Re: [PATCH 1/1] drm/amdkfd: Handle drain retry fault race with XNACK mode change

[Felix Kuehling]

Am 2022-04-07 um 21:21 schrieb Philip Yang:
Application could change XNACK enabled to disabled while KFD is draining
stall retry fault, the check for whether to drain retry faults must be

typo: stall -> stale

I think there is also a word missing, linking the two sentences. Maybe 
"... stale retry faults, therefore the check ..."  With that fixed, the 
patch is

Reviewed-by: Felix Kuehling <felix.kuehl...@amd.com>


before the check for whether xnack_enabled, to avoid report incorrect vm
fault after application changes XNACK mode.

Signed-off-by: Philip Yang <philip.y...@amd.com>
---
  drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 11 ++++++-----
  1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index d011d620dfe7..c76d29a22e9d 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2700,11 +2700,6 @@ svm_range_restore_pages(struct amdgpu_device *adev, 
unsigned int pasid,
                pr_debug("kfd process not founded pasid 0x%x\n", pasid);
                return 0;
        }
-       if (!p->xnack_enabled) {
-               pr_debug("XNACK not enabled for pasid 0x%x\n", pasid);
-               r = -EFAULT;
-               goto out;
-       }
        svms = &p->svms;
  
  	pr_debug("restoring svms 0x%p fault address 0x%llx\n", svms, addr);
@@ -2715,6 +2710,12 @@ svm_range_restore_pages(struct amdgpu_device *adev, 
unsigned int pasid,
                goto out;
        }
  
+	if (!p->xnack_enabled) {
+               pr_debug("XNACK not enabled for pasid 0x%x\n", pasid);
+               r = -EFAULT;
+               goto out;
+       }
+
        /* p->lead_thread is available as kfd_process_wq_release flush the work
         * before releasing task ref.
         */