SIZE(src_pfns) << PAGE_SHIFT));
> + if (next > vma->vm_end)
> + next = vma->vm_end;
> +
> + args.vma = vma;
> + args.src = src_pfns;
> + args.dst = dst_pfns;
> + args.start = addr;
> + args.end = next;
> + args.pgmap_owner = dmirror->mdevice;
> + args.flags = dmirror_select_device(dmirror);
> +
> + ret = migrate_vma_setup(&args);
> + if (ret)
> + goto out;
> +
> + pr_debug("Migrating from device mem to sys mem\n");
> + dmirror_devmem_fault_alloc_and_copy(&args, dmirror);
> +
> + migrate_vma_pages(&args);
> + cmd->cpages += dmirror_successful_migrated_pages(&args);
> + migrate_vma_finalize(&args);
> + }
> +out:
> + mmap_read_unlock(mm);
> + mmput(mm);
> +
> + return ret;
> +}
> +
> +static int dmirror_migrate_to_device(struct dmirror *dmirror,
> + struct hmm_dmirror_cmd *cmd)
> {
> unsigned long start, end, addr;
> unsigned long size = cmd->npages << PAGE_SHIFT;
> struct mm_struct *mm = dmirror->notifier.mm;
> struct vm_area_struct *vma;
> - unsigned long src_pfns[64];
> - unsigned long dst_pfns[64];
> + unsigned long src_pfns[64] = { 0 };
> + unsigned long dst_pfns[64] = { 0 };
> struct dmirror_bounce bounce;
> struct migrate_vma args;
> unsigned long next;
> @@ -853,6 +994,7 @@ static int dmirror_migrate(struct dmirror *dmirror,
> if (ret)
> goto out;
>
> + pr_debug("Migrating from sys mem to device mem\n");
> dmirror_migrate_alloc_and_copy(&args, dmirror);
> migrate_vma_pages(&args);
> dmirror_migrate_finalize_and_map(&args, dmirror);
> @@ -861,7 +1003,7 @@ static int dmirror_migrate(struct dmirror *dmirror,
> mmap_read_unlock(mm);
> mmput(mm);
>
> - /* Return the migrated data for verification. */
> + /* Return the migrated data for verification. only for pages in device zone */
> ret = dmirror_bounce_init(&bounce, start, size);
> if (ret)
> return ret;
> @@ -898,12 +1040,22 @@ static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range,
> }
>
> page = hmm_pfn_to_page(entry);
> - if (is_device_private_page(page)) {
> - /* Is the page migrated to this device or some other? */
> - if (dmirror->mdevice == dmirror_page_to_device(page))
> + if (is_dev_private_or_coherent_page(page)) {
> + /* Is page ZONE_DEVICE coherent? */
> + if (is_device_coherent_page(page)) {
> + if (dmirror->mdevice == dmirror_page_to_device(page))
> + *perm = HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL;
> + else
> + *perm = HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE;
> + /*
> + * Is page ZONE_DEVICE private migrated to
> + * this device or some other?
> + */
> + } else if (dmirror->mdevice == dmirror_page_to_device(page)) {
> *perm = HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL;
> - else
> + } else {
> *perm = HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE;
> + }
> } else if (is_zero_pfn(page_to_pfn(page)))
> *perm = HMM_DMIRROR_PROT_ZERO;
> else
> @@ -1100,8 +1252,12 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp,
> ret = dmirror_write(dmirror, &cmd);
> break;
>
> - case HMM_DMIRROR_MIGRATE:
> - ret = dmirror_migrate(dmirror, &cmd);
> + case HMM_DMIRROR_MIGRATE_TO_DEV:
> + ret = dmirror_migrate_to_device(dmirror, &cmd);
> + break;
> +
> + case HMM_DMIRROR_MIGRATE_TO_SYS:
> + ret = dmirror_migrate_to_system(dmirror, &cmd);
> break;
>
> case HMM_DMIRROR_EXCLUSIVE:
> @@ -1142,14 +1298,13 @@ static const struct file_operations dmirror_fops = {
>
> static void dmirror_devmem_free(struct page *page)
> {
> - struct page *rpage = page->zone_device_data;
> + struct page *rpage = BACKING_PAGE(page);
> struct dmirror_device *mdevice;
>
> - if (rpage)
> + if (rpage != page)
> __free_page(rpage);
>
> mdevice = dmirror_page_to_device(page);
> -
> spin_lock(&mdevice->lock);
> mdevice->cfree++;
> page->zone_device_data = mdevice->free_pages;
> @@ -1157,43 +1312,11 @@ static void dmirror_devmem_free(struct page *page)
> spin_unlock(&mdevice->lock);
> }
>
> -static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args,
> - struct dmirror *dmirror)
> -{
> - const unsigned long *src = args->src;
> - unsigned long *dst = args->dst;
> - unsigned long start = args->start;
> - unsigned long end = args->end;
> - unsigned long addr;
> -
> - for (addr = start; addr < end; addr += PAGE_SIZE,
> - src++, dst++) {
> - struct page *dpage, *spage;
> -
> - spage = migrate_pfn_to_page(*src);
> - if (!spage || !(*src & MIGRATE_PFN_MIGRATE))
> - continue;
> - spage = spage->zone_device_data;
> -
> - dpage = alloc_page_vma(GFP_HIGHUSER_MOVABLE, args->vma, addr);
> - if (!dpage)
> - continue;
> -
> - lock_page(dpage);
> - xa_erase(&dmirror->pt, addr >> PAGE_SHIFT);
> - copy_highpage(dpage, spage);
> - *dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
> - if (*src & MIGRATE_PFN_WRITE)
> - *dst |= MIGRATE_PFN_WRITE;
> - }
> - return 0;
> -}
> -
> static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf)
> {
> struct migrate_vma args;
> - unsigned long src_pfns;
> - unsigned long dst_pfns;
> + unsigned long src_pfns = 0;
> + unsigned long dst_pfns = 0;
> struct page *rpage;
> struct dmirror *dmirror;
> vm_fault_t ret;
> @@ -1213,7 +1336,7 @@ static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf)
> args.src = &src_pfns;
> args.dst = &dst_pfns;
> args.pgmap_owner = dmirror->mdevice;
> - args.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
> + args.flags = dmirror_select_device(dmirror);
>
> if (migrate_vma_setup(&args))
> return VM_FAULT_SIGBUS;
> @@ -1292,6 +1415,12 @@ static int __init hmm_dmirror_init(void)
> HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
> dmirror_devices[ndevices++].zone_device_type =
> HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
> + if (spm_addr_dev0 && spm_addr_dev1) {
> + dmirror_devices[ndevices++].zone_device_type =
> + HMM_DMIRROR_MEMORY_DEVICE_COHERENT;
> + dmirror_devices[ndevices++].zone_device_type =
> + HMM_DMIRROR_MEMORY_DEVICE_COHERENT;
> + }
> for (id = 0; id < ndevices; id++) {
> ret = dmirror_device_init(dmirror_devices + id, id);
> if (ret)
> @@ -1314,7 +1443,8 @@ static void __exit hmm_dmirror_exit(void)
> int id;
>
> for (id = 0; id < DMIRROR_NDEVICES; id++)
> - dmirror_device_remove(dmirror_devices + id);
> + if (dmirror_devices[id].zone_device_type)
> + dmirror_device_remove(dmirror_devices + id);
> unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES);
> }
>
> diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
> index 625f3690d086..e190b2ab6f19 100644
> --- a/lib/test_hmm_uapi.h
> +++ b/lib/test_hmm_uapi.h
> @@ -33,11 +33,12 @@ struct hmm_dmirror_cmd {
> /* Expose the address space of the calling process through hmm device file */
> #define HMM_DMIRROR_READ _IOWR('H', 0x00, struct hmm_dmirror_cmd)
> #define HMM_DMIRROR_WRITE _IOWR('H', 0x01, struct hmm_dmirror_cmd)
> -#define HMM_DMIRROR_MIGRATE _IOWR('H', 0x02, struct hmm_dmirror_cmd)
> -#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x03, struct hmm_dmirror_cmd)
> -#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x04, struct hmm_dmirror_cmd)
> -#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)
> -#define HMM_DMIRROR_GET_MEM_DEV_TYPE _IOWR('H', 0x06, struct hmm_dmirror_cmd)
> +#define HMM_DMIRROR_MIGRATE_TO_DEV _IOWR('H', 0x02, struct hmm_dmirror_cmd)
> +#define HMM_DMIRROR_MIGRATE_TO_SYS _IOWR('H', 0x03, struct hmm_dmirror_cmd)
> +#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x04, struct hmm_dmirror_cmd)
> +#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd)
> +#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x06, struct hmm_dmirror_cmd)
> +#define HMM_DMIRROR_GET_MEM_DEV_TYPE _IOWR('H', 0x07, struct hmm_dmirror_cmd)
>
> /*
> * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
> @@ -52,6 +53,8 @@ struct hmm_dmirror_cmd {
> * device the ioctl() is made
> * HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some
> * other device
> + * HMM_DMIRROR_PROT_DEV_COHERENT: Migrate device coherent page on the device
> + * the ioctl() is made
> */
> enum {
> HMM_DMIRROR_PROT_ERROR = 0xFF,
> @@ -63,6 +66,8 @@ enum {
> HMM_DMIRROR_PROT_ZERO = 0x10,
> HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20,
> HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30,
> + HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL = 0x40,
> + HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE = 0x50,
> };
>
> enum {
>
On Thu, 27 Jan 2022 17:20:40 -0600 "Sierra Guiza, Alejandro (Alex)" <[email protected]> wrote:
> Andrew,
> We're somehow new on this procedure. Are you referring to rebase this
> patch series to
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> <5.17-rc1 tag>?
No, against current Linus mainline, please.
[Public]
> -----Original Message-----
> From: Sierra Guiza, Alejandro (Alex) <[email protected]>
> Sent: Thursday, January 27, 2022 6:21 PM
> To: Andrew Morton <[email protected]>
> Cc: Kuehling, Felix <[email protected]>; [email protected];
> [email protected]; [email protected]; linux-
> [email protected]; [email protected]; dri-
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; Deucher,
> Alexander <[email protected]>
> Subject: Re: [PATCH v4 00/10] Add MEMORY_DEVICE_COHERENT for
> coherent device memory mapping
>
> Andrew,
> We're somehow new on this procedure. Are you referring to rebase this
> patch series to git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-
> next.git
> <5.17-rc1 tag>?
>
> Regards,
> Alex Sierra
>
> Alex Deucher,
> Just a quick heads up. This patch series contains changes to the amdgpu
> driver which we're planning to merge through Andrew's tree, If that's ok with
> you.
No problem.
Thanks!
Alex
>
> Regards,
> Alex Sierra
>
> On 1/27/2022 4:32 PM, Andrew Morton wrote:
> > On Wed, 26 Jan 2022 21:09:39 -0600 Alex Sierra <[email protected]>
> wrote:
> >
> >> This patch series introduces MEMORY_DEVICE_COHERENT, a type of
> memory
> >> owned by a device that can be mapped into CPU page tables like
> >> MEMORY_DEVICE_GENERIC and can also be migrated like
> >> MEMORY_DEVICE_PRIVATE.
> > Some more reviewer input appears to be desirable here.
> >
> > I was going to tentatively add it to -mm and -next, but problems.
> > 5.17-rc1's mm/migrate.c:migrate_vma_check_page() is rather different
> > from the tree you patched. Please redo, refresh and resend?
> >
Thank you, Alex for your persistence with this patch series. Fee free to
add my Acked-by to all the patches that don't already have my R-b. I
have done pretty through reviews of previous versions of those patches,
but obviously missed a lot of issues pointed out by real MM experts.
Thank you Alistair for your reviews, feedback and collaboration!
Regards,
Felix
Am 2022-01-27 um 18:20 schrieb Sierra Guiza, Alejandro (Alex):
> Andrew,
> We're somehow new on this procedure. Are you referring to rebase this
> patch series to
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> <5.17-rc1 tag>?
>
> Regards,
> Alex Sierra
>
> Alex Deucher,
> Just a quick heads up. This patch series contains changes to the
> amdgpu driver which we're
> planning to merge through Andrew's tree, If that's ok with you.
>
> Regards,
> Alex Sierra
>
> On 1/27/2022 4:32 PM, Andrew Morton wrote:
>> On Wed, 26 Jan 2022 21:09:39 -0600 Alex Sierra <[email protected]>
>> wrote:
>>
>>> This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory
>>> owned by a device that can be mapped into CPU page tables like
>>> MEMORY_DEVICE_GENERIC and can also be migrated like
>>> MEMORY_DEVICE_PRIVATE.
>> Some more reviewer input appears to be desirable here.
>>
>> I was going to tentatively add it to -mm and -next, but problems.
>> 5.17-rc1's mm/migrate.c:migrate_vma_check_page() is rather different
>> from the tree you patched. Please redo, refresh and resend?
>>
On Thu, Jan 27, 2022 at 02:32:58PM -0800, Andrew Morton wrote:
> On Wed, 26 Jan 2022 21:09:39 -0600 Alex Sierra <[email protected]> wrote:
>
> > This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory
> > owned by a device that can be mapped into CPU page tables like
> > MEMORY_DEVICE_GENERIC and can also be migrated like
> > MEMORY_DEVICE_PRIVATE.
>
> Some more reviewer input appears to be desirable here.
>
> I was going to tentatively add it to -mm and -next, but problems.
> 5.17-rc1's mm/migrate.c:migrate_vma_check_page() is rather different
> from the tree you patched. Please redo, refresh and resend?
I really hate adding more types with the weird one off page refcount.
We need to clean that mess up first.
On Wed, Feb 02, 2022 at 03:57:50PM +0100, Christoph Hellwig wrote:
> On Thu, Jan 27, 2022 at 02:32:58PM -0800, Andrew Morton wrote:
> > On Wed, 26 Jan 2022 21:09:39 -0600 Alex Sierra <[email protected]> wrote:
> >
> > > This patch series introduces MEMORY_DEVICE_COHERENT, a type of memory
> > > owned by a device that can be mapped into CPU page tables like
> > > MEMORY_DEVICE_GENERIC and can also be migrated like
> > > MEMORY_DEVICE_PRIVATE.
> >
> > Some more reviewer input appears to be desirable here.
> >
> > I was going to tentatively add it to -mm and -next, but problems.
> > 5.17-rc1's mm/migrate.c:migrate_vma_check_page() is rather different
> > from the tree you patched. Please redo, refresh and resend?
>
> I really hate adding more types with the weird one off page refcount.
> We need to clean that mess up first.
Is there anyone who could give an outline of what is needed to make
fsdax use compound pages/folios for its PMD stuff?
I already suggested removing that as a way forward, and was shot down,
but nobody is standing up to maintain this code and fix it :(
We got devdax and the DRM stuff fixed now, so FSDAX is the next
blocker on this work.
The people who want this to advance have no idea about FSs or what to
do, unfortunately.
Jason