[20/44] drm/amdkfd: invalidate tables on page retry fault

Commit Message

Felix Kuehling March 22, 2021, 10:58 a.m. UTC

GPU page tables are invalidated by unmapping prange directly at
the mmu notifier, when page fault retry is enabled through
amdgpu_noretry global parameter. The restore page table is
performed at the page fault handler.

If xnack is on, we update GPU mappings after migration to avoid
unnecessary GPUVM faults.

Signed-off-by: Alex Sierra <[e-mail]>
Signed-off-by: Philip Yang <[e-mail]>
Signed-off-by: Felix Kuehling <[e-mail]>
---
 drivers/gpu/drm/amd/amdkfd/kfd_migrate.c |  6 +-
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c     | 71 +++++++++++++++++++-----
 drivers/gpu/drm/amd/amdkfd/kfd_svm.h     |  4 +-
 3 files changed, 64 insertions(+), 17 deletions(-)

Patch

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
index 1243cf02f872..8ce3ff56a0ce 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c
@@ -789,7 +789,11 @@  static vm_fault_t svm_migrate_to_ram(struct vm_fault *vmf)
 	list_for_each_entry_safe(prange, next, &update_list, update_list) {
 		enum svm_work_list_ops op;
 
-		op = SVM_OP_UPDATE_RANGE_NOTIFIER;
+		/* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
+		if (p->xnack_enabled && prange == pmigrate)
+			op = SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP;
+		else
+			op = SVM_OP_UPDATE_RANGE_NOTIFIER;
 
 		svm_range_add_list_work(&p->svms, prange, mm, op);
 		list_del_init(&prange->update_list);
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 69241ed4a377..fb8ca844d9bd 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1006,6 +1006,13 @@  svm_range_split_by_granularity(struct kfd_process *p, struct mm_struct *mm,
 
 	*pmigrate = new;
 
+	/* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
+	if (p->xnack_enabled && (*pmigrate)->work_item.op == SVM_OP_ADD_RANGE) {
+		(*pmigrate)->work_item.op = SVM_OP_ADD_RANGE_AND_MAP;
+		pr_debug("change prange 0x%p [0x%lx 0x%lx] op %d\n",
+			 *pmigrate, (*pmigrate)->start, (*pmigrate)->last,
+			 SVM_OP_ADD_RANGE_AND_MAP);
+	}
 	return 0;
 }
 
@@ -1407,25 +1414,38 @@  svm_range_evict(struct svm_range *prange, struct mm_struct *mm,
 		unsigned long start, unsigned long last)
 {
 	struct svm_range_list *svms = prange->svms;
-	int invalid, evicted_ranges;
+	struct kfd_process *p;
 	int r = 0;
 
-	invalid = atomic_inc_return(&prange->invalid);
-	evicted_ranges = atomic_inc_return(&svms->evicted_ranges);
-	if (evicted_ranges != 1)
-		return r;
+	p = container_of(svms, struct kfd_process, svms);
 
-	pr_debug("evicting svms 0x%p range [0x%lx 0x%lx]\n",
-		 prange->svms, prange->start, prange->last);
+	pr_debug("invalidate svms 0x%p prange [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
+		 svms, prange->start, prange->last, start, last);
 
-	/* First eviction, stop the queues */
-	r = kgd2kfd_quiesce_mm(mm);
-	if (r)
-		pr_debug("failed to quiesce KFD\n");
+	if (!p->xnack_enabled) {
+		int invalid, evicted_ranges;
+
+		invalid = atomic_inc_return(&prange->invalid);
+		evicted_ranges = atomic_inc_return(&svms->evicted_ranges);
+		if (evicted_ranges != 1)
+			return r;
 
-	pr_debug("schedule to restore svm %p ranges\n", svms);
-	schedule_delayed_work(&svms->restore_work,
-		msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
+		pr_debug("evicting svms 0x%p range [0x%lx 0x%lx]\n",
+			 prange->svms, prange->start, prange->last);
+
+		/* First eviction, stop the queues */
+		r = kgd2kfd_quiesce_mm(mm);
+		if (r)
+			pr_debug("failed to quiesce KFD\n");
+
+		pr_debug("schedule to restore svm %p ranges\n", svms);
+		schedule_delayed_work(&svms->restore_work,
+			msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
+	} else {
+		pr_debug("invalidate unmap svms 0x%p [0x%lx 0x%lx] from GPUs\n",
+			 prange->svms, start, last);
+		svm_range_unmap_from_gpus(prange, start, last);
+	}
 
 	return r;
 }
@@ -1621,6 +1641,7 @@  static void
 svm_range_handle_list_op(struct svm_range_list *svms, struct svm_range *prange)
 {
 	struct mm_struct *mm = prange->work_item.mm;
+	int r;
 
 	switch (prange->work_item.op) {
 	case SVM_OP_NULL:
@@ -1639,12 +1660,32 @@  svm_range_handle_list_op(struct svm_range_list *svms, struct svm_range *prange)
 			 svms, prange, prange->start, prange->last);
 		svm_range_update_notifier_and_interval_tree(mm, prange);
 		break;
+	case SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP:
+		pr_debug("update and map 0x%p prange 0x%p [0x%lx 0x%lx]\n",
+			 svms, prange, prange->start, prange->last);
+		svm_range_update_notifier_and_interval_tree(mm, prange);
+
+		r = svm_range_map_to_gpus(prange, true);
+		if (r)
+			pr_debug("failed %d map 0x%p [0x%lx 0x%lx]\n",
+				 r, svms, prange->start, prange->last);
+		break;
 	case SVM_OP_ADD_RANGE:
 		pr_debug("add 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms, prange,
 			 prange->start, prange->last);
 		svm_range_add_to_svms(prange);
 		svm_range_add_notifier_locked(mm, prange);
 		break;
+	case SVM_OP_ADD_RANGE_AND_MAP:
+		pr_debug("add and map 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms,
+			 prange, prange->start, prange->last);
+		svm_range_add_to_svms(prange);
+		svm_range_add_notifier_locked(mm, prange);
+		r = svm_range_map_to_gpus(prange, true);
+		if (r)
+			pr_debug("failed %d map 0x%p [0x%lx 0x%lx]\n",
+				 r, svms, prange->start, prange->last);
+		break;
 	default:
 		WARN_ONCE(1, "Unknown prange 0x%p work op %d\n", prange,
 			 prange->work_item.op);
@@ -2235,7 +2276,7 @@  svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,
 		if (r)
 			goto out_unlock_range;
 
-		if (migrated) {
+		if (migrated && !p->xnack_enabled) {
 			pr_debug("restore_work will update mappings of GPUs\n");
 			mutex_unlock(&prange->migrate_mutex);
 			continue;
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.h b/drivers/gpu/drm/amd/amdkfd/kfd_svm.h
index e6b737889bb3..3f945a601546 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.h
@@ -43,7 +43,9 @@  enum svm_work_list_ops {
 	SVM_OP_NULL,
 	SVM_OP_UNMAP_RANGE,
 	SVM_OP_UPDATE_RANGE_NOTIFIER,
-	SVM_OP_ADD_RANGE
+	SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP,
+	SVM_OP_ADD_RANGE,
+	SVM_OP_ADD_RANGE_AND_MAP
 };
 
 struct svm_work_list_item {