[PATCH] drm/amdgpu/virt: skip VM fault handler for VF

[Pixel Ding]

VF uses KIQ to access registers. When VM fault occurs, the driver
can't get back the fence of KIQ submission and runs into CPU soft
lockup.

Signed-off-by: Pixel Ding <Pixel.Ding at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
index 7669b32..ff4fb37 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
@@ -1237,6 +1237,11 @@ static int gmc_v8_0_process_interrupt(struct amdgpu_device *adev,
 {
 	u32 addr, status, mc_client;
 
+	if (amdgpu_sriov_vf(adev)) {
+		dev_err(adev->dev, "GPU fault detected on VF, can't access VM registers\n");
+		return 0;
+	}
+
 	addr = RREG32(mmVM_CONTEXT1_PROTECTION_FAULT_ADDR);
 	status = RREG32(mmVM_CONTEXT1_PROTECTION_FAULT_STATUS);
 	mc_client = RREG32(mmVM_CONTEXT1_PROTECTION_FAULT_MCCLIENT);
-- 
2.7.4