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.
Signed-off-by: Ralph Campbell rcampbell@nvidia.com --- lib/test_hmm.c | 30 +++++++++++++++----------- tools/testing/selftests/vm/hmm-tests.c | 18 ++++++++++++---- 2 files changed, 31 insertions(+), 17 deletions(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c index e78a1414f58e..e7dc3de355b7 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -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; } diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c index b533dd08da1d..91d38a29956b 100644 --- a/tools/testing/selftests/vm/hmm-tests.c +++ b/tools/testing/selftests/vm/hmm-tests.c @@ -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);