Device Coherent type uses device memory that is coherently accesible by the CPU. This could be shown as SP (special purpose) memory range at the BIOS-e820 memory enumeration. If no SP memory is supported in system, this could be faked by setting CONFIG_EFI_FAKE_MEMMAP.
Currently, test_hmm only supports two different SP ranges of at least 256MB size. This could be specified in the kernel parameter variable efi_fake_mem. Ex. Two SP ranges of 1GB starting at 0x100000000 & 0x140000000 physical address. Ex. efi_fake_mem=1G@0x100000000:0x40000,1G@0x140000000:0x40000
Private and coherent device mirror instances can be created in the same probed. This is done by passing the module parameters spm_addr_dev0 & spm_addr_dev1. In this case, it will create four instances of device_mirror. The first two correspond to private device type, the last two to coherent type. Then, they can be easily accessed from user space through /dev/hmm_mirror<num_device>. Usually num_device 0 and 1 are for private, and 2 and 3 for coherent types. If no module parameters are passed, two instances of private type device_mirror will be created only.
Signed-off-by: Alex Sierra alex.sierra@amd.com --- v4: Return number of coherent device pages successfully migrated to system. This is returned at cmd->cpages. --- lib/test_hmm.c | 260 +++++++++++++++++++++++++++++++++----------- lib/test_hmm_uapi.h | 15 ++- 2 files changed, 205 insertions(+), 70 deletions(-)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 6f068f7c4ee3..850d5331e370 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -29,11 +29,22 @@
#include "test_hmm_uapi.h"
-#define DMIRROR_NDEVICES 2 +#define DMIRROR_NDEVICES 4 #define DMIRROR_RANGE_FAULT_TIMEOUT 1000 #define DEVMEM_CHUNK_SIZE (256 * 1024 * 1024U) #define DEVMEM_CHUNKS_RESERVE 16
+/* + * For device_private pages, dpage is just a dummy struct page + * representing a piece of device memory. dmirror_devmem_alloc_page + * allocates a real system memory page as backing storage to fake a + * real device. zone_device_data points to that backing page. But + * for device_coherent memory, the struct page represents real + * physical CPU-accessible memory that we can use directly. + */ +#define BACKING_PAGE(page) (is_device_private_page((page)) ? \ + (page)->zone_device_data : (page)) + static unsigned long spm_addr_dev0; module_param(spm_addr_dev0, long, 0644); MODULE_PARM_DESC(spm_addr_dev0, @@ -122,6 +133,21 @@ static int dmirror_bounce_init(struct dmirror_bounce *bounce, return 0; }
+static bool dmirror_is_private_zone(struct dmirror_device *mdevice) +{ + return (mdevice->zone_device_type == + HMM_DMIRROR_MEMORY_DEVICE_PRIVATE) ? true : false; +} + +static enum migrate_vma_direction + dmirror_select_device(struct dmirror *dmirror) +{ + return (dmirror->mdevice->zone_device_type == + HMM_DMIRROR_MEMORY_DEVICE_PRIVATE) ? + MIGRATE_VMA_SELECT_DEVICE_PRIVATE : + MIGRATE_VMA_SELECT_DEVICE_COHERENT; +} + static void dmirror_bounce_fini(struct dmirror_bounce *bounce) { vfree(bounce->ptr); @@ -572,16 +598,19 @@ static int dmirror_allocate_chunk(struct dmirror_device *mdevice, static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice) { struct page *dpage = NULL; - struct page *rpage; + struct page *rpage = NULL;
/* - * This is a fake device so we alloc real system memory to store - * our device memory. + * For ZONE_DEVICE private type, this is a fake device so we alloc real + * system memory to store our device memory. + * For ZONE_DEVICE coherent type we use the actual dpage to store the data + * and ignore rpage. */ - rpage = alloc_page(GFP_HIGHUSER); - if (!rpage) - return NULL; - + if (dmirror_is_private_zone(mdevice)) { + rpage = alloc_page(GFP_HIGHUSER); + if (!rpage) + return NULL; + } spin_lock(&mdevice->lock);
if (mdevice->free_pages) { @@ -601,7 +630,8 @@ static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice) return dpage;
error: - __free_page(rpage); + if (rpage) + __free_page(rpage); return NULL; }
@@ -627,12 +657,16 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args, * unallocated pte_none() or read-only zero page. */ spage = migrate_pfn_to_page(*src); + if (WARN(spage && is_zone_device_page(spage), + "page already in device spage pfn: 0x%lx\n", + page_to_pfn(spage))) + continue;
dpage = dmirror_devmem_alloc_page(mdevice); if (!dpage) continue;
- rpage = dpage->zone_device_data; + rpage = BACKING_PAGE(dpage); if (spage) copy_highpage(rpage, spage); else @@ -646,6 +680,8 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args, */ rpage->zone_device_data = dmirror;
+ pr_debug("migrating from sys to dev pfn src: 0x%lx pfn dst: 0x%lx\n", + page_to_pfn(spage), page_to_pfn(dpage)); *dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; if ((*src & MIGRATE_PFN_WRITE) || @@ -724,11 +760,7 @@ static int dmirror_migrate_finalize_and_map(struct migrate_vma *args, 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; + entry = BACKING_PAGE(dpage); if (*dst & MIGRATE_PFN_WRITE) entry = xa_tag_pointer(entry, DPT_XA_TAG_WRITE); entry = xa_store(&dmirror->pt, pfn, entry, GFP_ATOMIC); @@ -808,15 +840,124 @@ static int dmirror_exclusive(struct dmirror *dmirror, return ret; }
-static int dmirror_migrate(struct dmirror *dmirror, - struct hmm_dmirror_cmd *cmd) +static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args, + struct dmirror *dmirror) +{ + 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; + + if (WARN_ON(!is_dev_private_or_coherent_page(spage))) + continue; + spage = BACKING_PAGE(spage); + dpage = alloc_page_vma(GFP_HIGHUSER_MOVABLE, args->vma, addr); + if (!dpage) + continue; + pr_debug("migrating from dev to sys pfn src: 0x%lx pfn dst: 0x%lx\n", + page_to_pfn(spage), page_to_pfn(dpage)); + + lock_page(dpage); + xa_erase(&dmirror->pt, addr >> PAGE_SHIFT); + copy_highpage(dpage, spage); + *dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; + if (*src & MIGRATE_PFN_WRITE) + *dst |= MIGRATE_PFN_WRITE; + } + return 0; +} + +static unsigned long dmirror_successful_migrated_pages(struct migrate_vma *migrate) +{ + unsigned long cpages = 0; + unsigned long i; + + for (i = 0; i < migrate->npages; i++) { + if (migrate->src[i] & MIGRATE_PFN_VALID && + migrate->src[i] & MIGRATE_PFN_MIGRATE) + cpages++; + } + return cpages; +} + +static int dmirror_migrate_to_system(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] = { 0 }; + unsigned long dst_pfns[64] = { 0 }; + 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; + + cmd->cpages = 0; + mmap_read_lock(mm); + for (addr = start; addr < end; addr = next) { + vma = vma_lookup(mm, addr); + if (!vma || !(vma->vm_flags & VM_READ)) { + 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.pgmap_owner = dmirror->mdevice; + args.flags = dmirror_select_device(dmirror); + + ret = migrate_vma_setup(&args); + if (ret) + goto out; + + pr_debug("Migrating from device mem to sys mem\n"); + dmirror_devmem_fault_alloc_and_copy(&args, dmirror); + + migrate_vma_pages(&args); + cmd->cpages += dmirror_successful_migrated_pages(&args); + migrate_vma_finalize(&args); + } +out: + mmap_read_unlock(mm); + mmput(mm); + + return ret; +} + +static int dmirror_migrate_to_device(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]; + unsigned long src_pfns[64] = { 0 }; + unsigned long dst_pfns[64] = { 0 }; struct dmirror_bounce bounce; struct migrate_vma args; unsigned long next; @@ -853,6 +994,7 @@ static int dmirror_migrate(struct dmirror *dmirror, if (ret) goto out;
+ pr_debug("Migrating from sys mem to device mem\n"); dmirror_migrate_alloc_and_copy(&args, dmirror); migrate_vma_pages(&args); dmirror_migrate_finalize_and_map(&args, dmirror); @@ -861,7 +1003,7 @@ static int dmirror_migrate(struct dmirror *dmirror, mmap_read_unlock(mm); mmput(mm);
- /* Return the migrated data for verification. */ + /* Return the migrated data for verification. only for pages in device zone */ ret = dmirror_bounce_init(&bounce, start, size); if (ret) return ret; @@ -898,12 +1040,22 @@ static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range, }
page = hmm_pfn_to_page(entry); - if (is_device_private_page(page)) { - /* Is the page migrated to this device or some other? */ - if (dmirror->mdevice == dmirror_page_to_device(page)) + if (is_dev_private_or_coherent_page(page)) { + /* Is page ZONE_DEVICE coherent? */ + if (is_device_coherent_page(page)) { + if (dmirror->mdevice == dmirror_page_to_device(page)) + *perm = HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL; + else + *perm = HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE; + /* + * Is page ZONE_DEVICE private migrated to + * this device or some other? + */ + } else if (dmirror->mdevice == dmirror_page_to_device(page)) { *perm = HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL; - else + } else { *perm = HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE; + } } else if (is_zero_pfn(page_to_pfn(page))) *perm = HMM_DMIRROR_PROT_ZERO; else @@ -1100,8 +1252,12 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp, ret = dmirror_write(dmirror, &cmd); break;
- case HMM_DMIRROR_MIGRATE: - ret = dmirror_migrate(dmirror, &cmd); + case HMM_DMIRROR_MIGRATE_TO_DEV: + ret = dmirror_migrate_to_device(dmirror, &cmd); + break; + + case HMM_DMIRROR_MIGRATE_TO_SYS: + ret = dmirror_migrate_to_system(dmirror, &cmd); break;
case HMM_DMIRROR_EXCLUSIVE: @@ -1142,14 +1298,13 @@ static const struct file_operations dmirror_fops = {
static void dmirror_devmem_free(struct page *page) { - struct page *rpage = page->zone_device_data; + struct page *rpage = BACKING_PAGE(page); struct dmirror_device *mdevice;
- if (rpage) + if (rpage != page) __free_page(rpage);
mdevice = dmirror_page_to_device(page); - spin_lock(&mdevice->lock); mdevice->cfree++; page->zone_device_data = mdevice->free_pages; @@ -1157,43 +1312,11 @@ static void dmirror_devmem_free(struct page *page) spin_unlock(&mdevice->lock); }
-static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args, - struct dmirror *dmirror) -{ - 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); - xa_erase(&dmirror->pt, addr >> PAGE_SHIFT); - copy_highpage(dpage, spage); - *dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; - if (*src & MIGRATE_PFN_WRITE) - *dst |= MIGRATE_PFN_WRITE; - } - return 0; -} - static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf) { struct migrate_vma args; - unsigned long src_pfns; - unsigned long dst_pfns; + unsigned long src_pfns = 0; + unsigned long dst_pfns = 0; struct page *rpage; struct dmirror *dmirror; vm_fault_t ret; @@ -1213,7 +1336,7 @@ static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf) args.src = &src_pfns; args.dst = &dst_pfns; args.pgmap_owner = dmirror->mdevice; - args.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE; + args.flags = dmirror_select_device(dmirror);
if (migrate_vma_setup(&args)) return VM_FAULT_SIGBUS; @@ -1292,6 +1415,12 @@ static int __init hmm_dmirror_init(void) HMM_DMIRROR_MEMORY_DEVICE_PRIVATE; dmirror_devices[ndevices++].zone_device_type = HMM_DMIRROR_MEMORY_DEVICE_PRIVATE; + if (spm_addr_dev0 && spm_addr_dev1) { + dmirror_devices[ndevices++].zone_device_type = + HMM_DMIRROR_MEMORY_DEVICE_COHERENT; + dmirror_devices[ndevices++].zone_device_type = + HMM_DMIRROR_MEMORY_DEVICE_COHERENT; + } for (id = 0; id < ndevices; id++) { ret = dmirror_device_init(dmirror_devices + id, id); if (ret) @@ -1314,7 +1443,8 @@ static void __exit hmm_dmirror_exit(void) int id;
for (id = 0; id < DMIRROR_NDEVICES; id++) - dmirror_device_remove(dmirror_devices + id); + if (dmirror_devices[id].zone_device_type) + dmirror_device_remove(dmirror_devices + id); unregister_chrdev_region(dmirror_dev, DMIRROR_NDEVICES); }
diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h index 625f3690d086..e190b2ab6f19 100644 --- a/lib/test_hmm_uapi.h +++ b/lib/test_hmm_uapi.h @@ -33,11 +33,12 @@ struct hmm_dmirror_cmd { /* Expose the address space of the calling process through hmm device file */ #define HMM_DMIRROR_READ _IOWR('H', 0x00, struct hmm_dmirror_cmd) #define HMM_DMIRROR_WRITE _IOWR('H', 0x01, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_MIGRATE _IOWR('H', 0x02, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x03, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x04, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd) -#define HMM_DMIRROR_GET_MEM_DEV_TYPE _IOWR('H', 0x06, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_MIGRATE_TO_DEV _IOWR('H', 0x02, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_MIGRATE_TO_SYS _IOWR('H', 0x03, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_SNAPSHOT _IOWR('H', 0x04, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_EXCLUSIVE _IOWR('H', 0x05, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_CHECK_EXCLUSIVE _IOWR('H', 0x06, struct hmm_dmirror_cmd) +#define HMM_DMIRROR_GET_MEM_DEV_TYPE _IOWR('H', 0x07, struct hmm_dmirror_cmd)
/* * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT. @@ -52,6 +53,8 @@ struct hmm_dmirror_cmd { * device the ioctl() is made * HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some * other device + * HMM_DMIRROR_PROT_DEV_COHERENT: Migrate device coherent page on the device + * the ioctl() is made */ enum { HMM_DMIRROR_PROT_ERROR = 0xFF, @@ -63,6 +66,8 @@ enum { HMM_DMIRROR_PROT_ZERO = 0x10, HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20, HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30, + HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL = 0x40, + HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE = 0x50, };
enum {