From: jsg <jsg@openbsd.org>
Date: Thu, 12 Sep 2024 23:42:34 +0000 (+0000)
Subject: drm/amdgpu: reject gang submit on reserved VMIDs
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=742c464ec65e79fe4450ed256715306de4a73d0b;p=openbsd

drm/amdgpu: reject gang submit on reserved VMIDs

From Christian Koenig
6922ab2932622dbc638620aae0e2f6b8eb22940c in linux-6.6.y/6.6.51
320debca1ba3a81c87247eac84eff976ead09ee0 in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu_cs.c b/sys/dev/pci/drm/amd/amdgpu/amdgpu_cs.c
index f7bd2ba292e..dca5c07fa3b 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu_cs.c
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu_cs.c
@@ -1098,6 +1098,21 @@ static int amdgpu_cs_vm_handling(struct amdgpu_cs_parser *p)
 	unsigned int i;
 	int r;
 
+	/*
+	 * We can't use gang submit on with reserved VMIDs when the VM changes
+	 * can't be invalidated by more than one engine at the same time.
+	 */
+	if (p->gang_size > 1 && !p->adev->vm_manager.concurrent_flush) {
+		for (i = 0; i < p->gang_size; ++i) {
+			struct drm_sched_entity *entity = p->entities[i];
+			struct drm_gpu_scheduler *sched = entity->rq->sched;
+			struct amdgpu_ring *ring = to_amdgpu_ring(sched);
+
+			if (amdgpu_vmid_uses_reserved(vm, ring->vm_hub))
+				return -EINVAL;
+		}
+	}
+
 	r = amdgpu_vm_clear_freed(adev, vm, NULL);
 	if (r)
 		return r;
diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu_ids.c b/sys/dev/pci/drm/amd/amdgpu/amdgpu_ids.c
index 5b64d2a379f..27bdf32b0ed 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu_ids.c
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu_ids.c
@@ -409,7 +409,7 @@ int amdgpu_vmid_grab(struct amdgpu_vm *vm, struct amdgpu_ring *ring,
 	if (r || !idle)
 		goto error;
 
-	if (vm->reserved_vmid[vmhub] || (enforce_isolation && (vmhub == AMDGPU_GFXHUB(0)))) {
+	if (amdgpu_vmid_uses_reserved(vm, vmhub)) {
 		r = amdgpu_vmid_grab_reserved(vm, ring, job, &id, fence);
 		if (r || !id)
 			goto error;
@@ -459,6 +459,19 @@ error:
 	return r;
 }
 
+/*
+ * amdgpu_vmid_uses_reserved - check if a VM will use a reserved VMID
+ * @vm: the VM to check
+ * @vmhub: the VMHUB which will be used
+ *
+ * Returns: True if the VM will use a reserved VMID.
+ */
+bool amdgpu_vmid_uses_reserved(struct amdgpu_vm *vm, unsigned int vmhub)
+{
+	return vm->reserved_vmid[vmhub] ||
+		(enforce_isolation && (vmhub == AMDGPU_GFXHUB(0)));
+}
+
 int amdgpu_vmid_alloc_reserved(struct amdgpu_device *adev,
 			       unsigned vmhub)
 {
diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu_ids.h b/sys/dev/pci/drm/amd/amdgpu/amdgpu_ids.h
index 1aa1f81b772..3a5b2cc9a0e 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu_ids.h
+++ b/sys/dev/pci/drm/amd/amdgpu/amdgpu_ids.h
@@ -78,6 +78,7 @@ void amdgpu_pasid_free_delayed(struct dma_resv *resv,
 
 bool amdgpu_vmid_had_gpu_reset(struct amdgpu_device *adev,
 			       struct amdgpu_vmid *id);
+bool amdgpu_vmid_uses_reserved(struct amdgpu_vm *vm, unsigned int vmhub);
 int amdgpu_vmid_alloc_reserved(struct amdgpu_device *adev,
 				unsigned vmhub);
 void amdgpu_vmid_free_reserved(struct amdgpu_device *adev,