This is our MEMORY_DEVICE_COHERENT patch series rebased and updated
for current 5.19.0-rc5
Changes since the last version:
- Fixed problems with migration during long-term pinning in
get_user_pages
- Open coded vm_normal_lru_pages as suggested in previous code review
- Update hmm_gup_test with more get_user_pages calls, include
hmm_cow_in_device in hmm-test.
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.
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.
Coherent device type pages at gup are now migrated back to system
memory if they are being pinned long-term (FOLL_LONGTERM). The reason
is, that long-term pinning would interfere with the device memory
manager owning the device-coherent pages (e.g. evictions in TTM).
These series incorporate Alistair Popple patches to do this
migration from pin_user_pages() calls. hmm_gup_test has been added to
hmm-test to test different get user pages calls.
This series includes handling of device-managed anonymous pages
returned by vm_normal_pages. Although they behave like normal pages
for purposes of mapping in CPU page tables and for COW, they do not
support LRU lists, NUMA migration or THP.
We also introduced a FOLL_LRU flag that adds the same behaviour to
follow_page and related APIs, to allow callers to specify that they
expect to put pages on an LRU list.
v2:
- Rebase to latest 5.18-rc7.
- Drop patch "mm: add device coherent checker to remove migration pte"
and modify try_to_migrate_one, to let DEVICE_COHERENT pages fall
through to normal page path. Based on Alistair Popple's comment.
- Fix comment formatting.
- Reword comment in vm_normal_page about pte_devmap().
- Merge "drm/amdkfd: coherent type as sys mem on migration to ram" to
"drm/amdkfd: add SPM support for SVM".
v3:
- Rebase to latest 5.18.0.
- Patch "mm: handling Non-LRU pages returned by vm_normal_pages"
reordered.
- Add WARN_ON_ONCE for thp device coherent case.
v4:
- Rebase to latest 5.18.0
- Fix consitency between pages with FOLL_LRU flag set and pte_devmap
at follow_page_pte.
v5:
- Remove unused zone_device_type from lib/test_hmm and
selftest/vm/hmm-test.c.
v6:
- Rebase to 5.19.0-rc4
- Rename is_pinnable_page to is_longterm_pinnable_page and add a
coherent device checker.
- Add a new gup test to hmm-test to cover fast pinnable case with
FOLL_LONGTERM.
v7:
- Reorder patch series.
- Remove FOLL_LRU and check on each caller for LRU pages handling
instead.
v8:
- Add "mm: move page zone helpers into new header-specific file"
patch. The intention is to centralize all page zone helpers and keep
them independent from mm.h and memremap.h.
Alex Sierra (13):
mm: rename is_pinnable_pages to is_longterm_pinnable_pages
mm: move page zone helpers into new header-specific file
mm: add zone device coherent type memory support
mm: handling Non-LRU pages returned by vm_normal_pages
mm: add device coherent vma selection for memory migration
drm/amdkfd: add SPM support for SVM
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
tools: add hmm gup tests for device coherent type
tools: add selftests to hmm for COW in device memory
Alistair Popple (2):
mm: remove the vma check in migrate_vma_setup()
mm/gup: migrate device coherent pages when pinning instead of failing
drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 34 ++-
drivers/infiniband/core/rw.c | 1 -
drivers/nvme/target/io-cmd-bdev.c | 1 -
fs/proc/task_mmu.c | 2 +-
include/linux/memremap.h | 113 +-------
include/linux/migrate.h | 1 +
include/linux/mm.h | 91 +-----
include/linux/page_zone.h | 213 ++++++++++++++
lib/test_hmm.c | 337 +++++++++++++++++------
lib/test_hmm_uapi.h | 19 +-
mm/gup.c | 49 +++-
mm/gup_test.c | 2 +-
mm/huge_memory.c | 2 +-
mm/hugetlb.c | 2 +-
mm/internal.h | 1 +
mm/khugepaged.c | 9 +-
mm/ksm.c | 6 +-
mm/madvise.c | 4 +-
mm/memcontrol.c | 8 +-
mm/memory-failure.c | 8 +-
mm/memory.c | 10 +-
mm/mempolicy.c | 2 +-
mm/memremap.c | 10 +
mm/migrate.c | 4 +-
mm/migrate_device.c | 115 ++++++--
mm/mlock.c | 2 +-
mm/mprotect.c | 2 +-
mm/rmap.c | 5 +-
tools/testing/selftests/vm/hmm-tests.c | 311 +++++++++++++++++++--
tools/testing/selftests/vm/test_hmm.sh | 24 +-
30 files changed, 1005 insertions(+), 383 deletions(-)
create mode 100644 include/linux/page_zone.h
--
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]>
Acked-by: Felix Kuehling <[email protected]>
Reviewed-by: Alistair Poppple <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
---
lib/test_hmm.c | 11 +++++++++--
lib/test_hmm_uapi.h | 14 ++++++++++----
2 files changed, 19 insertions(+), 6 deletions(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index cfe632047839..915ef6b5b0d4 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -87,6 +87,7 @@ 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;
@@ -1260,14 +1261,20 @@ 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..0511af7464ee 100644
--- a/lib/test_hmm_uapi.h
+++ b/lib/test_hmm_uapi.h
@@ -31,10 +31,11 @@ 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_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)
/*
* Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
@@ -62,4 +63,9 @@ 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
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.
Also, MIGRATE_VMA_SELECT_DEVICE_COHERENT flag is selected for
coherent type case during migration to device.
Signed-off-by: Alex Sierra <[email protected]>
Reviewed-by: Felix Kuehling <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
---
drivers/gpu/drm/amd/amdkfd/kfd_migrate.c | 34 +++++++++++++++---------
1 file changed, 21 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index e44376c2ecdc..f73e3e340413 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -671,13 +671,15 @@ 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;
buf = kvcalloc(npages,
2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t),
GFP_KERNEL);
-
if (!buf)
goto out;
@@ -947,7 +949,7 @@ 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;
@@ -962,28 +964,34 @@ 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);
}
--
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]>
Acked-by: Felix Kuehling <[email protected]>
Reviewed-by: Alistair Poppple <[email protected]>
Signed-off-by: Christoph Hellwig <[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 915ef6b5b0d4..afb30af9f3ff 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -37,6 +37,16 @@
#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;
@@ -455,28 +465,44 @@ 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;
@@ -497,10 +523,14 @@ 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;
@@ -529,15 +559,17 @@ 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)
@@ -562,7 +594,7 @@ 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;
}
@@ -1232,10 +1264,8 @@ 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)
@@ -1248,8 +1278,9 @@ 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 0511af7464ee..f700da7807c1 100644
--- a/lib/test_hmm_uapi.h
+++ b/lib/test_hmm_uapi.h
@@ -66,6 +66,7 @@ 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
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]>
Acked-by: Felix Kuehling <[email protected]>
Reviewed-by: Alistair Popple <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
---
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
From: Alistair Popple <[email protected]>
migrate_vma_setup() checks that a valid vma is passed so that the page
tables can be walked to find the pfns associated with a given address
range. However in some cases the pfns are already known, such as when
migrating device coherent pages during pin_user_pages() meaning a valid
vma isn't required.
Signed-off-by: Alistair Popple <[email protected]>
Acked-by: Felix Kuehling <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
---
mm/migrate_device.c | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index 18bc6483f63a..cf9668376c5a 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -486,24 +486,24 @@ int migrate_vma_setup(struct migrate_vma *args)
args->start &= PAGE_MASK;
args->end &= PAGE_MASK;
- if (!args->vma || is_vm_hugetlb_page(args->vma) ||
- (args->vma->vm_flags & VM_SPECIAL) || vma_is_dax(args->vma))
- return -EINVAL;
- if (nr_pages <= 0)
- return -EINVAL;
- if (args->start < args->vma->vm_start ||
- args->start >= args->vma->vm_end)
- return -EINVAL;
- if (args->end <= args->vma->vm_start || args->end > args->vma->vm_end)
- return -EINVAL;
if (!args->src || !args->dst)
return -EINVAL;
-
- memset(args->src, 0, sizeof(*args->src) * nr_pages);
- args->cpages = 0;
- args->npages = 0;
-
- migrate_vma_collect(args);
+ if (args->vma) {
+ if (is_vm_hugetlb_page(args->vma) ||
+ (args->vma->vm_flags & VM_SPECIAL) || vma_is_dax(args->vma))
+ return -EINVAL;
+ if (args->start < args->vma->vm_start ||
+ args->start >= args->vma->vm_end)
+ return -EINVAL;
+ if (args->end <= args->vma->vm_start ||
+ args->end > args->vma->vm_end)
+ return -EINVAL;
+ memset(args->src, 0, sizeof(*args->src) * nr_pages);
+ args->cpages = 0;
+ args->npages = 0;
+
+ migrate_vma_collect(args);
+ }
if (args->cpages)
migrate_vma_unmap(args);
@@ -685,7 +685,7 @@ void migrate_vma_pages(struct migrate_vma *migrate)
continue;
}
- if (!page) {
+ if (!page && migrate->vma) {
if (!(migrate->src[i] & MIGRATE_PFN_MIGRATE))
continue;
if (!notified) {
--
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]>
Acked-by: Felix Kuehling <[email protected]>
Reviewed-by: Alistair Popple <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
---
tools/testing/selftests/vm/hmm-tests.c | 121 ++++++++++++++++++++-----
1 file changed, 100 insertions(+), 21 deletions(-)
diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index 203323967b50..4b547188ec40 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -46,6 +46,13 @@ struct hmm_buffer {
uint64_t faults;
};
+enum {
+ HMM_PRIVATE_DEVICE_ONE,
+ HMM_PRIVATE_DEVICE_TWO,
+ HMM_COHERENCE_DEVICE_ONE,
+ HMM_COHERENCE_DEVICE_TWO,
+};
+
#define TWOMEG (1 << 21)
#define HMM_BUFFER_SIZE (1024 << 12)
#define HMM_PATH_MAX 64
@@ -60,6 +67,21 @@ 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 +90,24 @@ 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 +121,19 @@ 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 +142,11 @@ 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);
}
@@ -211,6 +260,20 @@ 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 +938,7 @@ 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 +986,7 @@ 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 +999,7 @@ 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 +1039,7 @@ 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 +1078,7 @@ 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 +1086,7 @@ 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 +1118,13 @@ 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 +1133,12 @@ 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 +1174,7 @@ 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 +1182,13 @@ 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);
@@ -1354,13 +1426,13 @@ 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);
@@ -1377,9 +1449,16 @@ 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
The intention is to test hmm device coherent type under different get
user pages paths. Also, test gup with FOLL_LONGTERM flag set in
device coherent pages. These pages should get migrated back to system
memory.
Signed-off-by: Alex Sierra <[email protected]>
Reviewed-by: Alistair Popple <[email protected]>
---
tools/testing/selftests/vm/hmm-tests.c | 110 +++++++++++++++++++++++++
1 file changed, 110 insertions(+)
diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index 4b547188ec40..bb38b9777610 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -36,6 +36,7 @@
* in the usual include/uapi/... directory.
*/
#include "../../../../lib/test_hmm_uapi.h"
+#include "../../../../mm/gup_test.h"
struct hmm_buffer {
void *ptr;
@@ -59,6 +60,9 @@ enum {
#define NTIMES 10
#define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1)))
+/* Just the flags we need, copied from mm.h: */
+#define FOLL_WRITE 0x01 /* check pte is writable */
+#define FOLL_LONGTERM 0x10000 /* mapping lifetime is indefinite */
FIXTURE(hmm)
{
@@ -1764,4 +1768,110 @@ TEST_F(hmm, exclusive_cow)
hmm_buffer_free(buffer);
}
+static int gup_test_exec(int gup_fd, unsigned long addr, int cmd,
+ int npages, int size, int flags)
+{
+ struct gup_test gup = {
+ .nr_pages_per_call = npages,
+ .addr = addr,
+ .gup_flags = FOLL_WRITE | flags,
+ .size = size,
+ };
+
+ if (ioctl(gup_fd, cmd, &gup)) {
+ perror("ioctl on error\n");
+ return errno;
+ }
+
+ return 0;
+}
+
+/*
+ * Test get user device pages through gup_test. Setting PIN_LONGTERM flag.
+ * This should trigger a migration back to system memory for both, private
+ * and coherent type pages.
+ * This test makes use of gup_test module. Make sure GUP_TEST_CONFIG is added
+ * to your configuration before you run it.
+ */
+TEST_F(hmm, hmm_gup_test)
+{
+ struct hmm_buffer *buffer;
+ int gup_fd;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ int *ptr;
+ int ret;
+ unsigned char *m;
+
+ gup_fd = open("/sys/kernel/debug/gup_test", O_RDWR);
+ if (gup_fd == -1)
+ SKIP(return, "Skipping test, could not find gup_test driver");
+
+ npages = 4;
+ size = npages << self->page_shift;
+
+ buffer = malloc(sizeof(*buffer));
+ ASSERT_NE(buffer, NULL);
+
+ buffer->fd = -1;
+ buffer->size = size;
+ buffer->mirror = malloc(size);
+ ASSERT_NE(buffer->mirror, NULL);
+
+ buffer->ptr = mmap(NULL, size,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS,
+ buffer->fd, 0);
+ ASSERT_NE(buffer->ptr, MAP_FAILED);
+
+ /* Initialize buffer in system memory. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Migrate memory to device. */
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+ /* Check what the device read. */
+ for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], i);
+
+ ASSERT_EQ(gup_test_exec(gup_fd,
+ (unsigned long)buffer->ptr,
+ GUP_BASIC_TEST, 1, self->page_size, 0), 0);
+ ASSERT_EQ(gup_test_exec(gup_fd,
+ (unsigned long)buffer->ptr + 1 * self->page_size,
+ GUP_FAST_BENCHMARK, 1, self->page_size, 0), 0);
+ ASSERT_EQ(gup_test_exec(gup_fd,
+ (unsigned long)buffer->ptr + 2 * self->page_size,
+ PIN_FAST_BENCHMARK, 1, self->page_size, FOLL_LONGTERM), 0);
+ ASSERT_EQ(gup_test_exec(gup_fd,
+ (unsigned long)buffer->ptr + 3 * self->page_size,
+ PIN_LONGTERM_BENCHMARK, 1, self->page_size, 0), 0);
+
+ /* Take snapshot to CPU pagetables */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+ m = buffer->mirror;
+ if (hmm_is_coherent_type(variant->device_number)) {
+ ASSERT_EQ(HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL | HMM_DMIRROR_PROT_WRITE, m[0]);
+ ASSERT_EQ(HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL | HMM_DMIRROR_PROT_WRITE, m[1]);
+ } else {
+ ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[0]);
+ ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[1]);
+ }
+ ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[2]);
+ ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[3]);
+ /*
+ * Check again the content on the pages. Make sure there's no
+ * corrupted data.
+ */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], i);
+
+ close(gup_fd);
+ hmm_buffer_free(buffer);
+}
TEST_HARNESS_MAIN
--
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]>
Acked-by: Felix Kuehling <[email protected]>
Reviewed-by: Alistair Poppple <[email protected]>
---
lib/test_hmm.c | 253 +++++++++++++++++++++++++++++++++-----------
lib/test_hmm_uapi.h | 4 +
2 files changed, 196 insertions(+), 61 deletions(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index afb30af9f3ff..7930853e7fc5 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -32,11 +32,22 @@
#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,
@@ -125,6 +136,21 @@ 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);
@@ -575,16 +601,19 @@ 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 allocate
+ * 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) {
@@ -603,7 +632,8 @@ static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
return dpage;
error:
- __free_page(rpage);
+ if (rpage)
+ __free_page(rpage);
return NULL;
}
@@ -629,12 +659,16 @@ 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
@@ -648,6 +682,8 @@ 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));
if ((*src & MIGRATE_PFN_WRITE) ||
(!spage && args->vma->vm_flags & VM_WRITE))
@@ -725,11 +761,7 @@ 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);
@@ -809,15 +841,126 @@ 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_device_private_page(spage) &&
+ !is_device_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));
+ 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];
- unsigned long dst_pfns[64];
+ 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] = { 0 };
+ unsigned long dst_pfns[64] = { 0 };
struct dmirror_bounce bounce;
struct migrate_vma args;
unsigned long next;
@@ -854,6 +997,7 @@ 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);
@@ -862,7 +1006,10 @@ 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;
@@ -905,6 +1052,12 @@ static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range,
*perm = HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL;
else
*perm = HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE;
+ } else if (is_device_coherent_page(page)) {
+ /* Is the page migrated to this device or some other? */
+ if (dmirror->mdevice == dmirror_page_to_device(page))
+ *perm = HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL;
+ else
+ *perm = HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE;
} else if (is_zero_pfn(page_to_pfn(page)))
*perm = HMM_DMIRROR_PROT_ZERO;
else
@@ -1092,8 +1245,12 @@ 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:
@@ -1155,14 +1312,13 @@ 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;
@@ -1170,43 +1326,11 @@ 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));
- 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;
@@ -1226,7 +1350,7 @@ 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;
@@ -1305,6 +1429,12 @@ 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)
@@ -1327,7 +1457,8 @@ 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 f700da7807c1..e31d58c9034a 100644
--- a/lib/test_hmm_uapi.h
+++ b/lib/test_hmm_uapi.h
@@ -50,6 +50,8 @@ 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,
@@ -61,6 +63,8 @@ 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
The objective is to test device migration mechanism in pages marked
as COW, for private and coherent device type. In case of writing to
COW private page(s), a page fault will migrate pages back to system
memory first. Then, these pages will be duplicated. In case of COW
device coherent type, pages are duplicated directly from device
memory.
Signed-off-by: Alex Sierra <[email protected]>
Acked-by: Felix Kuehling <[email protected]>
---
tools/testing/selftests/vm/hmm-tests.c | 80 ++++++++++++++++++++++++++
1 file changed, 80 insertions(+)
diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index bb38b9777610..716b62c05e3d 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -1874,4 +1874,84 @@ TEST_F(hmm, hmm_gup_test)
close(gup_fd);
hmm_buffer_free(buffer);
}
+
+/*
+ * Test copy-on-write in device pages.
+ * In case of writing to COW private page(s), a page fault will migrate pages
+ * back to system memory first. Then, these pages will be duplicated. In case
+ * of COW device coherent type, pages are duplicated directly from device
+ * memory.
+ */
+TEST_F(hmm, hmm_cow_in_device)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ int *ptr;
+ int ret;
+ unsigned char *m;
+ pid_t pid;
+ int status;
+
+ npages = 4;
+ size = npages << self->page_shift;
+
+ buffer = malloc(sizeof(*buffer));
+ ASSERT_NE(buffer, NULL);
+
+ buffer->fd = -1;
+ buffer->size = size;
+ buffer->mirror = malloc(size);
+ ASSERT_NE(buffer->mirror, NULL);
+
+ buffer->ptr = mmap(NULL, size,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS,
+ buffer->fd, 0);
+ ASSERT_NE(buffer->ptr, MAP_FAILED);
+
+ /* Initialize buffer in system memory. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Migrate memory to device. */
+
+ ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ pid = fork();
+ if (pid == -1)
+ ASSERT_EQ(pid, 0);
+ if (!pid) {
+ /* Child process waitd for SIGTERM from the parent. */
+ while (1) {
+ }
+ perror("Should not reach this\n");
+ exit(0);
+ }
+ /* Parent process writes to COW pages(s) and gets a
+ * new copy in system. In case of device private pages,
+ * this write causes a migration to system mem first.
+ */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Terminate child and wait */
+ EXPECT_EQ(0, kill(pid, SIGTERM));
+ EXPECT_EQ(pid, waitpid(pid, &status, 0));
+ EXPECT_NE(0, WIFSIGNALED(status));
+ EXPECT_EQ(SIGTERM, WTERMSIG(status));
+
+ /* Take snapshot to CPU pagetables */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+ m = buffer->mirror;
+ for (i = 0; i < npages; i++)
+ ASSERT_EQ(HMM_DMIRROR_PROT_WRITE, m[i]);
+
+ hmm_buffer_free(buffer);
+}
TEST_HARNESS_MAIN
--
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]>
Acked-by: Felix Kuehling <[email protected]>
Reviewed-by: Alistair Poppple <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
---
include/linux/migrate.h | 1 +
mm/migrate_device.c | 12 +++++++++---
2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 069a89e847f3..b84908debe5c 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -148,6 +148,7 @@ 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_device.c b/mm/migrate_device.c
index a4847ad65da3..18bc6483f63a 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -148,15 +148,21 @@ 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)) {
+ if (is_zero_pfn(pfn) &&
+ (migrate->flags & MIGRATE_VMA_SELECT_SYSTEM)) {
mpfn = MIGRATE_PFN_MIGRATE;
migrate->cpages++;
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;
+ else 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
On 07.07.22 21:03, Alex Sierra wrote:
> From: Alistair Popple <[email protected]>
>
> migrate_vma_setup() checks that a valid vma is passed so that the page
> tables can be walked to find the pfns associated with a given address
> range. However in some cases the pfns are already known, such as when
> migrating device coherent pages during pin_user_pages() meaning a valid
> vma isn't required.
As raised in my other reply, without a VMA ... it feels odd to use a
"migrate_vma" API. For an internal (mm/migrate_device.c) use case it is
ok I guess, but it certainly adds a bit of confusion. For example,
because migrate_vma_setup() will undo ref+lock not obtained by it.
I guess the interesting point is that
a) Besides migrate_vma_pages() and migrate_vma_setup(), the ->vma is unused.
b) migrate_vma_setup() does collect+unmap+cleanup if unmap failed.
c) With our source page in our hands, we cannot be processing a hole in
a VMA.
Not sure if it's better. but I would
a) Enforce in migrate_vma_setup() that there is a VMA. Code outside of
mm/migrate_device.c shouldn't be doing some hacks like this.
b) Don't call migrate_vma_setup() from migrate_device_page(), but
directly migrate_vma_unmap() and add a comment.
That will leave a single change to this patch (migrate_vma_pages()). But
is that even required? Because ....
> @@ -685,7 +685,7 @@ void migrate_vma_pages(struct migrate_vma *migrate)
> continue;
> }
>
> - if (!page) {
> + if (!page && migrate->vma) {
How could we ever have !page in case of migrate_device_page()?
Instead, I think a VM_BUG_ON(migrate->vma); should hold and you can just
simplify.
> if (!(migrate->src[i] & MIGRATE_PFN_MIGRATE))
> continue;
> if (!notified) {
--
Thanks,
David / dhildenb
David Hildenbrand <[email protected]> writes:
> On 07.07.22 21:03, Alex Sierra wrote:
>> From: Alistair Popple <[email protected]>
>>
>> migrate_vma_setup() checks that a valid vma is passed so that the page
>> tables can be walked to find the pfns associated with a given address
>> range. However in some cases the pfns are already known, such as when
>> migrating device coherent pages during pin_user_pages() meaning a valid
>> vma isn't required.
>
> As raised in my other reply, without a VMA ... it feels odd to use a
> "migrate_vma" API. For an internal (mm/migrate_device.c) use case it is
> ok I guess, but it certainly adds a bit of confusion. For example,
> because migrate_vma_setup() will undo ref+lock not obtained by it.
>
> I guess the interesting point is that
>
> a) Besides migrate_vma_pages() and migrate_vma_setup(), the ->vma is unused.
>
> b) migrate_vma_setup() does collect+unmap+cleanup if unmap failed.
>
> c) With our source page in our hands, we cannot be processing a hole in
> a VMA.
>
>
>
> Not sure if it's better. but I would
>
> a) Enforce in migrate_vma_setup() that there is a VMA. Code outside of
> mm/migrate_device.c shouldn't be doing some hacks like this.
>
> b) Don't call migrate_vma_setup() from migrate_device_page(), but
> directly migrate_vma_unmap() and add a comment.
>
>
> That will leave a single change to this patch (migrate_vma_pages()). But
> is that even required? Because ....
>
>> @@ -685,7 +685,7 @@ void migrate_vma_pages(struct migrate_vma *migrate)
>> continue;
>> }
>>
>> - if (!page) {
>> + if (!page && migrate->vma) {
>
> How could we ever have !page in case of migrate_device_page()?
Oh good point. This patch was originally part of a larger series I was
working on at the time but you're right - for migrate_device_page() we
should never hit this case. I will respin the next patch (number 7 in
this series) to include this.
> Instead, I think a VM_BUG_ON(migrate->vma); should hold and you can just
> simplify.
>
>> if (!(migrate->src[i] & MIGRATE_PFN_MIGRATE))
>> continue;
>> if (!notified) {