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drm/amdkfd: validate svm range system memory

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Use HMM to get system memory pages address, which will be used to
map to GPUs or migrate to vram.

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Philip Yang 2020-02-15 15:02:49 -05:00 committed by Alex Deucher
parent d8a3c1c80c
commit b1c46c7d62
2 changed files with 133 additions and 1 deletions
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116
drivers/gpu/drm/amd/amdkfd/kfd_svm.c
View File

@ -29,6 +29,15 @@
#include "kfd_priv.h"
#include "kfd_svm.h"
static bool
svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
const struct mmu_notifier_range *range,
unsigned long cur_seq);
static const struct mmu_interval_notifier_ops svm_range_mn_ops = {
.invalidate = svm_range_cpu_invalidate_pagetables,
};
/**
* svm_range_unlink - unlink svm_range from lists and interval tree
* @prange: svm range structure to be removed
@ -47,6 +56,18 @@ static void svm_range_unlink(struct svm_range *prange)
interval_tree_remove(&prange->it_node, &prange->svms->objects);
}
static void
svm_range_add_notifier_locked(struct mm_struct *mm, struct svm_range *prange)
{
pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
prange, prange->start, prange->last);
mmu_interval_notifier_insert_locked(&prange->notifier, mm,
prange->start << PAGE_SHIFT,
prange->npages << PAGE_SHIFT,
&svm_range_mn_ops);
}
/**
* svm_range_add_to_svms - add svm range to svms
* @prange: svm range structure to be added
@ -66,11 +87,24 @@ static void svm_range_add_to_svms(struct svm_range *prange)
interval_tree_insert(&prange->it_node, &prange->svms->objects);
}
static void svm_range_remove_notifier(struct svm_range *prange)
{
pr_debug("remove notifier svms 0x%p prange 0x%p [0x%lx 0x%lx]\n",
prange->svms, prange,
prange->notifier.interval_tree.start >> PAGE_SHIFT,
prange->notifier.interval_tree.last >> PAGE_SHIFT);
if (prange->notifier.interval_tree.start != 0 &&
prange->notifier.interval_tree.last != 0)
mmu_interval_notifier_remove(&prange->notifier);
}
static void svm_range_free(struct svm_range *prange)
{
pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms, prange,
prange->start, prange->last);
mutex_destroy(&prange->lock);
kfree(prange);
}
@ -103,6 +137,7 @@ svm_range *svm_range_new(struct svm_range_list *svms, uint64_t start,
INIT_LIST_HEAD(&prange->update_list);
INIT_LIST_HEAD(&prange->remove_list);
INIT_LIST_HEAD(&prange->insert_list);
mutex_init(&prange->lock);
svm_range_set_default_attributes(&prange->preferred_loc,
&prange->prefetch_loc,
&prange->granularity, &prange->flags);
@ -376,6 +411,65 @@ svm_range_split_head(struct svm_range *prange, struct svm_range *new,
return r;
}
/*
* Validation+GPU mapping with concurrent invalidation (MMU notifiers)
*
* To prevent concurrent destruction or change of range attributes, the
* svm_read_lock must be held. The caller must not hold the svm_write_lock
* because that would block concurrent evictions and lead to deadlocks. To
* serialize concurrent migrations or validations of the same range, the
* prange->migrate_mutex must be held.
*
* For VRAM ranges, the SVM BO must be allocated and valid (protected by its
* eviction fence.
*
* The following sequence ensures race-free validation and GPU mapping:
*
* 1. Reserve page table (and SVM BO if range is in VRAM)
* 2. hmm_range_fault to get page addresses (if system memory)
* 3. DMA-map pages (if system memory)
* 4-a. Take notifier lock
* 4-b. Check that pages still valid (mmu_interval_read_retry)
* 4-c. Check that the range was not split or otherwise invalidated
* 4-d. Update GPU page table
* 4.e. Release notifier lock
* 5. Release page table (and SVM BO) reservation
*/
static int svm_range_validate_and_map(struct mm_struct *mm,
struct svm_range *prange,
uint32_t gpuidx, bool intr, bool wait)
{
struct hmm_range *hmm_range;
int r = 0;
if (!prange->actual_loc) {
r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL,
prange->start << PAGE_SHIFT,
prange->npages, &hmm_range,
false, true);
if (r) {
pr_debug("failed %d to get svm range pages\n", r);
goto unreserve_out;
}
}
svm_range_lock(prange);
if (!prange->actual_loc) {
if (amdgpu_hmm_range_get_pages_done(hmm_range)) {
r = -EAGAIN;
goto unlock_out;
}
}
/* TODO: map to GPU */
unlock_out:
svm_range_unlock(prange);
unreserve_out:
return r;
}
static struct svm_range *svm_range_clone(struct svm_range *old)
{
struct svm_range *new;
@ -516,6 +610,18 @@ out:
return r;
}
/**
* svm_range_cpu_invalidate_pagetables - interval notifier callback
*
*/
static bool
svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
const struct mmu_notifier_range *range,
unsigned long cur_seq)
{
return true;
}
void svm_range_list_fini(struct kfd_process *p)
{
mutex_destroy(&p->svms.lock);
@ -669,6 +775,7 @@ svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,
/* Apply changes as a transaction */
list_for_each_entry_safe(prange, next, &insert_list, insert_list) {
svm_range_add_to_svms(prange);
svm_range_add_notifier_locked(mm, prange);
}
list_for_each_entry(prange, &update_list, update_list) {
svm_range_apply_attrs(p, prange, nattr, attrs);
@ -680,6 +787,7 @@ svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,
prange->svms, prange, prange->start,
prange->last);
svm_range_unlink(prange);
svm_range_remove_notifier(prange);
svm_range_free(prange);
}
@ -690,7 +798,13 @@ svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,
* case because the rollback wouldn't be guaranteed to work either.
*/
list_for_each_entry(prange, &update_list, update_list) {
/* TODO */
r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
true, true);
if (r) {
pr_debug("failed %d to map 0x%lx to gpus\n", r,
prange->start);
break;
}
}
svm_range_debug_dump(svms);

18
drivers/gpu/drm/amd/amdkfd/kfd_svm.h
View File

@ -46,11 +46,14 @@
* @remove_list:link list node used to add to remove list
* @insert_list:link list node used to add to insert list
* @npages: number of pages
* @lock: protect prange start, last, child_list, svm_bo_list
* @saved_flags:save/restore current PF_MEMALLOC flags
* @flags: flags defined as KFD_IOCTL_SVM_FLAG_*
* @perferred_loc: perferred location, 0 for CPU, or GPU id
* @perfetch_loc: last prefetch location, 0 for CPU, or GPU id
* @actual_loc: the actual location, 0 for CPU, or GPU id
* @granularity:migration granularity, log2 num pages
* @notifier: register mmu interval notifier
* @bitmap_access: index bitmap of GPUs which can access the range
* @bitmap_aip: index bitmap of GPUs which can access the range in place
*
@ -68,15 +71,30 @@ struct svm_range {
struct list_head remove_list;
struct list_head insert_list;
uint64_t npages;
struct mutex lock;
unsigned int saved_flags;
uint32_t flags;
uint32_t preferred_loc;
uint32_t prefetch_loc;
uint32_t actual_loc;
uint8_t granularity;
struct mmu_interval_notifier notifier;
DECLARE_BITMAP(bitmap_access, MAX_GPU_INSTANCE);
DECLARE_BITMAP(bitmap_aip, MAX_GPU_INSTANCE);
};
static inline void svm_range_lock(struct svm_range *prange)
{
mutex_lock(&prange->lock);
prange->saved_flags = memalloc_noreclaim_save();
}
static inline void svm_range_unlock(struct svm_range *prange)
{
memalloc_noreclaim_restore(prange->saved_flags);
mutex_unlock(&prange->lock);
}
int svm_range_list_init(struct kfd_process *p);
void svm_range_list_fini(struct kfd_process *p);
int svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,