bianbu-repo-mirror/bianbu-linux-6.6
1
0
Fork 0
mirror of https://gitee.com/bianbu-linux/linux-6.6 synced 2025-04-24 14:07:52 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

drm/amdgpu: Add notifier lock for KFD userptrs

Browse source 
Add a per-process MMU notifier lock for processing notifiers from
userptrs. Use that lock to properly synchronize page table updates with
MMU notifiers.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Xiaogang Chen<Xiaogang.Chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Felix Kuehling 2021-04-21 21:09:54 -04:00 • committed by Alex Deucher
parent fe6872adb0
commit f95f51a4c3
6 changed files with 172 additions and 91 deletions
Download patch file Download diff file Expand all files Collapse all files

13
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
View file

@ -29,6 +29,7 @@
#include <linux/mm.h>
#include <linux/kthread.h>
#include <linux/workqueue.h>
#include <linux/mmu_notifier.h>
#include <kgd_kfd_interface.h>
#include <drm/ttm/ttm_execbuf_util.h>
#include "amdgpu_sync.h"
@ -65,6 +66,7 @@ struct kgd_mem {
struct mutex lock;
struct amdgpu_bo *bo;
struct dma_buf *dmabuf;
struct hmm_range *range;
struct list_head attachments;
/* protected by amdkfd_process_info.lock */
struct ttm_validate_buffer validate_list;
@ -75,7 +77,7 @@ struct kgd_mem {
uint32_t alloc_flags;
atomic_t invalid;
uint32_t invalid;
struct amdkfd_process_info *process_info;
struct amdgpu_sync sync;
@ -131,7 +133,8 @@ struct amdkfd_process_info {
struct amdgpu_amdkfd_fence *eviction_fence;
/* MMU-notifier related fields */
atomic_t evicted_bos;
struct mutex notifier_lock;
uint32_t evicted_bos;
struct delayed_work restore_userptr_work;
struct pid *pid;
bool block_mmu_notifications;
@ -180,7 +183,8 @@ int kfd_debugfs_kfd_mem_limits(struct seq_file *m, void *data);
bool amdkfd_fence_check_mm(struct dma_fence *f, struct mm_struct *mm);
struct amdgpu_amdkfd_fence *to_amdgpu_amdkfd_fence(struct dma_fence *f);
int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo);
int amdgpu_amdkfd_evict_userptr(struct kgd_mem *mem, struct mm_struct *mm);
int amdgpu_amdkfd_evict_userptr(struct mmu_interval_notifier *mni,
unsigned long cur_seq, struct kgd_mem *mem);
#else
static inline
bool amdkfd_fence_check_mm(struct dma_fence *f, struct mm_struct *mm)
@ -201,7 +205,8 @@ int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo)
}
static inline
int amdgpu_amdkfd_evict_userptr(struct kgd_mem *mem, struct mm_struct *mm)
int amdgpu_amdkfd_evict_userptr(struct mmu_interval_notifier *mni,
unsigned long cur_seq, struct kgd_mem *mem)
{
return 0;
}

212
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
View file

@ -964,7 +964,9 @@ static int init_user_pages(struct kgd_mem *mem, uint64_t user_addr,
* later stage when it is scheduled by another ioctl called by
* CRIU master process for the target pid for restore.
*/
atomic_inc(&mem->invalid);
mutex_lock(&process_info->notifier_lock);
mem->invalid++;
mutex_unlock(&process_info->notifier_lock);
mutex_unlock(&process_info->lock);
return 0;
}
@ -1301,6 +1303,7 @@ static int init_kfd_vm(struct amdgpu_vm *vm, void **process_info,
return -ENOMEM;
mutex_init(&info->lock);
mutex_init(&info->notifier_lock);
INIT_LIST_HEAD(&info->vm_list_head);
INIT_LIST_HEAD(&info->kfd_bo_list);
INIT_LIST_HEAD(&info->userptr_valid_list);
@ -1317,7 +1320,6 @@ static int init_kfd_vm(struct amdgpu_vm *vm, void **process_info,
}
info->pid = get_task_pid(current->group_leader, PIDTYPE_PID);
atomic_set(&info->evicted_bos, 0);
INIT_DELAYED_WORK(&info->restore_userptr_work,
amdgpu_amdkfd_restore_userptr_worker);
@ -1372,6 +1374,7 @@ reserve_pd_fail:
put_pid(info->pid);
create_evict_fence_fail:
mutex_destroy(&info->lock);
mutex_destroy(&info->notifier_lock);
kfree(info);
}
return ret;
@ -1496,6 +1499,7 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
cancel_delayed_work_sync(&process_info->restore_userptr_work);
put_pid(process_info->pid);
mutex_destroy(&process_info->lock);
mutex_destroy(&process_info->notifier_lock);
kfree(process_info);
}
}
@ -1548,7 +1552,9 @@ int amdgpu_amdkfd_criu_resume(void *p)
mutex_lock(&pinfo->lock);
pr_debug("scheduling work\n");
atomic_inc(&pinfo->evicted_bos);
mutex_lock(&pinfo->notifier_lock);
pinfo->evicted_bos++;
mutex_unlock(&pinfo->notifier_lock);
if (!READ_ONCE(pinfo->block_mmu_notifications)) {
ret = -EINVAL;
goto out_unlock;
@ -1773,8 +1779,13 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
list_del(&bo_list_entry->head);
mutex_unlock(&process_info->lock);
/* No more MMU notifiers */
amdgpu_hmm_unregister(mem->bo);
/* Cleanup user pages and MMU notifiers */
if (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm)) {
amdgpu_hmm_unregister(mem->bo);
mutex_lock(&process_info->notifier_lock);
amdgpu_ttm_tt_discard_user_pages(mem->bo->tbo.ttm, mem->range);
mutex_unlock(&process_info->notifier_lock);
}
ret = reserve_bo_and_cond_vms(mem, NULL, BO_VM_ALL, &ctx);
if (unlikely(ret))
@ -1864,6 +1875,16 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu(
*/
mutex_lock(&mem->process_info->lock);
/* Lock notifier lock. If we find an invalid userptr BO, we can be
* sure that the MMU notifier is no longer running
* concurrently and the queues are actually stopped
*/
if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm)) {
mutex_lock(&mem->process_info->notifier_lock);
is_invalid_userptr = !!mem->invalid;
mutex_unlock(&mem->process_info->notifier_lock);
}
mutex_lock(&mem->lock);
domain = mem->domain;
@ -2241,34 +2262,38 @@ int amdgpu_amdkfd_gpuvm_import_dmabuf(struct amdgpu_device *adev,
*
* Runs in MMU notifier, may be in RECLAIM_FS context. This means it
* cannot do any memory allocations, and cannot take any locks that
* are held elsewhere while allocating memory. Therefore this is as
* simple as possible, using atomic counters.
* are held elsewhere while allocating memory.
*
* It doesn't do anything to the BO itself. The real work happens in
* restore, where we get updated page addresses. This function only
* ensures that GPU access to the BO is stopped.
*/
int amdgpu_amdkfd_evict_userptr(struct kgd_mem *mem,
struct mm_struct *mm)
int amdgpu_amdkfd_evict_userptr(struct mmu_interval_notifier *mni,
unsigned long cur_seq, struct kgd_mem *mem)
{
struct amdkfd_process_info *process_info = mem->process_info;
int evicted_bos;
int r = 0;
/* Do not process MMU notifications until stage-4 IOCTL is received */
/* Do not process MMU notifications during CRIU restore until
* KFD_CRIU_OP_RESUME IOCTL is received
*/
if (READ_ONCE(process_info->block_mmu_notifications))
return 0;
atomic_inc(&mem->invalid);
evicted_bos = atomic_inc_return(&process_info->evicted_bos);
if (evicted_bos == 1) {
mutex_lock(&process_info->notifier_lock);
mmu_interval_set_seq(mni, cur_seq);
mem->invalid++;
if (++process_info->evicted_bos == 1) {
/* First eviction, stop the queues */
r = kgd2kfd_quiesce_mm(mm, KFD_QUEUE_EVICTION_TRIGGER_USERPTR);
r = kgd2kfd_quiesce_mm(mni->mm,
KFD_QUEUE_EVICTION_TRIGGER_USERPTR);
if (r)
pr_err("Failed to quiesce KFD\n");
schedule_delayed_work(&process_info->restore_userptr_work,
msecs_to_jiffies(AMDGPU_USERPTR_RESTORE_DELAY_MS));
}
mutex_unlock(&process_info->notifier_lock);
return r;
}
@ -2285,54 +2310,58 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info,
struct kgd_mem *mem, *tmp_mem;
struct amdgpu_bo *bo;
struct ttm_operation_ctx ctx = { false, false };
int invalid, ret;
uint32_t invalid;
int ret = 0;
/* Move all invalidated BOs to the userptr_inval_list and
* release their user pages by migration to the CPU domain
*/
mutex_lock(&process_info->notifier_lock);
/* Move all invalidated BOs to the userptr_inval_list */
list_for_each_entry_safe(mem, tmp_mem,
&process_info->userptr_valid_list,
validate_list.head) {
if (!atomic_read(&mem->invalid))
continue; /* BO is still valid */
bo = mem->bo;
if (amdgpu_bo_reserve(bo, true))
return -EAGAIN;
amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU);
ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
amdgpu_bo_unreserve(bo);
if (ret) {
pr_err("%s: Failed to invalidate userptr BO\n",
__func__);
return -EAGAIN;
}
list_move_tail(&mem->validate_list.head,
&process_info->userptr_inval_list);
}
if (list_empty(&process_info->userptr_inval_list))
return 0; /* All evicted userptr BOs were freed */
validate_list.head)
if (mem->invalid)
list_move_tail(&mem->validate_list.head,
&process_info->userptr_inval_list);
/* Go through userptr_inval_list and update any invalid user_pages */
list_for_each_entry(mem, &process_info->userptr_inval_list,
validate_list.head) {
struct hmm_range *range;
invalid = atomic_read(&mem->invalid);
invalid = mem->invalid;
if (!invalid)
/* BO hasn't been invalidated since the last
* revalidation attempt. Keep its BO list.
* revalidation attempt. Keep its page list.
*/
continue;
bo = mem->bo;
amdgpu_ttm_tt_discard_user_pages(bo->tbo.ttm, mem->range);
mem->range = NULL;
/* BO reservations and getting user pages (hmm_range_fault)
* must happen outside the notifier lock
*/
mutex_unlock(&process_info->notifier_lock);
/* Move the BO to system (CPU) domain if necessary to unmap
* and free the SG table
*/
if (bo->tbo.resource->mem_type != TTM_PL_SYSTEM) {
if (amdgpu_bo_reserve(bo, true))
return -EAGAIN;
amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU);
ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
amdgpu_bo_unreserve(bo);
if (ret) {
pr_err("%s: Failed to invalidate userptr BO\n",
__func__);
return -EAGAIN;
}
}
/* Get updated user pages */
ret = amdgpu_ttm_tt_get_user_pages(bo, bo->tbo.ttm->pages,
&range);
&mem->range);
if (ret) {
pr_debug("Failed %d to get user pages\n", ret);
@ -2345,30 +2374,32 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info,
*/
if (ret != -EFAULT)
return ret;
} else {
/*
* FIXME: Cannot ignore the return code, must hold
* notifier_lock
*/
amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm, range);
ret = 0;
}
mutex_lock(&process_info->notifier_lock);
/* Mark the BO as valid unless it was invalidated
* again concurrently.
*/
if (atomic_cmpxchg(&mem->invalid, invalid, 0) != invalid)
return -EAGAIN;
if (mem->invalid != invalid) {
ret = -EAGAIN;
goto unlock_out;
}
mem->invalid = 0;
}
return 0;
unlock_out:
mutex_unlock(&process_info->notifier_lock);
return ret;
}
/* Validate invalid userptr BOs
*
* Validates BOs on the userptr_inval_list, and moves them back to the
* userptr_valid_list. Also updates GPUVM page tables with new page
* addresses and waits for the page table updates to complete.
* Validates BOs on the userptr_inval_list. Also updates GPUVM page tables
* with new page addresses and waits for the page table updates to complete.
*/
static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
{
@ -2439,9 +2470,6 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
}
}
list_move_tail(&mem->validate_list.head,
&process_info->userptr_valid_list);
/* Update mapping. If the BO was not validated
* (because we couldn't get user pages), this will
* clear the page table entries, which will result in
@ -2457,7 +2485,9 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
if (ret) {
pr_err("%s: update PTE failed\n", __func__);
/* make sure this gets validated again */
atomic_inc(&mem->invalid);
mutex_lock(&process_info->notifier_lock);
mem->invalid++;
mutex_unlock(&process_info->notifier_lock);
goto unreserve_out;
}
}
@ -2477,6 +2507,36 @@ out_no_mem:
return ret;
}
/* Confirm that all user pages are valid while holding the notifier lock
*
* Moves valid BOs from the userptr_inval_list back to userptr_val_list.
*/
static int confirm_valid_user_pages_locked(struct amdkfd_process_info *process_info)
{
struct kgd_mem *mem, *tmp_mem;
int ret = 0;
list_for_each_entry_safe(mem, tmp_mem,
&process_info->userptr_inval_list,
validate_list.head) {
bool valid = amdgpu_ttm_tt_get_user_pages_done(
mem->bo->tbo.ttm, mem->range);
mem->range = NULL;
if (!valid) {
WARN(!mem->invalid, "Invalid BO not marked invalid");
ret = -EAGAIN;
continue;
}
WARN(mem->invalid, "Valid BO is marked invalid");
list_move_tail(&mem->validate_list.head,
&process_info->userptr_valid_list);
}
return ret;
}
/* Worker callback to restore evicted userptr BOs
*
* Tries to update and validate all userptr BOs. If successful and no
@ -2491,9 +2551,11 @@ static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work)
restore_userptr_work);
struct task_struct *usertask;
struct mm_struct *mm;
int evicted_bos;
uint32_t evicted_bos;
evicted_bos = atomic_read(&process_info->evicted_bos);
mutex_lock(&process_info->notifier_lock);
evicted_bos = process_info->evicted_bos;
mutex_unlock(&process_info->notifier_lock);
if (!evicted_bos)
return;
@ -2516,9 +2578,6 @@ static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work)
* and we can just restart the queues.
*/
if (!list_empty(&process_info->userptr_inval_list)) {
if (atomic_read(&process_info->evicted_bos) != evicted_bos)
goto unlock_out; /* Concurrent eviction, try again */
if (validate_invalid_user_pages(process_info))
goto unlock_out;
}
@ -2527,10 +2586,17 @@ static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work)
* be a first eviction that calls quiesce_mm. The eviction
* reference counting inside KFD will handle this case.
*/
if (atomic_cmpxchg(&process_info->evicted_bos, evicted_bos, 0) !=
evicted_bos)
goto unlock_out;
evicted_bos = 0;
mutex_lock(&process_info->notifier_lock);
if (process_info->evicted_bos != evicted_bos)
goto unlock_notifier_out;
if (confirm_valid_user_pages_locked(process_info)) {
WARN(1, "User pages unexpectedly invalid");
goto unlock_notifier_out;
}
process_info->evicted_bos = evicted_bos = 0;
if (kgd2kfd_resume_mm(mm)) {
pr_err("%s: Failed to resume KFD\n", __func__);
/* No recovery from this failure. Probably the CP is
@ -2538,6 +2604,8 @@ static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work)
*/
}
unlock_notifier_out:
mutex_unlock(&process_info->notifier_lock);
unlock_out:
mutex_unlock(&process_info->lock);

12
drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c
View file

@ -105,17 +105,11 @@ static bool amdgpu_hmm_invalidate_hsa(struct mmu_interval_notifier *mni,
unsigned long cur_seq)
{
struct amdgpu_bo *bo = container_of(mni, struct amdgpu_bo, notifier);
struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
if (!mmu_notifier_range_blockable(range))
return false;
mutex_lock(&adev->notifier_lock);
mmu_interval_set_seq(mni, cur_seq);
amdgpu_amdkfd_evict_userptr(bo->kfd_bo, bo->notifier.mm);
mutex_unlock(&adev->notifier_lock);
amdgpu_amdkfd_evict_userptr(mni, cur_seq, bo->kfd_bo);
return true;
}
@ -244,9 +238,9 @@ out_free_range:
return r;
}
int amdgpu_hmm_range_get_pages_done(struct hmm_range *hmm_range)
bool amdgpu_hmm_range_get_pages_done(struct hmm_range *hmm_range)
{
int r;
bool r;
r = mmu_interval_read_retry(hmm_range->notifier,
hmm_range->notifier_seq);

3
drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.h
View file

@ -29,12 +29,13 @@
#include <linux/rwsem.h>
#include <linux/workqueue.h>
#include <linux/interval_tree.h>
#include <linux/mmu_notifier.h>
int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier,
uint64_t start, uint64_t npages, bool readonly,
void *owner, struct page **pages,
struct hmm_range **phmm_range);
int amdgpu_hmm_range_get_pages_done(struct hmm_range *hmm_range);
bool amdgpu_hmm_range_get_pages_done(struct hmm_range *hmm_range);
#if defined(CONFIG_HMM_MIRROR)
int amdgpu_hmm_register(struct amdgpu_bo *bo, unsigned long addr);

17
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
View file

@ -695,8 +695,19 @@ out_unlock:
return r;
}
/* amdgpu_ttm_tt_discard_user_pages - Discard range and pfn array allocations
*/
void amdgpu_ttm_tt_discard_user_pages(struct ttm_tt *ttm,
struct hmm_range *range)
{
struct amdgpu_ttm_tt *gtt = (void *)ttm;
if (gtt && gtt->userptr && range)
amdgpu_hmm_range_get_pages_done(range);
}
/*
* amdgpu_ttm_tt_userptr_range_done - stop HMM track the CPU page table change
* amdgpu_ttm_tt_get_user_pages_done - stop HMM track the CPU page table change
* Check if the pages backing this ttm range have been invalidated
*
* Returns: true if pages are still valid
@ -714,10 +725,6 @@ bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm,
WARN_ONCE(!range->hmm_pfns, "No user pages to check\n");
/*
* FIXME: Must always hold notifier_lock for this, and must
* not ignore the return code.
*/
return !amdgpu_hmm_range_get_pages_done(range);
}
#endif

6
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
View file

@ -159,6 +159,8 @@ uint64_t amdgpu_ttm_domain_start(struct amdgpu_device *adev, uint32_t type);
#if IS_ENABLED(CONFIG_DRM_AMDGPU_USERPTR)
int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo, struct page **pages,
struct hmm_range **range);
void amdgpu_ttm_tt_discard_user_pages(struct ttm_tt *ttm,
struct hmm_range *range);
bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm,
struct hmm_range *range);
#else
@ -168,6 +170,10 @@ static inline int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo,
{
return -EPERM;
}
static inline void amdgpu_ttm_tt_discard_user_pages(struct ttm_tt *ttm,
struct hmm_range *range)
{
}
static inline bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm,
struct hmm_range *range)
{