This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Changes v7 -> v8: Rebased to Jason's rdma/hmm tree, plus Jason's 6 patch series "Small hmm_range_fault() cleanups". Applied a number of changes from Jason's comments.
Changes v6 -> v7: Rebased to linux-5.6.0-rc6 Reverted back to just using mmu_interval_notifier_insert() and making this series only introduce HMM self tests.
Changes v5 -> v6: Rebased to linux-5.5.0-rc6 Refactored mmu interval notifier patches Converted nouveau to use the new mmu interval notifier API
Changes v4 -> v5: Added mmu interval notifier insert/remove/update callable from the invalidate() callback Updated HMM tests to use the new core interval notifier API
Changes v1 -> v4: https://lore.kernel.org/linux-mm/20191104222141.5173-1-rcampbell@nvidia.com
Ralph Campbell (3): mm/hmm/test: add selftest driver for HMM mm/hmm/test: add selftests for HMM MAINTAINERS: add HMM selftests
MAINTAINERS | 3 + include/uapi/linux/test_hmm.h | 59 ++ lib/Kconfig.debug | 12 + lib/Makefile | 1 + lib/test_hmm.c | 1177 +++++++++++++++++++++ tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 3 + tools/testing/selftests/vm/config | 2 + tools/testing/selftests/vm/hmm-tests.c | 1353 ++++++++++++++++++++++++ tools/testing/selftests/vm/run_vmtests | 16 + tools/testing/selftests/vm/test_hmm.sh | 97 ++ 11 files changed, 2724 insertions(+) create mode 100644 include/uapi/linux/test_hmm.h create mode 100644 lib/test_hmm.c create mode 100644 tools/testing/selftests/vm/hmm-tests.c create mode 100755 tools/testing/selftests/vm/test_hmm.sh
This driver is for testing device private memory migration and devices which use hmm_range_fault() to access system memory via device page tables.
Signed-off-by: Ralph Campbell rcampbell@nvidia.com Signed-off-by: Jérôme Glisse jglisse@redhat.com --- include/uapi/linux/test_hmm.h | 59 ++ lib/Kconfig.debug | 12 + lib/Makefile | 1 + lib/test_hmm.c | 1177 +++++++++++++++++++++++++++++++++ 4 files changed, 1249 insertions(+) create mode 100644 include/uapi/linux/test_hmm.h create mode 100644 lib/test_hmm.c
diff --git a/include/uapi/linux/test_hmm.h b/include/uapi/linux/test_hmm.h new file mode 100644 index 000000000000..8c5f70c160bf --- /dev/null +++ b/include/uapi/linux/test_hmm.h @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * This is a module to test the HMM (Heterogeneous Memory Management) API + * of the kernel. It allows a userspace program to expose its entire address + * space through the HMM test module device file. + */ +#ifndef _UAPI_LINUX_HMM_DMIRROR_H +#define _UAPI_LINUX_HMM_DMIRROR_H + +#include <linux/types.h> +#include <linux/ioctl.h> + +/* + * Structure to pass to the HMM test driver to mimic a device accessing + * system memory and ZONE_DEVICE private memory through device page tables. + * + * @addr: (in) user address the device will read/write + * @ptr: (in) user address where device data is copied to/from + * @npages: (in) number of pages to read/write + * @cpages: (out) number of pages copied + * @faults: (out) number of device page faults seen + */ +struct hmm_dmirror_cmd { + __u64 addr; + __u64 ptr; + __u64 npages; + __u64 cpages; + __u64 faults; +}; + +/* 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) + +/* + * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT. + * HMM_DMIRROR_PROT_ERROR: no valid mirror PTE for this page + * 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_ZERO: special read-only zero page + * HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL: Migrated device private page on the + * device the ioctl() is made + * HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some + * other device + */ +enum { + HMM_DMIRROR_PROT_ERROR = 0xFF, + HMM_DMIRROR_PROT_NONE = 0x00, + HMM_DMIRROR_PROT_READ = 0x01, + HMM_DMIRROR_PROT_WRITE = 0x02, + HMM_DMIRROR_PROT_ZERO = 0x10, + HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20, + HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30, +}; + +#endif /* _UAPI_LINUX_HMM_DMIRROR_H */ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 69def4a9df00..f777e1215e33 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2162,6 +2162,18 @@ config TEST_MEMINIT
If unsure, say N.
+config TEST_HMM + tristate "Test HMM (Heterogeneous Memory Management)" + depends on DEVICE_PRIVATE + select HMM_MIRROR + select MMU_NOTIFIER + help + This is a pseudo device driver solely for testing HMM. + Say M here if you want to build the HMM test module. + Doing so will allow you to run tools/testing/selftest/vm/hmm-tests. + + If unsure, say N. + endif # RUNTIME_TESTING_MENU
config MEMTEST diff --git a/lib/Makefile b/lib/Makefile index 611872c06926..c168bdc803dc 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -89,6 +89,7 @@ obj-$(CONFIG_TEST_OBJAGG) += test_objagg.o obj-$(CONFIG_TEST_STACKINIT) += test_stackinit.o obj-$(CONFIG_TEST_BLACKHOLE_DEV) += test_blackhole_dev.o obj-$(CONFIG_TEST_MEMINIT) += test_meminit.o +obj-$(CONFIG_TEST_HMM) += test_hmm.o
obj-$(CONFIG_TEST_LIVEPATCH) += livepatch/
diff --git a/lib/test_hmm.c b/lib/test_hmm.c new file mode 100644 index 000000000000..d75e18f2ffd2 --- /dev/null +++ b/lib/test_hmm.c @@ -0,0 +1,1177 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This is a module to test the HMM (Heterogeneous Memory Management) + * mirror and zone device private memory migration APIs of the kernel. + * Userspace programs can register with the driver to mirror their own address + * space and can use the device to read/write any valid virtual address. + */ +#include <linux/init.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/mutex.h> +#include <linux/rwsem.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/highmem.h> +#include <linux/delay.h> +#include <linux/pagemap.h> +#include <linux/hmm.h> +#include <linux/vmalloc.h> +#include <linux/swap.h> +#include <linux/swapops.h> +#include <linux/sched/mm.h> +#include <linux/platform_device.h> + +#include <uapi/linux/test_hmm.h> + +#define DMIRROR_NDEVICES 2 +#define DMIRROR_RANGE_FAULT_TIMEOUT 1000 +#define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U) +#define DEVMEM_CHUNKS_RESERVE 16 + +static const struct dev_pagemap_ops dmirror_devmem_ops; +static const struct mmu_interval_notifier_ops dmirror_min_ops; +static dev_t dmirror_dev; +static struct page *dmirror_zero_page; + +struct dmirror_device; + +struct dmirror_bounce { + void *ptr; + unsigned long size; + unsigned long addr; + unsigned long cpages; +}; + +#define DPT_SHIFT PAGE_SHIFT +#define DPT_VALID (1UL << 0) +#define DPT_WRITE (1UL << 1) + +#define DPT_XA_TAG_WRITE 3UL + +static const uint64_t dmirror_hmm_flags[HMM_PFN_FLAG_MAX] = { + [HMM_PFN_VALID] = DPT_VALID, + [HMM_PFN_WRITE] = DPT_WRITE, +}; + +static const uint64_t dmirror_hmm_values[HMM_PFN_VALUE_MAX] = { + [HMM_PFN_NONE] = 0, + [HMM_PFN_ERROR] = 0x10, + [HMM_PFN_SPECIAL] = 0x10, +}; + +/* + * Data structure to track address ranges and register for mmu interval + * notifier updates. + */ +struct dmirror_interval { + struct mmu_interval_notifier notifier; + struct dmirror *dmirror; +}; + +/* + * Data attached to the open device file. + * Note that it might be shared after a fork(). + */ +struct dmirror { + struct dmirror_device *mdevice; + struct xarray pt; + struct mmu_interval_notifier notifier; + struct mutex mutex; +}; + +/* + * ZONE_DEVICE pages for migration and simulating device memory. + */ +struct dmirror_chunk { + struct dev_pagemap pagemap; + struct dmirror_device *mdevice; +}; + +/* + * Per device data. + */ +struct dmirror_device { + struct cdev cdevice; + struct hmm_devmem *devmem; + + unsigned int devmem_capacity; + unsigned int devmem_count; + struct dmirror_chunk **devmem_chunks; + struct mutex devmem_lock; /* protects the above */ + + unsigned long calloc; + unsigned long cfree; + struct page *free_pages; + spinlock_t lock; /* protects the above */ +}; + +static struct dmirror_device dmirror_devices[DMIRROR_NDEVICES]; + +static int dmirror_bounce_init(struct dmirror_bounce *bounce, + unsigned long addr, + unsigned long size) +{ + bounce->addr = addr; + bounce->size = size; + bounce->cpages = 0; + bounce->ptr = vmalloc(size); + if (!bounce->ptr) + return -ENOMEM; + return 0; +} + +static void dmirror_bounce_fini(struct dmirror_bounce *bounce) +{ + vfree(bounce->ptr); +} + +static int dmirror_fops_open(struct inode *inode, struct file *filp) +{ + struct cdev *cdev = inode->i_cdev; + struct dmirror *dmirror; + int ret; + + /* Mirror this process address space */ + dmirror = kzalloc(sizeof(*dmirror), GFP_KERNEL); + if (dmirror == NULL) + return -ENOMEM; + + dmirror->mdevice = container_of(cdev, struct dmirror_device, cdevice); + mutex_init(&dmirror->mutex); + xa_init(&dmirror->pt); + + ret = mmu_interval_notifier_insert(&dmirror->notifier, current->mm, + 0, ULONG_MAX & PAGE_MASK, &dmirror_min_ops); + if (ret) { + kfree(dmirror); + return ret; + } + + filp->private_data = dmirror; + return 0; +} + +static int dmirror_fops_release(struct inode *inode, struct file *filp) +{ + struct dmirror *dmirror = filp->private_data; + + mmu_interval_notifier_remove(&dmirror->notifier); + xa_destroy(&dmirror->pt); + kfree(dmirror); + return 0; +} + +static inline struct dmirror_device *dmirror_page_to_device(struct page *page) + +{ + return container_of(page->pgmap, struct dmirror_chunk, + pagemap)->mdevice; +} + +static int dmirror_do_fault(struct dmirror *dmirror, struct hmm_range *range) +{ + uint64_t *pfns = range->pfns; + unsigned long pfn; + + for (pfn = (range->start >> PAGE_SHIFT); + pfn < (range->end >> PAGE_SHIFT); + pfn++, pfns++) { + struct page *page; + void *entry; + + /* + * Since we asked for hmm_range_fault() to populate pages, + * it shouldn't return an error entry on success. + */ + WARN_ON(*pfns == range->values[HMM_PFN_ERROR]); + + page = hmm_device_entry_to_page(range, *pfns); + WARN_ON(!page); + + entry = page; + if (*pfns & range->flags[HMM_PFN_WRITE]) + entry = xa_tag_pointer(entry, DPT_XA_TAG_WRITE); + else if (range->default_flags & range->flags[HMM_PFN_WRITE]) + return -EFAULT; + entry = xa_store(&dmirror->pt, pfn, entry, GFP_ATOMIC); + if (xa_is_err(entry)) + return xa_err(entry); + } + + return 0; +} + +static void dmirror_do_update(struct dmirror *dmirror, unsigned long start, + unsigned long end) +{ + unsigned long pfn; + + /* + * The XArray doesn't hold references to pages since it relies on + * the mmu notifier to clear page pointers when they become stale. + * Therefore, it is OK to just clear the entry. + */ + for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) + xa_erase(&dmirror->pt, pfn); +} + +static bool dmirror_interval_invalidate(struct mmu_interval_notifier *mni, + const struct mmu_notifier_range *range, + unsigned long cur_seq) +{ + struct dmirror *dmirror = container_of(mni, struct dmirror, notifier); + + /* + * If everything is being invalidated, just return since the + * mmget_not_zero() will protect the device page table from + * being used if the file remains open after the process dies + * (e.g., dup() or fork()). + */ + if (range->start == 0 && range->end == ULONG_MAX) + return true; + + if (mmu_notifier_range_blockable(range)) + mutex_lock(&dmirror->mutex); + else if (!mutex_trylock(&dmirror->mutex)) + return false; + + mmu_interval_set_seq(mni, cur_seq); + dmirror_do_update(dmirror, range->start, range->end); + + mutex_unlock(&dmirror->mutex); + return true; +} + +static const struct mmu_interval_notifier_ops dmirror_min_ops = { + .invalidate = dmirror_interval_invalidate, +}; + +static int dmirror_range_fault(struct dmirror *dmirror, + struct hmm_range *range) +{ + struct mm_struct *mm = dmirror->notifier.mm; + unsigned long timeout = + jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); + int ret; + + while (true) { + long count; + + if (time_after(jiffies, timeout)) { + ret = -EBUSY; + goto out; + } + + range->notifier_seq = mmu_interval_read_begin(range->notifier); + down_read(&mm->mmap_sem); + count = hmm_range_fault(range); + up_read(&mm->mmap_sem); + if (count <= 0) { + if (count == 0 || count == -EBUSY) + continue; + ret = count; + goto out; + } + + mutex_lock(&dmirror->mutex); + if (mmu_interval_read_retry(range->notifier, + range->notifier_seq)) { + mutex_unlock(&dmirror->mutex); + continue; + } + break; + } + + ret = dmirror_do_fault(dmirror, range); + + mutex_unlock(&dmirror->mutex); +out: + return ret; +} + +static int dmirror_fault(struct dmirror *dmirror, unsigned long start, + unsigned long end, bool write) +{ + struct mm_struct *mm = dmirror->notifier.mm; + unsigned long addr; + uint64_t pfns[64]; + struct hmm_range range = { + .notifier = &dmirror->notifier, + .pfns = pfns, + .flags = dmirror_hmm_flags, + .values = dmirror_hmm_values, + .pfn_shift = DPT_SHIFT, + .pfn_flags_mask = 0, + .default_flags = dmirror_hmm_flags[HMM_PFN_VALID] | + (write ? dmirror_hmm_flags[HMM_PFN_WRITE] : 0), + .dev_private_owner = dmirror->mdevice, + }; + int ret = 0; + + /* Since the mm is for the mirrored process, get a reference first. */ + if (!mmget_not_zero(mm)) + return 0; + + for (addr = start; addr < end; addr = range.end) { + range.start = addr; + range.end = min(addr + (ARRAY_SIZE(pfns) << PAGE_SHIFT), end); + + ret = dmirror_range_fault(dmirror, &range); + if (ret) + break; + } + + mmput(mm); + return ret; +} + +static int dmirror_do_read(struct dmirror *dmirror, unsigned long start, + unsigned long end, struct dmirror_bounce *bounce) +{ + unsigned long pfn; + void *ptr; + + ptr = bounce->ptr + ((start - bounce->addr) & PAGE_MASK); + + for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) { + void *entry; + struct page *page; + void *tmp; + + entry = xa_load(&dmirror->pt, pfn); + page = xa_untag_pointer(entry); + if (!page) + return -ENOENT; + + tmp = kmap(page); + memcpy(ptr, tmp, PAGE_SIZE); + kunmap(page); + + ptr += PAGE_SIZE; + bounce->cpages++; + } + + return 0; +} + +static int dmirror_read(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd) +{ + struct dmirror_bounce bounce; + unsigned long start, end; + unsigned long size = cmd->npages << PAGE_SHIFT; + int ret; + + start = cmd->addr; + end = start + size; + if (end < start) + return -EINVAL; + + ret = dmirror_bounce_init(&bounce, start, size); + if (ret) + return ret; + + while (1) { + mutex_lock(&dmirror->mutex); + ret = dmirror_do_read(dmirror, start, end, &bounce); + mutex_unlock(&dmirror->mutex); + if (ret != -ENOENT) + break; + + start = cmd->addr + (bounce.cpages << PAGE_SHIFT); + ret = dmirror_fault(dmirror, start, end, false); + if (ret) + break; + cmd->faults++; + } + + if (ret == 0) + ret = copy_to_user(u64_to_user_ptr(cmd->ptr), bounce.ptr, + bounce.size); + cmd->cpages = bounce.cpages; + dmirror_bounce_fini(&bounce); + return ret; +} + +static int dmirror_do_write(struct dmirror *dmirror, unsigned long start, + unsigned long end, struct dmirror_bounce *bounce) +{ + unsigned long pfn; + void *ptr; + + ptr = bounce->ptr + ((start - bounce->addr) & PAGE_MASK); + + for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) { + void *entry; + struct page *page; + void *tmp; + + entry = xa_load(&dmirror->pt, pfn); + page = xa_untag_pointer(entry); + if (!page || xa_pointer_tag(entry) != DPT_XA_TAG_WRITE) + return -ENOENT; + + tmp = kmap(page); + memcpy(tmp, ptr, PAGE_SIZE); + kunmap(page); + + ptr += PAGE_SIZE; + bounce->cpages++; + } + + return 0; +} + +static int dmirror_write(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd) +{ + struct dmirror_bounce bounce; + unsigned long start, end; + unsigned long size = cmd->npages << PAGE_SHIFT; + int ret; + + start = cmd->addr; + end = start + size; + if (end < start) + return -EINVAL; + + ret = dmirror_bounce_init(&bounce, start, size); + if (ret) + return ret; + ret = copy_from_user(bounce.ptr, u64_to_user_ptr(cmd->ptr), + bounce.size); + if (ret) + return ret; + + while (1) { + mutex_lock(&dmirror->mutex); + ret = dmirror_do_write(dmirror, start, end, &bounce); + mutex_unlock(&dmirror->mutex); + if (ret != -ENOENT) + break; + + start = cmd->addr + (bounce.cpages << PAGE_SHIFT); + ret = dmirror_fault(dmirror, start, end, true); + if (ret) + break; + cmd->faults++; + } + + cmd->cpages = bounce.cpages; + dmirror_bounce_fini(&bounce); + return ret; +} + +static bool dmirror_allocate_chunk(struct dmirror_device *mdevice, + struct page **ppage) +{ + struct dmirror_chunk *devmem; + struct resource *res; + unsigned long pfn; + unsigned long pfn_first; + unsigned long pfn_last; + void *ptr; + + mutex_lock(&mdevice->devmem_lock); + + if (mdevice->devmem_count == mdevice->devmem_capacity) { + struct dmirror_chunk **new_chunks; + unsigned int new_capacity; + + new_capacity = mdevice->devmem_capacity + + DEVMEM_CHUNKS_RESERVE; + new_chunks = krealloc(mdevice->devmem_chunks, + sizeof(new_chunks[0]) * new_capacity, + GFP_KERNEL); + if (!new_chunks) + goto err; + mdevice->devmem_capacity = new_capacity; + mdevice->devmem_chunks = new_chunks; + } + + res = request_free_mem_region(&iomem_resource, DEVMEM_CHUNK_SIZE, + "hmm_dmirror"); + if (IS_ERR(res)) + goto err; + + devmem = kzalloc(sizeof(*devmem), GFP_KERNEL); + if (!devmem) + goto err; + + devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; + devmem->pagemap.res = *res; + devmem->pagemap.ops = &dmirror_devmem_ops; + devmem->pagemap.owner = mdevice; + + ptr = memremap_pages(&devmem->pagemap, numa_node_id()); + if (IS_ERR(ptr)) + goto err_free; + + devmem->mdevice = mdevice; + pfn_first = devmem->pagemap.res.start >> PAGE_SHIFT; + pfn_last = pfn_first + + (resource_size(&devmem->pagemap.res) >> PAGE_SHIFT); + mdevice->devmem_chunks[mdevice->devmem_count++] = devmem; + + mutex_unlock(&mdevice->devmem_lock); + + pr_info("added new %u MB chunk (total %u chunks, %u MB) PFNs [0x%lx 0x%lx)\n", + DEVMEM_CHUNK_SIZE / (1024 * 1024), + mdevice->devmem_count, + mdevice->devmem_count * (DEVMEM_CHUNK_SIZE / (1024 * 1024)), + pfn_first, pfn_last); + + spin_lock(&mdevice->lock); + for (pfn = pfn_first; pfn < pfn_last; pfn++) { + struct page *page = pfn_to_page(pfn); + + page->zone_device_data = mdevice->free_pages; + mdevice->free_pages = page; + } + if (ppage) { + *ppage = mdevice->free_pages; + mdevice->free_pages = (*ppage)->zone_device_data; + mdevice->calloc++; + } + spin_unlock(&mdevice->lock); + + return true; + +err_free: + kfree(devmem); +err: + mutex_unlock(&mdevice->devmem_lock); + return false; +} + +static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice) +{ + struct page *dpage = NULL; + struct page *rpage; + + /* + * This is a fake device so we alloc real system memory to store + * our device memory. + */ + rpage = alloc_page(GFP_HIGHUSER); + if (!rpage) + return NULL; + + spin_lock(&mdevice->lock); + + if (mdevice->free_pages) { + dpage = mdevice->free_pages; + mdevice->free_pages = dpage->zone_device_data; + mdevice->calloc++; + spin_unlock(&mdevice->lock); + } else { + spin_unlock(&mdevice->lock); + if (!dmirror_allocate_chunk(mdevice, &dpage)) + goto error; + } + + dpage->zone_device_data = rpage; + get_page(dpage); + lock_page(dpage); + return dpage; + +error: + __free_page(rpage); + return NULL; +} + +static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args, + struct dmirror *dmirror) +{ + struct dmirror_device *mdevice = dmirror->mdevice; + const unsigned long *src = args->src; + unsigned long *dst = args->dst; + unsigned long addr; + + for (addr = args->start; addr < args->end; addr += PAGE_SIZE, + src++, dst++) { + struct page *spage; + struct page *dpage; + struct page *rpage; + + if (!(*src & MIGRATE_PFN_MIGRATE)) + continue; + + /* + * Note that spage might be NULL which is OK since it is an + * unallocated pte_none() or read-only zero page. + */ + 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; + + rpage = dpage->zone_device_data; + if (spage) + copy_highpage(rpage, spage); + else + clear_highpage(rpage); + + /* + * Normally, a device would use the page->zone_device_data to + * point to the mirror but here we use it to hold the page for + * the simulated device memory and that page holds the pointer + * to the mirror. + */ + rpage->zone_device_data = dmirror; + + *dst = migrate_pfn(page_to_pfn(dpage)) | + MIGRATE_PFN_LOCKED; + if ((*src & MIGRATE_PFN_WRITE) || + (!spage && args->vma->vm_flags & VM_WRITE)) + *dst |= MIGRATE_PFN_WRITE; + } +} + +static int dmirror_migrate_finalize_and_map(struct migrate_vma *args, + struct dmirror *dmirror) +{ + unsigned long start = args->start; + unsigned long end = args->end; + const unsigned long *src = args->src; + const unsigned long *dst = args->dst; + unsigned long pfn; + + /* Map the migrated pages into the device's page tables. */ + mutex_lock(&dmirror->mutex); + + for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++, + src++, dst++) { + struct page *dpage; + void *entry; + + if (!(*src & MIGRATE_PFN_MIGRATE)) + continue; + + dpage = migrate_pfn_to_page(*dst); + 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; + if (*dst & MIGRATE_PFN_WRITE) + entry = xa_tag_pointer(entry, DPT_XA_TAG_WRITE); + entry = xa_store(&dmirror->pt, pfn, entry, GFP_ATOMIC); + if (xa_is_err(entry)) + return xa_err(entry); + } + + mutex_unlock(&dmirror->mutex); + return 0; +} + +static int dmirror_migrate(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]; + struct dmirror_bounce bounce; + 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; + + down_read(&mm->mmap_sem); + for (addr = start; addr < end; addr = next) { + vma = find_vma(mm, addr); + if (!vma || addr < vma->vm_start) { + 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.src_owner = NULL; + ret = migrate_vma_setup(&args); + if (ret) + goto out; + + dmirror_migrate_alloc_and_copy(&args, dmirror); + migrate_vma_pages(&args); + dmirror_migrate_finalize_and_map(&args, dmirror); + migrate_vma_finalize(&args); + } + up_read(&mm->mmap_sem); + mmput(mm); + + /* Return the migrated data for verification. */ + ret = dmirror_bounce_init(&bounce, start, size); + if (ret) + return ret; + 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); + cmd->cpages = bounce.cpages; + dmirror_bounce_fini(&bounce); + return ret; + +out: + up_read(&mm->mmap_sem); + mmput(mm); + return ret; +} + +static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range, + unsigned char *perm, uint64_t entry) +{ + struct page *page; + + if (entry == range->values[HMM_PFN_ERROR]) { + *perm = HMM_DMIRROR_PROT_ERROR; + return; + } + page = hmm_device_entry_to_page(range, entry); + if (!page) { + *perm = HMM_DMIRROR_PROT_NONE; + return; + } + if (is_device_private_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_PRIVATE_LOCAL; + else + *perm = HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE; + } else if (is_zero_pfn(page_to_pfn(page))) + *perm = HMM_DMIRROR_PROT_ZERO; + else + *perm = HMM_DMIRROR_PROT_NONE; + if (entry & range->flags[HMM_PFN_WRITE]) + *perm |= HMM_DMIRROR_PROT_WRITE; + else + *perm |= HMM_DMIRROR_PROT_READ; +} + +static bool dmirror_snapshot_invalidate(struct mmu_interval_notifier *mni, + const struct mmu_notifier_range *range, + unsigned long cur_seq) +{ + struct dmirror_interval *dmi = + container_of(mni, struct dmirror_interval, notifier); + struct dmirror *dmirror = dmi->dmirror; + + if (mmu_notifier_range_blockable(range)) + mutex_lock(&dmirror->mutex); + else if (!mutex_trylock(&dmirror->mutex)) + return false; + + /* + * Snapshots only need to set the sequence number since any + * invalidation in the interval invalidates the whole snapshot. + */ + mmu_interval_set_seq(mni, cur_seq); + + mutex_unlock(&dmirror->mutex); + return true; +} + +static const struct mmu_interval_notifier_ops dmirror_mrn_ops = { + .invalidate = dmirror_snapshot_invalidate, +}; + +static int dmirror_range_snapshot(struct dmirror *dmirror, + struct hmm_range *range, + unsigned char *perm) +{ + struct mm_struct *mm = dmirror->notifier.mm; + struct dmirror_interval notifier; + unsigned long timeout = + jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); + unsigned long i; + unsigned long n; + int ret = 0; + + notifier.dmirror = dmirror; + range->notifier = ¬ifier.notifier; + + ret = mmu_interval_notifier_insert(range->notifier, mm, + range->start, range->end - range->start, + &dmirror_mrn_ops); + if (ret) + return ret; + + while (true) { + long count; + + if (time_after(jiffies, timeout)) { + ret = -EBUSY; + goto out; + } + + range->notifier_seq = mmu_interval_read_begin(range->notifier); + + down_read(&mm->mmap_sem); + count = hmm_range_fault(range); + up_read(&mm->mmap_sem); + if (count <= 0) { + if (count == 0 || count == -EBUSY) + continue; + ret = count; + goto out; + } + + mutex_lock(&dmirror->mutex); + if (mmu_interval_read_retry(range->notifier, + range->notifier_seq)) { + mutex_unlock(&dmirror->mutex); + continue; + } + break; + } + + n = (range->end - range->start) >> PAGE_SHIFT; + for (i = 0; i < n; i++) + dmirror_mkentry(dmirror, range, perm + i, range->pfns[i]); + + mutex_unlock(&dmirror->mutex); +out: + mmu_interval_notifier_remove(range->notifier); + return ret; +} + +static int dmirror_snapshot(struct dmirror *dmirror, + struct hmm_dmirror_cmd *cmd) +{ + struct mm_struct *mm = dmirror->notifier.mm; + unsigned long start, end; + unsigned long size = cmd->npages << PAGE_SHIFT; + unsigned long addr; + unsigned long next; + uint64_t pfns[64]; + unsigned char perm[64]; + char __user *uptr; + struct hmm_range range = { + .pfns = pfns, + .flags = dmirror_hmm_flags, + .values = dmirror_hmm_values, + .pfn_shift = DPT_SHIFT, + .pfn_flags_mask = 0, + .dev_private_owner = dmirror->mdevice, + }; + int ret = 0; + + 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; + + /* + * Register a temporary notifier to detect invalidations even if it + * overlaps with other mmu_interval_notifiers. + */ + uptr = u64_to_user_ptr(cmd->ptr); + for (addr = start; addr < end; addr = next) { + unsigned long n; + + next = min(addr + (ARRAY_SIZE(pfns) << PAGE_SHIFT), end); + range.start = addr; + range.end = next; + + ret = dmirror_range_snapshot(dmirror, &range, perm); + if (ret) + break; + + n = (range.end - range.start) >> PAGE_SHIFT; + ret = copy_to_user(uptr, perm, n); + if (ret) + break; + + cmd->cpages += n; + uptr += n; + } + mmput(mm); + + return ret; +} + +static long dmirror_fops_unlocked_ioctl(struct file *filp, + unsigned int command, + unsigned long arg) +{ + void __user *uarg = (void __user *)arg; + struct hmm_dmirror_cmd cmd; + struct dmirror *dmirror; + int ret; + + dmirror = filp->private_data; + if (!dmirror) + return -EINVAL; + + ret = copy_from_user(&cmd, uarg, sizeof(cmd)); + if (ret) + return ret; + + if (cmd.addr & ~PAGE_MASK) + return -EINVAL; + if (cmd.addr >= (cmd.addr + (cmd.npages << PAGE_SHIFT))) + return -EINVAL; + + cmd.cpages = 0; + cmd.faults = 0; + + switch (command) { + case HMM_DMIRROR_READ: + ret = dmirror_read(dmirror, &cmd); + break; + + case HMM_DMIRROR_WRITE: + ret = dmirror_write(dmirror, &cmd); + break; + + case HMM_DMIRROR_MIGRATE: + ret = dmirror_migrate(dmirror, &cmd); + break; + + case HMM_DMIRROR_SNAPSHOT: + ret = dmirror_snapshot(dmirror, &cmd); + break; + + default: + return -EINVAL; + } + if (ret) + return ret; + + return copy_to_user(uarg, &cmd, sizeof(cmd)); +} + +static const struct file_operations dmirror_fops = { + .open = dmirror_fops_open, + .release = dmirror_fops_release, + .unlocked_ioctl = dmirror_fops_unlocked_ioctl, + .llseek = default_llseek, + .owner = THIS_MODULE, +}; + +static void dmirror_devmem_free(struct page *page) +{ + struct page *rpage = page->zone_device_data; + struct dmirror_device *mdevice; + + if (rpage) + __free_page(rpage); + + mdevice = dmirror_page_to_device(page); + + spin_lock(&mdevice->lock); + mdevice->cfree++; + page->zone_device_data = mdevice->free_pages; + mdevice->free_pages = page; + spin_unlock(&mdevice->lock); +} + +static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args, + struct dmirror_device *mdevice) +{ + 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); + copy_highpage(dpage, spage); + *dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; + if (*src & MIGRATE_PFN_WRITE) + *dst |= MIGRATE_PFN_WRITE; + } + 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; + unsigned long src_pfns; + unsigned long dst_pfns; + struct page *rpage; + struct dmirror *dmirror; + vm_fault_t ret; + + /* + * Normally, a device would use the page->zone_device_data to point to + * the mirror but here we use it to hold the page for the simulated + * device memory and that page holds the pointer to the mirror. + */ + rpage = vmf->page->zone_device_data; + dmirror = rpage->zone_device_data; + + /* FIXME demonstrate how we can adjust migrate range */ + args.vma = vmf->vma; + args.start = vmf->address; + args.end = args.start + PAGE_SIZE; + args.src = &src_pfns; + args.dst = &dst_pfns; + args.src_owner = dmirror->mdevice; + + if (migrate_vma_setup(&args)) + return VM_FAULT_SIGBUS; + + ret = dmirror_devmem_fault_alloc_and_copy(&args, dmirror->mdevice); + if (ret) + return ret; + migrate_vma_pages(&args); + dmirror_devmem_fault_finalize_and_map(&args, dmirror); + migrate_vma_finalize(&args); + return 0; +} + +static const struct dev_pagemap_ops dmirror_devmem_ops = { + .page_free = dmirror_devmem_free, + .migrate_to_ram = dmirror_devmem_fault, +}; + +static int dmirror_device_init(struct dmirror_device *mdevice, int id) +{ + dev_t dev; + int ret; + + dev = MKDEV(MAJOR(dmirror_dev), id); + mutex_init(&mdevice->devmem_lock); + spin_lock_init(&mdevice->lock); + + cdev_init(&mdevice->cdevice, &dmirror_fops); + ret = cdev_add(&mdevice->cdevice, dev, 1); + if (ret) + return ret; + + /* Build a list of free ZONE_DEVICE private struct pages */ + dmirror_allocate_chunk(mdevice, NULL); + + return 0; +} + +static void dmirror_device_remove(struct dmirror_device *mdevice) +{ + unsigned int i; + + if (mdevice->devmem_chunks) { + for (i = 0; i < mdevice->devmem_count; i++) { + struct dmirror_chunk *devmem = + mdevice->devmem_chunks[i]; + + memunmap_pages(&devmem->pagemap); + kfree(devmem); + } + kfree(mdevice->devmem_chunks); + } + + cdev_del(&mdevice->cdevice); +} + +static int __init hmm_dmirror_init(void) +{ + int ret; + int id; + + ret = alloc_chrdev_region(&dmirror_dev, 0, DMIRROR_NDEVICES, + "HMM_DMIRROR"); + if (ret) + goto err_unreg; + + for (id = 0; id < DMIRROR_NDEVICES; id++) { + ret = dmirror_device_init(dmirror_devices + id, id); + if (ret) + goto err_chrdev; + } + + /* + * Allocate a zero page to simulate a reserved page of device private + * memory which is always zero. The zero_pfn page isn't used just to + * make the code here simpler (i.e., we need a struct page for it). + */ + dmirror_zero_page = alloc_page(GFP_HIGHUSER | __GFP_ZERO); + if (!dmirror_zero_page) + goto err_chrdev; + + pr_info("HMM test module loaded. This is only for testing HMM.\n"); + return 0; + +err_chrdev: + while (--id >= 0) + dmirror_device_remove(dmirror_devices + id); + unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES); +err_unreg: + return ret; +} + +static void __exit hmm_dmirror_exit(void) +{ + int id; + + if (dmirror_zero_page) + __free_page(dmirror_zero_page); + for (id = 0; id < DMIRROR_NDEVICES; id++) + dmirror_device_remove(dmirror_devices + id); + unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES); +} + +module_init(hmm_dmirror_init); +module_exit(hmm_dmirror_exit); +MODULE_LICENSE("GPL");
Add some basic stand alone self tests for HMM. The test program and shell scripts use the test_hmm.ko driver to exercise HMM functionality in the kernel.
Signed-off-by: Ralph Campbell rcampbell@nvidia.com --- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 3 + tools/testing/selftests/vm/config | 2 + tools/testing/selftests/vm/hmm-tests.c | 1353 ++++++++++++++++++++++++ tools/testing/selftests/vm/run_vmtests | 16 + tools/testing/selftests/vm/test_hmm.sh | 97 ++ 6 files changed, 1472 insertions(+) create mode 100644 tools/testing/selftests/vm/hmm-tests.c create mode 100755 tools/testing/selftests/vm/test_hmm.sh
diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index 31b3c98b6d34..3054565b3f07 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -14,3 +14,4 @@ virtual_address_range gup_benchmark va_128TBswitch map_fixed_noreplace +hmm-tests diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index 7f9a8a8c31da..3fadab99d991 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -7,6 +7,7 @@ CFLAGS = -Wall -I ../../../../usr/include $(EXTRA_CFLAGS) LDLIBS = -lrt TEST_GEN_FILES = compaction_test TEST_GEN_FILES += gup_benchmark +TEST_GEN_FILES += hmm-tests TEST_GEN_FILES += hugepage-mmap TEST_GEN_FILES += hugepage-shm TEST_GEN_FILES += map_hugetlb @@ -31,6 +32,8 @@ TEST_FILES := test_vmalloc.sh KSFT_KHDR_INSTALL := 1 include ../lib.mk
+$(OUTPUT)/hmm-tests: LDLIBS += -lhugetlbfs -lpthread + $(OUTPUT)/userfaultfd: LDLIBS += -lpthread
$(OUTPUT)/mlock-random-test: LDLIBS += -lcap diff --git a/tools/testing/selftests/vm/config b/tools/testing/selftests/vm/config index 93b90a9b1eeb..6b64d61ec455 100644 --- a/tools/testing/selftests/vm/config +++ b/tools/testing/selftests/vm/config @@ -1,3 +1,5 @@ CONFIG_SYSVIPC=y CONFIG_USERFAULTFD=y CONFIG_TEST_VMALLOC=m +CONFIG_DEVICE_PRIVATE=y +CONFIG_TEST_HMM=y diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c new file mode 100644 index 000000000000..033a12c7ab5b --- /dev/null +++ b/tools/testing/selftests/vm/hmm-tests.c @@ -0,0 +1,1353 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * HMM stands for Heterogeneous Memory Management, it is a helper layer inside + * the linux kernel to help device drivers mirror a process address space in + * the device. This allows the device to use the same address space which + * makes communication and data exchange a lot easier. + * + * This framework's sole purpose is to exercise various code paths inside + * the kernel to make sure that HMM performs as expected and to flush out any + * bugs. + */ + +#include "../kselftest_harness.h" + +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <unistd.h> +#include <strings.h> +#include <time.h> +#include <pthread.h> +#include <hugetlbfs.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/mman.h> +#include <sys/ioctl.h> +#include <linux/test_hmm.h> + +struct hmm_buffer { + void *ptr; + void *mirror; + unsigned long size; + int fd; + uint64_t cpages; + uint64_t faults; +}; + +#define TWOMEG (1 << 21) +#define HMM_BUFFER_SIZE (1024 << 12) +#define HMM_PATH_MAX 64 +#define NTIMES 256 + +#define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1))) + +FIXTURE(hmm) +{ + int fd; + unsigned int page_size; + unsigned int page_shift; +}; + +FIXTURE(hmm2) +{ + int fd0; + int fd1; + unsigned int page_size; + unsigned int page_shift; +}; + +static int hmm_open(int unit) +{ + char pathname[HMM_PATH_MAX]; + int fd; + + snprintf(pathname, sizeof(pathname), "/dev/hmm_dmirror%d", unit); + fd = open(pathname, O_RDWR, 0); + if (fd < 0) + fprintf(stderr, "could not open hmm dmirror driver (%s)\n", + pathname); + return fd; +} + +FIXTURE_SETUP(hmm) +{ + self->page_size = sysconf(_SC_PAGE_SIZE); + self->page_shift = ffs(self->page_size) - 1; + + self->fd = hmm_open(0); + ASSERT_GE(self->fd, 0); +} + +FIXTURE_SETUP(hmm2) +{ + self->page_size = sysconf(_SC_PAGE_SIZE); + self->page_shift = ffs(self->page_size) - 1; + + self->fd0 = hmm_open(0); + ASSERT_GE(self->fd0, 0); + self->fd1 = hmm_open(1); + ASSERT_GE(self->fd1, 0); +} + +FIXTURE_TEARDOWN(hmm) +{ + int ret = close(self->fd); + + ASSERT_EQ(ret, 0); + self->fd = -1; +} + +FIXTURE_TEARDOWN(hmm2) +{ + int ret = close(self->fd0); + + ASSERT_EQ(ret, 0); + self->fd0 = -1; + + ret = close(self->fd1); + ASSERT_EQ(ret, 0); + self->fd1 = -1; +} + +static int hmm_dmirror_cmd(int fd, + unsigned long request, + struct hmm_buffer *buffer, + unsigned long npages) +{ + struct hmm_dmirror_cmd cmd; + int ret; + + /* Simulate a device reading system memory. */ + cmd.addr = (__u64)buffer->ptr; + cmd.ptr = (__u64)buffer->mirror; + cmd.npages = npages; + + for (;;) { + ret = ioctl(fd, request, &cmd); + if (ret == 0) + break; + if (errno == EINTR) + continue; + return -errno; + } + buffer->cpages = cmd.cpages; + buffer->faults = cmd.faults; + + return 0; +} + +static void hmm_buffer_free(struct hmm_buffer *buffer) +{ + if (buffer == NULL) + return; + + if (buffer->ptr) + munmap(buffer->ptr, buffer->size); + free(buffer->mirror); + free(buffer); +} + +/* + * Create a temporary file that will be deleted on close. + */ +static int hmm_create_file(unsigned long size) +{ + char path[HMM_PATH_MAX]; + int fd; + + strcpy(path, "/tmp"); + fd = open(path, O_TMPFILE | O_EXCL | O_RDWR, 0600); + if (fd >= 0) { + int r; + + do { + r = ftruncate(fd, size); + } while (r == -1 && errno == EINTR); + if (!r) + return fd; + close(fd); + } + return -1; +} + +/* + * Return a random unsigned number. + */ +static unsigned int hmm_random(void) +{ + static int fd = -1; + unsigned int r; + + if (fd < 0) { + fd = open("/dev/urandom", O_RDONLY); + if (fd < 0) { + fprintf(stderr, "%s:%d failed to open /dev/urandom\n", + __FILE__, __LINE__); + return ~0U; + } + } + read(fd, &r, sizeof(r)); + return r; +} + +static void hmm_nanosleep(unsigned int n) +{ + struct timespec t; + + t.tv_sec = 0; + t.tv_nsec = n; + nanosleep(&t, NULL); +} + +/* + * Simple NULL test of device open/close. + */ +TEST_F(hmm, open_close) +{ +} + +/* + * Read private anonymous memory. + */ +TEST_F(hmm, anon_read) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + int *ptr; + int ret; + int val; + + 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 but leave the first two pages + * zero (pte_none and pfn_zero). + */ + i = 2 * self->page_size / sizeof(*ptr); + for (ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Set buffer permission to read-only. */ + ret = mprotect(buffer->ptr, size, PROT_READ); + ASSERT_EQ(ret, 0); + + /* Populate the CPU page table with a special zero page. */ + val = *(int *)(buffer->ptr + self->page_size); + ASSERT_EQ(val, 0); + + /* Simulate a device reading system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_READ, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device read. */ + ptr = buffer->mirror; + for (i = 0; i < 2 * self->page_size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], 0); + for (; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + hmm_buffer_free(buffer); +} + +/* + * Read private anonymous memory which has been protected with + * mprotect() PROT_NONE. + */ +TEST_F(hmm, anon_read_prot) +{ + 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; + + /* Initialize mirror buffer so we can verify it isn't written. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = -i; + + /* Protect buffer from reading. */ + ret = mprotect(buffer->ptr, size, PROT_NONE); + ASSERT_EQ(ret, 0); + + /* Simulate a device reading system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_READ, buffer, npages); + ASSERT_EQ(ret, -EFAULT); + + /* Allow CPU to read the buffer so we can check it. */ + ret = mprotect(buffer->ptr, size, PROT_READ); + ASSERT_EQ(ret, 0); + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + /* 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); +} + +/* + * Write private anonymous memory. + */ +TEST_F(hmm, anon_write) +{ + 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 data that the device will write to buffer->ptr. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device wrote. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + hmm_buffer_free(buffer); +} + +/* + * Write private anonymous memory which has been protected with + * mprotect() PROT_READ. + */ +TEST_F(hmm, anon_write_prot) +{ + 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, + MAP_PRIVATE | MAP_ANONYMOUS, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + + /* Simulate a device reading a zero page of memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_READ, buffer, 1); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, 1); + ASSERT_EQ(buffer->faults, 1); + + /* Initialize data that the device will write to buffer->ptr. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, -EPERM); + + /* Check what the device wrote. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], 0); + + /* Now allow writing and see that the zero page is replaced. */ + ret = mprotect(buffer->ptr, size, PROT_WRITE | PROT_READ); + ASSERT_EQ(ret, 0); + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device wrote. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + hmm_buffer_free(buffer); +} + +/* + * Check that a device writing an anonymous private mapping + * will copy-on-write if a child process inherits the mapping. + */ +TEST_F(hmm, anon_write_child) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + int *ptr; + pid_t pid; + int child_fd; + 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->ptr so we can tell if it is written. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Initialize data that the device will write to buffer->ptr. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = -i; + + pid = fork(); + if (pid == -1) + ASSERT_EQ(pid, 0); + if (pid != 0) { + waitpid(pid, &ret, 0); + ASSERT_EQ(WIFEXITED(ret), 1); + + /* Check that the parent's buffer did not change. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + return; + } + + /* Check that we see the parent's values. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], -i); + + /* The child process needs its own mirror to its own mm. */ + child_fd = hmm_open(0); + ASSERT_GE(child_fd, 0); + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(child_fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device wrote. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], -i); + + close(child_fd); + exit(0); +} + +/* + * Check that a device writing an anonymous shared mapping + * will not copy-on-write if a child process inherits the mapping. + */ +TEST_F(hmm, anon_write_child_shared) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + int *ptr; + pid_t pid; + int child_fd; + 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_SHARED | MAP_ANONYMOUS, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + + /* Initialize buffer->ptr so we can tell if it is written. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Initialize data that the device will write to buffer->ptr. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = -i; + + pid = fork(); + if (pid == -1) + ASSERT_EQ(pid, 0); + if (pid != 0) { + waitpid(pid, &ret, 0); + ASSERT_EQ(WIFEXITED(ret), 1); + + /* Check that the parent's buffer did change. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], -i); + return; + } + + /* Check that we see the parent's values. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], -i); + + /* The child process needs its own mirror to its own mm. */ + child_fd = hmm_open(0); + ASSERT_GE(child_fd, 0); + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(child_fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device wrote. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], -i); + + close(child_fd); + exit(0); +} + +/* + * Write private anonymous huge page. + */ +TEST_F(hmm, anon_write_huge) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + void *old_ptr; + void *map; + int *ptr; + int ret; + + size = 2 * TWOMEG; + + 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); + + size = TWOMEG; + npages = size >> self->page_shift; + map = (void *)ALIGN((uintptr_t)buffer->ptr, size); + ret = madvise(map, size, MADV_HUGEPAGE); + ASSERT_EQ(ret, 0); + old_ptr = buffer->ptr; + buffer->ptr = map; + + /* Initialize data that the device will write to buffer->ptr. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device wrote. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + buffer->ptr = old_ptr; + hmm_buffer_free(buffer); +} + +/* + * Write huge TLBFS page. + */ +TEST_F(hmm, anon_write_hugetlbfs) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + int *ptr; + int ret; + long pagesizes[4]; + int n, idx; + + /* Skip test if we can't allocate a hugetlbfs page. */ + + n = gethugepagesizes(pagesizes, 4); + if (n <= 0) + return; + for (idx = 0; --n > 0; ) { + if (pagesizes[n] < pagesizes[idx]) + idx = n; + } + size = ALIGN(TWOMEG, pagesizes[idx]); + npages = size >> self->page_shift; + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->ptr = get_hugepage_region(size, GHR_STRICT); + if (buffer->ptr == NULL) { + free(buffer); + return; + } + + buffer->fd = -1; + buffer->size = size; + buffer->mirror = malloc(size); + ASSERT_NE(buffer->mirror, NULL); + + /* Initialize data that the device will write to buffer->ptr. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device wrote. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + free_hugepage_region(buffer->ptr); + buffer->ptr = NULL; + hmm_buffer_free(buffer); +} + +/* + * Read mmap'ed file memory. + */ +TEST_F(hmm, file_read) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + int *ptr; + int ret; + int fd; + ssize_t len; + + npages = ALIGN(HMM_BUFFER_SIZE, self->page_size) >> self->page_shift; + ASSERT_NE(npages, 0); + size = npages << self->page_shift; + + fd = hmm_create_file(size); + ASSERT_GE(fd, 0); + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd = fd; + buffer->size = size; + buffer->mirror = malloc(size); + ASSERT_NE(buffer->mirror, NULL); + + /* Write initial contents of the file. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + len = pwrite(fd, buffer->mirror, size, 0); + ASSERT_EQ(len, size); + memset(buffer->mirror, 0, size); + + buffer->ptr = mmap(NULL, size, + PROT_READ, + MAP_SHARED, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + + /* Simulate a device reading system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_READ, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* 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); +} + +/* + * Write mmap'ed file memory. + */ +TEST_F(hmm, file_write) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + int *ptr; + int ret; + int fd; + ssize_t len; + + npages = ALIGN(HMM_BUFFER_SIZE, self->page_size) >> self->page_shift; + ASSERT_NE(npages, 0); + size = npages << self->page_shift; + + fd = hmm_create_file(size); + ASSERT_GE(fd, 0); + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd = fd; + buffer->size = size; + buffer->mirror = malloc(size); + ASSERT_NE(buffer->mirror, NULL); + + buffer->ptr = mmap(NULL, size, + PROT_READ | PROT_WRITE, + MAP_SHARED, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + + /* Initialize data that the device will write to buffer->ptr. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device wrote. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + /* Check that the device also wrote the file. */ + len = pread(fd, buffer->mirror, size, 0); + ASSERT_EQ(len, size); + 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. + */ +TEST_F(hmm, migrate) +{ + 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; + + /* Migrate memory to device. */ + 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); +} + +/* + * Migrate anonymous memory to device private memory and fault it back to system + * memory. + */ +TEST_F(hmm, migrate_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; + + /* Migrate memory to device. */ + 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); + + /* Fault pages back to system memory and check them. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + hmm_buffer_free(buffer); +} + +/* + * Try to migrate various memory types to device private memory. + */ +TEST_F(hmm2, migrate_mixed) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + int *ptr; + unsigned char *p; + int ret; + int val; + + npages = 6; + 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); + + /* Reserve a range of addresses. */ + buffer->ptr = mmap(NULL, size, + PROT_NONE, + MAP_PRIVATE | MAP_ANONYMOUS, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + p = buffer->ptr; + + /* Now try to migrate everything to device 1. */ + ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, 6); + + /* Punch a hole after the first page address. */ + ret = munmap(buffer->ptr + self->page_size, self->page_size); + 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); + ASSERT_EQ(ret, -EINVAL); + + /* Page 2 will be a read-only zero page. */ + ret = mprotect(buffer->ptr + 2 * self->page_size, self->page_size, + PROT_READ); + ASSERT_EQ(ret, 0); + ptr = (int *)(buffer->ptr + 2 * self->page_size); + val = *ptr + 3; + ASSERT_EQ(val, 3); + + /* Page 3 will be read-only. */ + ret = mprotect(buffer->ptr + 3 * self->page_size, self->page_size, + PROT_READ | PROT_WRITE); + ASSERT_EQ(ret, 0); + ptr = (int *)(buffer->ptr + 3 * self->page_size); + *ptr = val; + ret = mprotect(buffer->ptr + 3 * self->page_size, self->page_size, + PROT_READ); + ASSERT_EQ(ret, 0); + + /* Page 4 will be read-write. */ + ret = mprotect(buffer->ptr + 4 * self->page_size, self->page_size, + PROT_READ | PROT_WRITE); + ASSERT_EQ(ret, 0); + ptr = (int *)(buffer->ptr + 4 * self->page_size); + *ptr = val; + + /* 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); + ASSERT_EQ(ret, -ENOENT); + buffer->ptr = p; + + /* Now try to migrate pages 2-3 to device 1. */ + buffer->ptr = p + 2 * self->page_size; + ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, 2); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, 2); + buffer->ptr = p; + + hmm_buffer_free(buffer); +} + +/* + * Migrate anonymous memory to device private memory and fault it back to system + * memory multiple times. + */ +TEST_F(hmm, migrate_multiple) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + unsigned long c; + int *ptr; + int ret; + + npages = ALIGN(HMM_BUFFER_SIZE, self->page_size) >> self->page_shift; + ASSERT_NE(npages, 0); + size = npages << self->page_shift; + + for (c = 0; c < NTIMES; c++) { + 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_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); + + /* Fault pages back to system memory and check them. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + hmm_buffer_free(buffer); + } +} + +/* + * Read anonymous memory multiple times. + */ +TEST_F(hmm, anon_read_multiple) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + unsigned long c; + int *ptr; + int ret; + + npages = ALIGN(HMM_BUFFER_SIZE, self->page_size) >> self->page_shift; + ASSERT_NE(npages, 0); + size = npages << self->page_shift; + + for (c = 0; c < NTIMES; c++) { + 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 + c; + + /* Simulate a device reading system memory. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_READ, buffer, + npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device read. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i + c); + + hmm_buffer_free(buffer); + } +} + +void *unmap_buffer(void *p) +{ + struct hmm_buffer *buffer = p; + + /* Delay for a bit and then unmap buffer while it is being read. */ + hmm_nanosleep(hmm_random() % 32000); + munmap(buffer->ptr + buffer->size / 2, buffer->size / 2); + buffer->ptr = NULL; + + return NULL; +} + +/* + * Try reading anonymous memory while it is being unmapped. + */ +TEST_F(hmm, anon_teardown) +{ + unsigned long npages; + unsigned long size; + unsigned long c; + void *ret; + + npages = ALIGN(HMM_BUFFER_SIZE, self->page_size) >> self->page_shift; + ASSERT_NE(npages, 0); + size = npages << self->page_shift; + + for (c = 0; c < NTIMES; ++c) { + pthread_t thread; + struct hmm_buffer *buffer; + unsigned long i; + int *ptr; + int rc; + + 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 + c; + + rc = pthread_create(&thread, NULL, unmap_buffer, buffer); + ASSERT_EQ(rc, 0); + + /* Simulate a device reading system memory. */ + rc = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_READ, buffer, + npages); + if (rc == 0) { + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device read. */ + for (i = 0, ptr = buffer->mirror; + i < size / sizeof(*ptr); + ++i) + ASSERT_EQ(ptr[i], i + c); + } + + pthread_join(thread, &ret); + hmm_buffer_free(buffer); + } +} + +/* + * Test memory snapshot without faulting in pages accessed by the device. + */ +TEST_F(hmm2, snapshot) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + int *ptr; + unsigned char *p; + unsigned char *m; + int ret; + int val; + + npages = 7; + size = npages << self->page_shift; + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd = -1; + buffer->size = size; + buffer->mirror = malloc(npages); + ASSERT_NE(buffer->mirror, NULL); + + /* Reserve a range of addresses. */ + buffer->ptr = mmap(NULL, size, + PROT_NONE, + MAP_PRIVATE | MAP_ANONYMOUS, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + p = buffer->ptr; + + /* Punch a hole after the first page address. */ + ret = munmap(buffer->ptr + self->page_size, self->page_size); + ASSERT_EQ(ret, 0); + + /* Page 2 will be read-only zero page. */ + ret = mprotect(buffer->ptr + 2 * self->page_size, self->page_size, + PROT_READ); + ASSERT_EQ(ret, 0); + ptr = (int *)(buffer->ptr + 2 * self->page_size); + val = *ptr + 3; + ASSERT_EQ(val, 3); + + /* Page 3 will be read-only. */ + ret = mprotect(buffer->ptr + 3 * self->page_size, self->page_size, + PROT_READ | PROT_WRITE); + ASSERT_EQ(ret, 0); + ptr = (int *)(buffer->ptr + 3 * self->page_size); + *ptr = val; + ret = mprotect(buffer->ptr + 3 * self->page_size, self->page_size, + PROT_READ); + ASSERT_EQ(ret, 0); + + /* Page 4-6 will be read-write. */ + ret = mprotect(buffer->ptr + 4 * self->page_size, 3 * self->page_size, + PROT_READ | PROT_WRITE); + ASSERT_EQ(ret, 0); + ptr = (int *)(buffer->ptr + 4 * self->page_size); + *ptr = val; + + /* 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); + 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); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, 1); + + /* Simulate a device snapshotting CPU pagetables. */ + buffer->ptr = p; + ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_SNAPSHOT, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + /* Check what the device saw. */ + m = buffer->mirror; + ASSERT_EQ(m[0], HMM_DMIRROR_PROT_ERROR); + ASSERT_EQ(m[1], HMM_DMIRROR_PROT_NONE); + 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); + + hmm_buffer_free(buffer); +} + +/* + * Test two devices reading the same memory (double mapped). + */ +TEST_F(hmm2, double_map) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + unsigned long i; + int *ptr; + int ret; + + npages = 6; + size = npages << self->page_shift; + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd = -1; + buffer->size = size; + buffer->mirror = malloc(npages); + ASSERT_NE(buffer->mirror, NULL); + + /* Reserve a range of addresses. */ + 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; + + /* Make region read-only. */ + ret = mprotect(buffer->ptr, size, PROT_READ); + ASSERT_EQ(ret, 0); + + /* Simulate device 0 reading system memory. */ + ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_READ, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device read. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + /* Simulate device 1 reading system memory. */ + ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_READ, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what the device read. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + /* Punch a hole after the first page address. */ + ret = munmap(buffer->ptr + self->page_size, self->page_size); + ASSERT_EQ(ret, 0); + + hmm_buffer_free(buffer); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/vm/run_vmtests b/tools/testing/selftests/vm/run_vmtests index f33714843198..5e82b2574d54 100755 --- a/tools/testing/selftests/vm/run_vmtests +++ b/tools/testing/selftests/vm/run_vmtests @@ -270,4 +270,20 @@ else exitcode=1 fi
+echo "------------------------------------" +echo "running HMM smoke test" +echo "------------------------------------" +./test_hmm.sh smoke +ret_val=$? + +if [ $ret_val -eq 0 ]; then + echo "[PASS]" +elif [ $ret_val -eq $ksft_skip ]; then + echo "[SKIP]" + exitcode=$ksft_skip +else + echo "[FAIL]" + exitcode=1 +fi + exit $exitcode diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftests/vm/test_hmm.sh new file mode 100755 index 000000000000..461e4a99a362 --- /dev/null +++ b/tools/testing/selftests/vm/test_hmm.sh @@ -0,0 +1,97 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (C) 2018 Uladzislau Rezki (Sony) urezki@gmail.com +# +# This is a test script for the kernel test driver to analyse vmalloc +# allocator. Therefore it is just a kernel module loader. You can specify +# and pass different parameters in order to: +# a) analyse performance of vmalloc allocations; +# b) stressing and stability check of vmalloc subsystem. + +TEST_NAME="test_hmm" +DRIVER="test_hmm" + +# 1 if fails +exitcode=1 + +# Kselftest framework requirement - SKIP code is 4. +ksft_skip=4 + +check_test_requirements() +{ + uid=$(id -u) + if [ $uid -ne 0 ]; then + echo "$0: Must be run as root" + exit $ksft_skip + fi + + if ! which modprobe > /dev/null 2>&1; then + echo "$0: You need modprobe installed" + exit $ksft_skip + fi + + if ! modinfo $DRIVER > /dev/null 2>&1; then + echo "$0: You must have the following enabled in your kernel:" + echo "CONFIG_TEST_HMM=m" + exit $ksft_skip + fi +} + +load_driver() +{ + modprobe $DRIVER > /dev/null 2>&1 + 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 + fi +} + +unload_driver() +{ + modprobe -r $DRIVER > /dev/null 2>&1 + rm -f /dev/hmm_dmirror? +} + +run_smoke() +{ + echo "Running smoke test. Note, this test provides basic coverage." + + load_driver + ./hmm-tests + unload_driver +} + +usage() +{ + echo -n "Usage: $0" + echo + echo "Example usage:" + echo + echo "# Shows help message" + echo "./${TEST_NAME}.sh" + echo + echo "# Smoke testing" + echo "./${TEST_NAME}.sh smoke" + echo + exit 0 +} + +function run_test() +{ + if [ $# -eq 0 ]; then + usage + else + if [ "$1" = "smoke" ]; then + run_smoke + else + usage + fi + fi +} + +check_test_requirements +run_test $@ + +exit 0
Add files for HMM selftests.
Signed-off-by: Ralph Campbell rcampbell@nvidia.com --- MAINTAINERS | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS index fcd79fc38928..d9f5869d6cda 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7610,7 +7610,10 @@ L: linux-mm@kvack.org S: Maintained F: mm/hmm* F: include/linux/hmm* +F: include/uapi/linux/test_hmm* F: Documentation/vm/hmm.rst +F: lib/test_hmm* +F: tools/testing/selftests/vm/*hmm*
HOST AP DRIVER M: Jouni Malinen j@w1.fi
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Changes v7 -> v8: Rebased to Jason's rdma/hmm tree, plus Jason's 6 patch series "Small hmm_range_fault() cleanups". Applied a number of changes from Jason's comments.
Changes v6 -> v7: Rebased to linux-5.6.0-rc6 Reverted back to just using mmu_interval_notifier_insert() and making this series only introduce HMM self tests.
Changes v5 -> v6: Rebased to linux-5.5.0-rc6 Refactored mmu interval notifier patches Converted nouveau to use the new mmu interval notifier API
Changes v4 -> v5: Added mmu interval notifier insert/remove/update callable from the invalidate() callback Updated HMM tests to use the new core interval notifier API
Changes v1 -> v4: https://lore.kernel.org/linux-mm/20191104222141.5173-1-rcampbell@nvidia.com
Ralph Campbell (3): mm/hmm/test: add selftest driver for HMM mm/hmm/test: add selftests for HMM MAINTAINERS: add HMM selftests
MAINTAINERS | 3 + include/uapi/linux/test_hmm.h | 59 ++
Isn't UAPI folder supposed to be for user-visible interfaces that follow the rule of non-breaking user space and not for selftests?
Thanks
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
We are at v8 of this series and noboy from the selftests land has commented, can someone help?
Jason
On 3/21/20 2:00 AM, Leon Romanovsky wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Changes v7 -> v8: Rebased to Jason's rdma/hmm tree, plus Jason's 6 patch series "Small hmm_range_fault() cleanups". Applied a number of changes from Jason's comments.
Changes v6 -> v7: Rebased to linux-5.6.0-rc6 Reverted back to just using mmu_interval_notifier_insert() and making this series only introduce HMM self tests.
Changes v5 -> v6: Rebased to linux-5.5.0-rc6 Refactored mmu interval notifier patches Converted nouveau to use the new mmu interval notifier API
Changes v4 -> v5: Added mmu interval notifier insert/remove/update callable from the invalidate() callback Updated HMM tests to use the new core interval notifier API
Changes v1 -> v4: https://lore.kernel.org/linux-mm/20191104222141.5173-1-rcampbell@nvidia.com
Ralph Campbell (3): mm/hmm/test: add selftest driver for HMM mm/hmm/test: add selftests for HMM MAINTAINERS: add HMM selftests
MAINTAINERS | 3 + include/uapi/linux/test_hmm.h | 59 ++
Isn't UAPI folder supposed to be for user-visible interfaces that follow the rule of non-breaking user space and not for selftests?
Thanks
Most of the other kernel module tests seem to invoke the test as part of the module load/init. I'm open to moving it if there is a more appropriate location.
On Sat, Mar 21, 2020 at 10:27:46AM -0700, Ralph Campbell wrote:
On 3/21/20 2:00 AM, Leon Romanovsky wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Changes v7 -> v8: Rebased to Jason's rdma/hmm tree, plus Jason's 6 patch series "Small hmm_range_fault() cleanups". Applied a number of changes from Jason's comments.
Changes v6 -> v7: Rebased to linux-5.6.0-rc6 Reverted back to just using mmu_interval_notifier_insert() and making this series only introduce HMM self tests.
Changes v5 -> v6: Rebased to linux-5.5.0-rc6 Refactored mmu interval notifier patches Converted nouveau to use the new mmu interval notifier API
Changes v4 -> v5: Added mmu interval notifier insert/remove/update callable from the invalidate() callback Updated HMM tests to use the new core interval notifier API
Changes v1 -> v4: https://lore.kernel.org/linux-mm/20191104222141.5173-1-rcampbell@nvidia.com
Ralph Campbell (3): mm/hmm/test: add selftest driver for HMM mm/hmm/test: add selftests for HMM MAINTAINERS: add HMM selftests
MAINTAINERS | 3 + include/uapi/linux/test_hmm.h | 59 ++
Isn't UAPI folder supposed to be for user-visible interfaces that follow the rule of non-breaking user space and not for selftests?
Thanks
Most of the other kernel module tests seem to invoke the test as part of the module load/init. I'm open to moving it if there is a more appropriate location.
Is it even possible to create a user mm_struct and put crazy things in it soley from a kernel module?
Jason
On Sat, Mar 21, 2020 at 06:55:05PM -0300, Jason Gunthorpe wrote:
On Sat, Mar 21, 2020 at 10:27:46AM -0700, Ralph Campbell wrote:
On 3/21/20 2:00 AM, Leon Romanovsky wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Changes v7 -> v8: Rebased to Jason's rdma/hmm tree, plus Jason's 6 patch series "Small hmm_range_fault() cleanups". Applied a number of changes from Jason's comments.
Changes v6 -> v7: Rebased to linux-5.6.0-rc6 Reverted back to just using mmu_interval_notifier_insert() and making this series only introduce HMM self tests.
Changes v5 -> v6: Rebased to linux-5.5.0-rc6 Refactored mmu interval notifier patches Converted nouveau to use the new mmu interval notifier API
Changes v4 -> v5: Added mmu interval notifier insert/remove/update callable from the invalidate() callback Updated HMM tests to use the new core interval notifier API
Changes v1 -> v4: https://lore.kernel.org/linux-mm/20191104222141.5173-1-rcampbell@nvidia.com
Ralph Campbell (3): mm/hmm/test: add selftest driver for HMM mm/hmm/test: add selftests for HMM MAINTAINERS: add HMM selftests
MAINTAINERS | 3 + include/uapi/linux/test_hmm.h | 59 ++
Isn't UAPI folder supposed to be for user-visible interfaces that follow the rule of non-breaking user space and not for selftests?
Thanks
Most of the other kernel module tests seem to invoke the test as part of the module load/init. I'm open to moving it if there is a more appropriate location.
Is it even possible to create a user mm_struct and put crazy things in it soley from a kernel module?
I didn't look very closely of what Ralph did in his patchsets, but from what I know, if you want in-kernel interface, you use in-kernel module, if you want to test user visible uapi, you write application. You don't create new UAPI just to test something in the kernel.
Can kunit help here? https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html
Thanks
Jason
On 3/22/20 1:10 AM, Leon Romanovsky wrote:
On Sat, Mar 21, 2020 at 06:55:05PM -0300, Jason Gunthorpe wrote:
On Sat, Mar 21, 2020 at 10:27:46AM -0700, Ralph Campbell wrote:
On 3/21/20 2:00 AM, Leon Romanovsky wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Changes v7 -> v8: Rebased to Jason's rdma/hmm tree, plus Jason's 6 patch series "Small hmm_range_fault() cleanups". Applied a number of changes from Jason's comments.
Changes v6 -> v7: Rebased to linux-5.6.0-rc6 Reverted back to just using mmu_interval_notifier_insert() and making this series only introduce HMM self tests.
Changes v5 -> v6: Rebased to linux-5.5.0-rc6 Refactored mmu interval notifier patches Converted nouveau to use the new mmu interval notifier API
Changes v4 -> v5: Added mmu interval notifier insert/remove/update callable from the invalidate() callback Updated HMM tests to use the new core interval notifier API
Changes v1 -> v4: https://lore.kernel.org/linux-mm/20191104222141.5173-1-rcampbell@nvidia.com
Ralph Campbell (3): mm/hmm/test: add selftest driver for HMM mm/hmm/test: add selftests for HMM MAINTAINERS: add HMM selftests
MAINTAINERS | 3 + include/uapi/linux/test_hmm.h | 59 ++
Isn't UAPI folder supposed to be for user-visible interfaces that follow the rule of non-breaking user space and not for selftests?
Thanks
Most of the other kernel module tests seem to invoke the test as part of the module load/init. I'm open to moving it if there is a more appropriate location.
Is it even possible to create a user mm_struct and put crazy things in it soley from a kernel module?
I didn't look very closely of what Ralph did in his patchsets, but from what I know, if you want in-kernel interface, you use in-kernel module, if you want to test user visible uapi, you write application. You don't create new UAPI just to test something in the kernel.
Can kunit help here? https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html
Thanks
Jason
The tests are intended to cover hmm_range_fault() and the migrate_vma_setup(), migrate_vma_pages(), and migrate_vma_finalize() kernel functions that a device driver can call to initialize hardware that has its own page tables. An example is a GPU where the code on the GPU sees the same address space as code running on the host CPU. This means the test has to have a user process to create a user process address space and a device driver to simulate some real device driver. The UAPI is for the user level test program to tell the kernel module test driver what to do and return results. The complexity is all around maintaining coherent copies of the user process page tables while hardware and CPUs are accessing the same physical addresses. The pages are not pinned as with most I/O so system activity like pagein/pageout, LRU page reclaim, compaction, and the process calling functions like mmap(), mprotect(), madvise(), fork(), etc. all update the CPU and device page tables and would be very hard to duplicate in a kernel level only KUNIT style of test.
On Sun, Mar 22, 2020 at 10:10:38AM +0200, Leon Romanovsky wrote:
On Sat, Mar 21, 2020 at 06:55:05PM -0300, Jason Gunthorpe wrote:
On Sat, Mar 21, 2020 at 10:27:46AM -0700, Ralph Campbell wrote:
On 3/21/20 2:00 AM, Leon Romanovsky wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Changes v7 -> v8: Rebased to Jason's rdma/hmm tree, plus Jason's 6 patch series "Small hmm_range_fault() cleanups". Applied a number of changes from Jason's comments.
Changes v6 -> v7: Rebased to linux-5.6.0-rc6 Reverted back to just using mmu_interval_notifier_insert() and making this series only introduce HMM self tests.
Changes v5 -> v6: Rebased to linux-5.5.0-rc6 Refactored mmu interval notifier patches Converted nouveau to use the new mmu interval notifier API
Changes v4 -> v5: Added mmu interval notifier insert/remove/update callable from the invalidate() callback Updated HMM tests to use the new core interval notifier API
Changes v1 -> v4: https://lore.kernel.org/linux-mm/20191104222141.5173-1-rcampbell@nvidia.com
Ralph Campbell (3): mm/hmm/test: add selftest driver for HMM mm/hmm/test: add selftests for HMM MAINTAINERS: add HMM selftests
MAINTAINERS | 3 + include/uapi/linux/test_hmm.h | 59 ++
Isn't UAPI folder supposed to be for user-visible interfaces that follow the rule of non-breaking user space and not for selftests?
Thanks
Most of the other kernel module tests seem to invoke the test as part of the module load/init. I'm open to moving it if there is a more appropriate location.
Is it even possible to create a user mm_struct and put crazy things in it soley from a kernel module?
I didn't look very closely of what Ralph did in his patchsets, but from what I know, if you want in-kernel interface, you use in-kernel module, if you want to test user visible uapi, you write application. You don't create new UAPI just to test something in the kernel.
That works fine as long as the in-kernel interfaces don't require user created objects like mm_struct and vmas, which is the case here.
So there must be some special uAPI between the kerne/user to make it work.
Jason
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Here are some hunks I noticed while testing this:
--- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2201,7 +2201,8 @@ config TEST_MEMINIT
config TEST_HMM tristate "Test HMM (Heterogeneous Memory Management)" - depends on DEVICE_PRIVATE + depends on TRANSPARENT_HUGEPAGE + select DEVICE_PRIVATE select HMM_MIRROR select MMU_NOTIFIER help
It fails testing if TRANSPARENT_HUGEPAGE is not on
@@ -1097,6 +1071,7 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id) spin_lock_init(&mdevice->lock);
cdev_init(&mdevice->cdevice, &dmirror_fops); + mdevice->cdevice.owner = THIS_MODULE; ret = cdev_add(&mdevice->cdevice, dev, 1); if (ret) return ret;
The use of cdev without a struct device is super weird, but it still needs this
diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftests/vm/test_hmm.sh index 461e4a99a362cf..0647b525a62564 100755 --- a/tools/testing/selftests/vm/test_hmm.sh +++ b/tools/testing/selftests/vm/test_hmm.sh @@ -59,7 +59,7 @@ run_smoke() echo "Running smoke test. Note, this test provides basic coverage."
load_driver - ./hmm-tests + $(dirname "${BASH_SOURCE[0]}")/hmm-tests unload_driver }
Make it runnably reliably
Jason
On 4/15/20 7:41 AM, Jason Gunthorpe wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Here are some hunks I noticed while testing this:
--- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2201,7 +2201,8 @@ config TEST_MEMINIT config TEST_HMM tristate "Test HMM (Heterogeneous Memory Management)"
- depends on DEVICE_PRIVATE
- depends on TRANSPARENT_HUGEPAGE
- select DEVICE_PRIVATE select HMM_MIRROR select MMU_NOTIFIER help
It fails testing if TRANSPARENT_HUGEPAGE is not on
@@ -1097,6 +1071,7 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id) spin_lock_init(&mdevice->lock); cdev_init(&mdevice->cdevice, &dmirror_fops);
- mdevice->cdevice.owner = THIS_MODULE; ret = cdev_add(&mdevice->cdevice, dev, 1); if (ret) return ret;
The use of cdev without a struct device is super weird, but it still needs this
diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftests/vm/test_hmm.sh index 461e4a99a362cf..0647b525a62564 100755 --- a/tools/testing/selftests/vm/test_hmm.sh +++ b/tools/testing/selftests/vm/test_hmm.sh @@ -59,7 +59,7 @@ run_smoke() echo "Running smoke test. Note, this test provides basic coverage." load_driver
- ./hmm-tests
- $(dirname "${BASH_SOURCE[0]}")/hmm-tests unload_driver }
Make it runnably reliably
Jason
Thanks for the fixes. I'll apply these and send a v9. I will also add missing calls to release_mem_region() to free the reserved device private addresses.
On Wed, Apr 15, 2020 at 10:28:23AM -0700, Ralph Campbell wrote:
On 4/15/20 7:41 AM, Jason Gunthorpe wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Here are some hunks I noticed while testing this:
--- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2201,7 +2201,8 @@ config TEST_MEMINIT config TEST_HMM tristate "Test HMM (Heterogeneous Memory Management)"
- depends on DEVICE_PRIVATE
- depends on TRANSPARENT_HUGEPAGE
- select DEVICE_PRIVATE select HMM_MIRROR select MMU_NOTIFIER help
It fails testing if TRANSPARENT_HUGEPAGE is not on
@@ -1097,6 +1071,7 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id) spin_lock_init(&mdevice->lock); cdev_init(&mdevice->cdevice, &dmirror_fops);
- mdevice->cdevice.owner = THIS_MODULE; ret = cdev_add(&mdevice->cdevice, dev, 1); if (ret) return ret;
The use of cdev without a struct device is super weird, but it still needs this
diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftests/vm/test_hmm.sh index 461e4a99a362cf..0647b525a62564 100755 --- a/tools/testing/selftests/vm/test_hmm.sh +++ b/tools/testing/selftests/vm/test_hmm.sh @@ -59,7 +59,7 @@ run_smoke() echo "Running smoke test. Note, this test provides basic coverage." load_driver
- ./hmm-tests
- $(dirname "${BASH_SOURCE[0]}")/hmm-tests unload_driver }
Make it runnably reliably
Jason
Thanks for the fixes. I'll apply these and send a v9. I will also add missing calls to release_mem_region() to free the reserved device private addresses.
If you decide to ignore my request to avoid addition of special header file to UAPI, at least don't copy and install that file without some special CONFIG option (TEST_HMM ???) requested by the users. It also will be good to get Acked-by on this change from HMM people.
However, I still think that include/uapi/linux/test_hmm.h opens pandora box of having UAPI files without real promise to keep it backward compatible.
Thanks
On Wed, Apr 15, 2020 at 10:29:52PM +0300, Leon Romanovsky wrote:
On Wed, Apr 15, 2020 at 10:28:23AM -0700, Ralph Campbell wrote:
On 4/15/20 7:41 AM, Jason Gunthorpe wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Here are some hunks I noticed while testing this:
+++ b/lib/Kconfig.debug @@ -2201,7 +2201,8 @@ config TEST_MEMINIT config TEST_HMM tristate "Test HMM (Heterogeneous Memory Management)"
- depends on DEVICE_PRIVATE
- depends on TRANSPARENT_HUGEPAGE
- select DEVICE_PRIVATE select HMM_MIRROR select MMU_NOTIFIER help
It fails testing if TRANSPARENT_HUGEPAGE is not on
@@ -1097,6 +1071,7 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id) spin_lock_init(&mdevice->lock); cdev_init(&mdevice->cdevice, &dmirror_fops);
- mdevice->cdevice.owner = THIS_MODULE; ret = cdev_add(&mdevice->cdevice, dev, 1); if (ret) return ret;
The use of cdev without a struct device is super weird, but it still needs this
diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftests/vm/test_hmm.sh index 461e4a99a362cf..0647b525a62564 100755 +++ b/tools/testing/selftests/vm/test_hmm.sh @@ -59,7 +59,7 @@ run_smoke() echo "Running smoke test. Note, this test provides basic coverage." load_driver
- ./hmm-tests
- $(dirname "${BASH_SOURCE[0]}")/hmm-tests unload_driver }
Make it runnably reliably
Jason
Thanks for the fixes. I'll apply these and send a v9. I will also add missing calls to release_mem_region() to free the reserved device private addresses.
If you decide to ignore my request to avoid addition of special header file to UAPI, at least don't copy and install that file without some special CONFIG option (TEST_HMM ???) requested by the users. It also will be good to get Acked-by on this change from HMM people.
However, I still think that include/uapi/linux/test_hmm.h opens pandora box of having UAPI files without real promise to keep it backward compatible.
It would be nice if we could put the header outside the uapi directory and outside the install machinery
Maybe for now hackery some relative include like #include "../../../lib/hmm_test_uapi.h"
?
I don't see any sane way to avoid the dedicate module and special ioctl though.
Jason
On 4/15/20 12:29 PM, Leon Romanovsky wrote:
On Wed, Apr 15, 2020 at 10:28:23AM -0700, Ralph Campbell wrote:
On 4/15/20 7:41 AM, Jason Gunthorpe wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Here are some hunks I noticed while testing this:
--- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2201,7 +2201,8 @@ config TEST_MEMINIT config TEST_HMM tristate "Test HMM (Heterogeneous Memory Management)"
- depends on DEVICE_PRIVATE
- depends on TRANSPARENT_HUGEPAGE
- select DEVICE_PRIVATE select HMM_MIRROR select MMU_NOTIFIER help
It fails testing if TRANSPARENT_HUGEPAGE is not on
@@ -1097,6 +1071,7 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id) spin_lock_init(&mdevice->lock); cdev_init(&mdevice->cdevice, &dmirror_fops);
- mdevice->cdevice.owner = THIS_MODULE; ret = cdev_add(&mdevice->cdevice, dev, 1); if (ret) return ret;
The use of cdev without a struct device is super weird, but it still needs this
diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftests/vm/test_hmm.sh index 461e4a99a362cf..0647b525a62564 100755 --- a/tools/testing/selftests/vm/test_hmm.sh +++ b/tools/testing/selftests/vm/test_hmm.sh @@ -59,7 +59,7 @@ run_smoke() echo "Running smoke test. Note, this test provides basic coverage." load_driver
- ./hmm-tests
- $(dirname "${BASH_SOURCE[0]}")/hmm-tests unload_driver }
Make it runnably reliably
Jason
Thanks for the fixes. I'll apply these and send a v9. I will also add missing calls to release_mem_region() to free the reserved device private addresses.
If you decide to ignore my request to avoid addition of special header file to UAPI, at least don't copy and install that file without some special CONFIG option (TEST_HMM ???) requested by the users. It also will be good to get Acked-by on this change from HMM people.
However, I still think that include/uapi/linux/test_hmm.h opens pandora box of having UAPI files without real promise to keep it backward compatible.
Thanks
I think that is a valid point. I would expect the test<->driver UAPI to track the kernel version since the sources are "released" together. I suppose a version number could be included in the request structure to handle mismatch driver and test program but that may be overkill. Are you suggesting that include/linux/test_hmm.h is a better location?
On Wed, Apr 15, 2020 at 12:39:45PM -0700, Ralph Campbell wrote:
On 4/15/20 12:29 PM, Leon Romanovsky wrote:
On Wed, Apr 15, 2020 at 10:28:23AM -0700, Ralph Campbell wrote:
On 4/15/20 7:41 AM, Jason Gunthorpe wrote:
On Fri, Mar 20, 2020 at 05:31:05PM -0700, Ralph Campbell wrote:
This series adds basic self tests for HMM and are intended for Jason Gunthorpe's rdma tree which has a number of HMM patches applied.
Here are some hunks I noticed while testing this:
--- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2201,7 +2201,8 @@ config TEST_MEMINIT config TEST_HMM tristate "Test HMM (Heterogeneous Memory Management)"
- depends on DEVICE_PRIVATE
- depends on TRANSPARENT_HUGEPAGE
- select DEVICE_PRIVATE select HMM_MIRROR select MMU_NOTIFIER help
It fails testing if TRANSPARENT_HUGEPAGE is not on
@@ -1097,6 +1071,7 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id) spin_lock_init(&mdevice->lock); cdev_init(&mdevice->cdevice, &dmirror_fops);
- mdevice->cdevice.owner = THIS_MODULE; ret = cdev_add(&mdevice->cdevice, dev, 1); if (ret) return ret;
The use of cdev without a struct device is super weird, but it still needs this
diff --git a/tools/testing/selftests/vm/test_hmm.sh b/tools/testing/selftests/vm/test_hmm.sh index 461e4a99a362cf..0647b525a62564 100755 --- a/tools/testing/selftests/vm/test_hmm.sh +++ b/tools/testing/selftests/vm/test_hmm.sh @@ -59,7 +59,7 @@ run_smoke() echo "Running smoke test. Note, this test provides basic coverage." load_driver
- ./hmm-tests
- $(dirname "${BASH_SOURCE[0]}")/hmm-tests unload_driver }
Make it runnably reliably
Jason
Thanks for the fixes. I'll apply these and send a v9. I will also add missing calls to release_mem_region() to free the reserved device private addresses.
If you decide to ignore my request to avoid addition of special header file to UAPI, at least don't copy and install that file without some special CONFIG option (TEST_HMM ???) requested by the users. It also will be good to get Acked-by on this change from HMM people.
However, I still think that include/uapi/linux/test_hmm.h opens pandora box of having UAPI files without real promise to keep it backward compatible.
Thanks
I think that is a valid point. I would expect the test<->driver UAPI to track the kernel version since the sources are "released" together. I suppose a version number could be included in the request structure to handle mismatch driver and test program but that may be overkill.
Yes, it is really overkill.
Are you suggesting that include/linux/test_hmm.h is a better location?
It is one of options, another option maybe similar to that is done in scripts/mod/modpost.c [1], where C file is generated on the fly.
[1] https://lore.kernel.org/netdev/20200415133648.1306956-5-leon@kernel.org
linux-kselftest-mirror@lists.linaro.org
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Jason Gunthorpe -
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