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mm/hmm/test: use the new migration invalidation 

Use the new MMU_NOTIFY_MIGRATE event to skip MMU invalidations of device
private memory and handle the invalidation in the driver as part of
migrating device private memory.

Link: https://lore.kernel.org/r/20200723223004.9586-6-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
zero-sugar-mainline-defconfig
Ralph Campbell 2020-07-23 15:30:03 -07:00 committed by Jason Gunthorpe
parent f8477ce6b5
commit 7d17e83abe
2 changed files with 31 additions and 17 deletions
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30
lib/test_hmm.c
View File

@ -214,6 +214,14 @@ static bool dmirror_interval_invalidate(struct mmu_interval_notifier *mni,
{
struct dmirror *dmirror = container_of(mni, struct dmirror, notifier);
/*
* Ignore invalidation callbacks for device private pages since
* the invalidation is handled as part of the migration process.
*/
if (range->event == MMU_NOTIFY_MIGRATE &&
range->migrate_pgmap_owner == dmirror->mdevice)
return true;
if (mmu_notifier_range_blockable(range))
mutex_lock(&dmirror->mutex);
else if (!mutex_trylock(&dmirror->mutex))
@ -693,7 +701,7 @@ static int dmirror_migrate(struct dmirror *dmirror,
args.dst = dst_pfns;
args.start = addr;
args.end = next;
args.pgmap_owner = NULL;
args.pgmap_owner = dmirror->mdevice;
args.flags = MIGRATE_VMA_SELECT_SYSTEM;
ret = migrate_vma_setup(&args);
if (ret)
@ -983,7 +991,7 @@ static void dmirror_devmem_free(struct page *page)
}
static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args,
struct dmirror_device *mdevice)
struct dmirror *dmirror)
{
const unsigned long *src = args->src;
unsigned long *dst = args->dst;
@ -1005,6 +1013,7 @@ static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args,
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)
@ -1013,15 +1022,6 @@ static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args,
return 0;
}
static void dmirror_devmem_fault_finalize_and_map(struct migrate_vma *args,
struct dmirror *dmirror)
{
/* Invalidate the device's page table mapping. */
mutex_lock(&dmirror->mutex);
dmirror_do_update(dmirror, args->start, args->end);
mutex_unlock(&dmirror->mutex);
}
static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf)
{
struct migrate_vma args;
@ -1051,11 +1051,15 @@ static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf)
if (migrate_vma_setup(&args))
return VM_FAULT_SIGBUS;
ret = dmirror_devmem_fault_alloc_and_copy(&args, dmirror->mdevice);
ret = dmirror_devmem_fault_alloc_and_copy(&args, dmirror);
if (ret)
return ret;
migrate_vma_pages(&args);
dmirror_devmem_fault_finalize_and_map(&args, dmirror);
/*
* No device finalize step is needed since
* dmirror_devmem_fault_alloc_and_copy() will have already
* invalidated the device page table.
*/
migrate_vma_finalize(&args);
return 0;
}

18
tools/testing/selftests/vm/hmm-tests.c
View File

@ -881,8 +881,9 @@ TEST_F(hmm, migrate)
}
/*
* Migrate anonymous memory to device private memory and fault it back to system
* memory.
* Migrate anonymous memory to device private memory and fault some of it back
* to system memory, then try migrating the resulting mix of system and device
* private memory to the device.
*/
TEST_F(hmm, migrate_fault)
{
@ -924,8 +925,17 @@ TEST_F(hmm, migrate_fault)
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. */
for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
/* Fault half the pages back to system memory and check them. */
for (i = 0, ptr = buffer->ptr; i < size / (2 * sizeof(*ptr)); ++i)
ASSERT_EQ(ptr[i], i);
/* Migrate memory to the device again. */
ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_MIGRATE, 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);
hmm_buffer_free(buffer);