From e478425bec930e9368c6efdc78d2e5d85eadc18e Mon Sep 17 00:00:00 2001 From: Ralph Campbell Date: Wed, 1 Jul 2020 15:53:52 -0700 Subject: mm/hmm: add tests for hmm_pfn_to_map_order() Add a sanity test for hmm_range_fault() returning the page mapping size order. Link: https://lore.kernel.org/r/20200701225352.9649-6-rcampbell@nvidia.com Signed-off-by: Ralph Campbell Signed-off-by: Jason Gunthorpe --- lib/test_hmm.c | 4 ++++ lib/test_hmm_uapi.h | 4 ++++ 2 files changed, 8 insertions(+) (limited to 'lib') diff --git a/lib/test_hmm.c b/lib/test_hmm.c index a2a82262b97b..9aa577afc269 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -766,6 +766,10 @@ static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range, *perm |= HMM_DMIRROR_PROT_WRITE; else *perm |= HMM_DMIRROR_PROT_READ; + if (hmm_pfn_to_map_order(entry) + PAGE_SHIFT == PMD_SHIFT) + *perm |= HMM_DMIRROR_PROT_PMD; + else if (hmm_pfn_to_map_order(entry) + PAGE_SHIFT == PUD_SHIFT) + *perm |= HMM_DMIRROR_PROT_PUD; } static bool dmirror_snapshot_invalidate(struct mmu_interval_notifier *mni, diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h index 67b3b2e6ff5d..670b4ef2a5b6 100644 --- a/lib/test_hmm_uapi.h +++ b/lib/test_hmm_uapi.h @@ -40,6 +40,8 @@ struct hmm_dmirror_cmd { * HMM_DMIRROR_PROT_NONE: unpopulated PTE or PTE with no access * HMM_DMIRROR_PROT_READ: read-only PTE * HMM_DMIRROR_PROT_WRITE: read/write PTE + * HMM_DMIRROR_PROT_PMD: PMD sized page is fully mapped by same permissions + * HMM_DMIRROR_PROT_PUD: PUD sized page is fully mapped by same permissions * HMM_DMIRROR_PROT_ZERO: special read-only zero page * HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL: Migrated device private page on the * device the ioctl() is made @@ -51,6 +53,8 @@ enum { HMM_DMIRROR_PROT_NONE = 0x00, HMM_DMIRROR_PROT_READ = 0x01, HMM_DMIRROR_PROT_WRITE = 0x02, + HMM_DMIRROR_PROT_PMD = 0x04, + HMM_DMIRROR_PROT_PUD = 0x08, HMM_DMIRROR_PROT_ZERO = 0x10, HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20, HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30, -- cgit v1.2.3 From 5143192cd410c4fc83be09a2e73423765aee072b Mon Sep 17 00:00:00 2001 From: Ralph Campbell Date: Thu, 23 Jul 2020 15:30:00 -0700 Subject: mm/migrate: add a flags parameter to migrate_vma The src_owner field in struct migrate_vma is being used for two purposes, it acts as a selection filter for which types of pages are to be migrated and it identifies device private pages owned by the caller. Split this into separate parameters so the src_owner field can be used just to identify device private pages owned by the caller of migrate_vma_setup(). Rename the src_owner field to pgmap_owner to reflect it is now used only to identify which device private pages to migrate. Link: https://lore.kernel.org/r/20200723223004.9586-3-rcampbell@nvidia.com Signed-off-by: Ralph Campbell Reviewed-by: Bharata B Rao Signed-off-by: Jason Gunthorpe --- arch/powerpc/kvm/book3s_hv_uvmem.c | 4 +++- drivers/gpu/drm/nouveau/nouveau_dmem.c | 4 +++- include/linux/migrate.h | 13 +++++++++---- lib/test_hmm.c | 15 ++++----------- mm/migrate.c | 6 ++++-- 5 files changed, 23 insertions(+), 19 deletions(-) (limited to 'lib') diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index 09d8119024db..6850bd04bcb9 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -400,6 +400,7 @@ kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start, mig.end = end; mig.src = &src_pfn; mig.dst = &dst_pfn; + mig.flags = MIGRATE_VMA_SELECT_SYSTEM; /* * We come here with mmap_lock write lock held just for @@ -577,7 +578,8 @@ kvmppc_svm_page_out(struct vm_area_struct *vma, unsigned long start, mig.end = end; mig.src = &src_pfn; mig.dst = &dst_pfn; - mig.src_owner = &kvmppc_uvmem_pgmap; + mig.pgmap_owner = &kvmppc_uvmem_pgmap; + mig.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE; mutex_lock(&kvm->arch.uvmem_lock); /* The requested page is already paged-out, nothing to do */ diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c index e5c230d9ae24..78b9e3c2a5b3 100644 --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c @@ -182,7 +182,8 @@ static vm_fault_t nouveau_dmem_migrate_to_ram(struct vm_fault *vmf) .end = vmf->address + PAGE_SIZE, .src = &src, .dst = &dst, - .src_owner = drm->dev, + .pgmap_owner = drm->dev, + .flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE, }; /* @@ -615,6 +616,7 @@ nouveau_dmem_migrate_vma(struct nouveau_drm *drm, struct migrate_vma args = { .vma = vma, .start = start, + .flags = MIGRATE_VMA_SELECT_SYSTEM, }; unsigned long i; u64 *pfns; diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 3e546cbf03dd..16e03a51e5cf 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -180,6 +180,11 @@ static inline unsigned long migrate_pfn(unsigned long pfn) return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID; } +enum migrate_vma_direction { + MIGRATE_VMA_SELECT_SYSTEM = 1 << 0, + MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1, +}; + struct migrate_vma { struct vm_area_struct *vma; /* @@ -199,11 +204,11 @@ struct migrate_vma { /* * Set to the owner value also stored in page->pgmap->owner for - * migrating out of device private memory. If set only device - * private pages with this owner are migrated. If not set - * device private pages are not migrated at all. + * migrating out of device private memory. The flags also need to + * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE. */ - void *src_owner; + void *pgmap_owner; + unsigned long flags; }; int migrate_vma_setup(struct migrate_vma *args); diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 9aa577afc269..e78a1414f58e 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -585,15 +585,6 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args, */ spage = migrate_pfn_to_page(*src); - /* - * Don't migrate device private pages from our own driver or - * others. For our own we would do a device private memory copy - * not a migration and for others, we would need to fault the - * other device's page into system memory first. - */ - if (spage && is_zone_device_page(spage)) - continue; - dpage = dmirror_devmem_alloc_page(mdevice); if (!dpage) continue; @@ -702,7 +693,8 @@ static int dmirror_migrate(struct dmirror *dmirror, args.dst = dst_pfns; args.start = addr; args.end = next; - args.src_owner = NULL; + args.pgmap_owner = NULL; + args.flags = MIGRATE_VMA_SELECT_SYSTEM; ret = migrate_vma_setup(&args); if (ret) goto out; @@ -1053,7 +1045,8 @@ static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf) args.end = args.start + PAGE_SIZE; args.src = &src_pfns; args.dst = &dst_pfns; - args.src_owner = dmirror->mdevice; + args.pgmap_owner = dmirror->mdevice; + args.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE; if (migrate_vma_setup(&args)) return VM_FAULT_SIGBUS; diff --git a/mm/migrate.c b/mm/migrate.c index f37729673558..e3ea68e3a08b 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2287,7 +2287,9 @@ again: goto next; page = device_private_entry_to_page(entry); - if (page->pgmap->owner != migrate->src_owner) + if (!(migrate->flags & + MIGRATE_VMA_SELECT_DEVICE_PRIVATE) || + page->pgmap->owner != migrate->pgmap_owner) goto next; mpfn = migrate_pfn(page_to_pfn(page)) | @@ -2295,7 +2297,7 @@ again: if (is_write_device_private_entry(entry)) mpfn |= MIGRATE_PFN_WRITE; } else { - if (migrate->src_owner) + if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM)) goto next; pfn = pte_pfn(pte); if (is_zero_pfn(pfn)) { -- cgit v1.2.3 From 7d17e83abec1be3355260b3e4812044c65c32907 Mon Sep 17 00:00:00 2001 From: Ralph Campbell Date: Thu, 23 Jul 2020 15:30:03 -0700 Subject: 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 Signed-off-by: Jason Gunthorpe --- lib/test_hmm.c | 30 +++++++++++++++++------------- tools/testing/selftests/vm/hmm-tests.c | 18 ++++++++++++++---- 2 files changed, 31 insertions(+), 17 deletions(-) (limited to 'lib') 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); -- cgit v1.2.3