From a057ff640caa69c30741252a3bf18052891eb75f Mon Sep 17 00:00:00 2001
From: Philip Yang <Philip.Yang@amd.com>
Date: Tue, 5 Apr 2022 22:24:42 -0400
Subject: drm/amdkfd: Handle drain retry fault race with XNACK mode change
Git-commit: edd11922e3d01549fc6f5a1fa1413eb2f7d5be55
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Application could change XNACK enabled to disabled while KFD is draining
stale retry fault, therefore the check for whether to drain retry faults
must be before the check for whether xnack_enabled, to avoid report
incorrect vm fault after application changes XNACK mode.

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 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 c5405ec948e3..45187928520d 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2685,11 +2685,6 @@ 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);
@@ -2700,6 +2695,12 @@ 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.
 	 */
-- 
2.38.1