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[85.23.48.6]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-55b887f72f4sm5620240e87.0.2025.08.14.00.24.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Aug 2025 00:24:43 -0700 (PDT) From: =?UTF-8?q?Mika=20Penttil=C3=A4?= To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, =?UTF-8?q?Mika=20Penttil=C3=A4?= , David Hildenbrand , Jason Gunthorpe , Leon Romanovsky , Alistair Popple , Balbir Singh , Marco Pagani Subject: [RFC PATCH 4/4] mm: add new testcase for the migrate on fault case Date: Thu, 14 Aug 2025 10:19:29 +0300 Message-ID: <20250814072045.3637192-6-mpenttil@redhat.com> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250814072045.3637192-1-mpenttil@redhat.com> References: <20250814072045.3637192-1-mpenttil@redhat.com> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: Pi96MVwT5xJvE53RGTRUWLUCoCzRoI24xRV6dkwKmjI_1755156286 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 1CF721C0003 X-Rspamd-Server: rspam04 X-Rspam-User: X-Stat-Signature: 93tycm6xzdtqqq9ywa4fc3xcggyx7mex X-HE-Tag: 1755156288-978895 X-HE-Meta: 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 4kDH8MX1 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Cc: David Hildenbrand Cc: Jason Gunthorpe Cc: Leon Romanovsky Cc: Alistair Popple Cc: Balbir Singh Signed-off-by: Marco Pagani Signed-off-by: Mika Penttilä --- lib/test_hmm.c | 100 ++++++++++++++++++++++++- lib/test_hmm_uapi.h | 17 +++-- tools/testing/selftests/mm/hmm-tests.c | 53 +++++++++++++ 3 files changed, 161 insertions(+), 9 deletions(-) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index cd5c139213be..e69a5c87e414 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -36,6 +36,7 @@ #define DMIRROR_RANGE_FAULT_TIMEOUT 1000 #define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U) #define DEVMEM_CHUNKS_RESERVE 16 +#define PFNS_ARRAY_SIZE 64 /* * For device_private pages, dpage is just a dummy struct page @@ -143,7 +144,7 @@ static bool dmirror_is_private_zone(struct dmirror_device *mdevice) HMM_DMIRROR_MEMORY_DEVICE_PRIVATE) ? true : false; } -static enum migrate_vma_direction +static enum migrate_vma_info dmirror_select_device(struct dmirror *dmirror) { return (dmirror->mdevice->zone_device_type == @@ -1016,6 +1017,99 @@ static int dmirror_migrate_to_device(struct dmirror *dmirror, return ret; } +static int do_fault_and_migrate(struct dmirror *dmirror, struct hmm_range *range) +{ + struct migrate_vma *migrate = range->migrate; + int ret; + + mmap_read_lock(dmirror->notifier.mm); + + /* Fault-in pages for migration and update device page table */ + ret = dmirror_range_fault(dmirror, range); + + pr_debug("Migrating from sys mem to device mem\n"); + migrate_hmm_range_setup(range); + + dmirror_migrate_alloc_and_copy(migrate, dmirror); + migrate_vma_pages(migrate); + dmirror_migrate_finalize_and_map(migrate, dmirror); + migrate_vma_finalize(migrate); + + mmap_read_unlock(dmirror->notifier.mm); + return ret; +} + +static int dmirror_fault_and_migrate_to_device(struct dmirror *dmirror, + struct hmm_dmirror_cmd *cmd) +{ + unsigned long start, size, end, next; + unsigned long src_pfns[PFNS_ARRAY_SIZE] = { 0 }; + unsigned long dst_pfns[PFNS_ARRAY_SIZE] = { 0 }; + struct migrate_vma migrate = { 0 }; + struct hmm_range range = { 0 }; + struct dmirror_bounce bounce; + int ret = 0; + + /* Whole range */ + start = cmd->addr; + size = cmd->npages << PAGE_SHIFT; + end = start + size; + + if (!mmget_not_zero(dmirror->notifier.mm)) { + ret = -EFAULT; + goto out; + } + + migrate.pgmap_owner = dmirror->mdevice; + migrate.src = src_pfns; + migrate.dst = dst_pfns; + + range.migrate = &migrate; + range.hmm_pfns = src_pfns; + range.pfn_flags_mask = 0; + range.default_flags = HMM_PFN_REQ_FAULT | HMM_PFN_REQ_MIGRATE; + range.dev_private_owner = dmirror->mdevice; + range.notifier = &dmirror->notifier; + + for (next = start; next < end; next = range.end) { + range.start = next; + range.end = min(end, next + (PFNS_ARRAY_SIZE << PAGE_SHIFT)); + + pr_debug("Fault and migrate range start:%#lx end:%#lx\n", + range.start, range.end); + + ret = do_fault_and_migrate(dmirror, &range); + if (ret) + goto out_mmput; + } + + /* + * Return the migrated data for verification. + * Only for pages in device zone + ***/ + ret = dmirror_bounce_init(&bounce, start, size); + if (ret) + goto out_mmput; + + mutex_lock(&dmirror->mutex); + ret = dmirror_do_read(dmirror, start, end, &bounce); + mutex_unlock(&dmirror->mutex); + if (ret == 0) { + ret = copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr, bounce.size); + if (ret) + ret = -EFAULT; + } + + cmd->cpages = bounce.cpages; + dmirror_bounce_fini(&bounce); + + +out_mmput: + mmput(dmirror->notifier.mm); +out: + return ret; +} + static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range, unsigned char *perm, unsigned long entry) { @@ -1313,6 +1407,10 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp, ret = dmirror_migrate_to_device(dmirror, &cmd); break; + case HMM_DMIRROR_MIGRATE_ON_FAULT_TO_DEV: + ret = dmirror_fault_and_migrate_to_device(dmirror, &cmd); + break; + case HMM_DMIRROR_MIGRATE_TO_SYS: ret = dmirror_migrate_to_system(dmirror, &cmd); break; diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h index 8c818a2cf4f6..4266f0a12201 100644 --- a/lib/test_hmm_uapi.h +++ b/lib/test_hmm_uapi.h @@ -29,14 +29,15 @@ 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_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_RELEASE _IOWR('H', 0x07, struct hmm_dmirror_cmd) +#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_TO_DEV _IOWR('H', 0x02, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_MIGRATE_ON_FAULT_TO_DEV _IOWR('H', 0x03, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_MIGRATE_TO_SYS _IOWR('H', 0x04, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x05, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x06, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x07, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_RELEASE _IOWR('H', 0x08, struct hmm_dmirror_cmd) /* * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT. diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c index 141bf63cbe05..059512f62d29 100644 --- a/tools/testing/selftests/mm/hmm-tests.c +++ b/tools/testing/selftests/mm/hmm-tests.c @@ -272,6 +272,13 @@ static int hmm_migrate_sys_to_dev(int fd, return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_TO_DEV, buffer, npages); } +static int hmm_migrate_on_fault_sys_to_dev(int fd, + struct hmm_buffer *buffer, + unsigned long npages) +{ + return hmm_dmirror_cmd(fd, HMM_DMIRROR_MIGRATE_ON_FAULT_TO_DEV, buffer, npages); +} + static int hmm_migrate_dev_to_sys(int fd, struct hmm_buffer *buffer, unsigned long npages) @@ -998,6 +1005,52 @@ TEST_F(hmm, migrate) hmm_buffer_free(buffer); } +/* + * Fault an migrate anonymous memory to device private memory. + */ +TEST_F(hmm, migrate_on_fault) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + int *ptr; + int ret; + + npages = ALIGN(HMM_BUFFER_SIZE, self->page_size) >> self->page_shift; + ASSERT_NE(npages, 0); + 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; + + /* Fault and migrate memory to device. */ + ret = hmm_migrate_on_fault_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); + + hmm_buffer_free(buffer); +} + /* * 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 -- 2.50.0