[PATCH] drm/i915/gvt: always return zero if read pvinfo failed

[Weinan Li]

There is pvinfo reading come from vgpu might be failed, like reading
from one unknown address, now GVT-g returns the vreg which is one
uncertain value. To avoid misunderstanding, GVT-g will always return
zero if reading failed occurred.

Signed-off-by: Weinan Li <weinan.z.li at intel.com>
---
 drivers/gpu/drm/i915/gvt/handlers.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
index a6ade66349bd..eab657d65276 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -1199,9 +1199,12 @@ static int pvinfo_mmio_read(struct intel_vgpu *vgpu, unsigned int offset,
 		invalid_read = true;
 		break;
 	}
-	if (invalid_read)
-		gvt_vgpu_err("invalid pvinfo read: [%x:%x] = %x\n",
+	if (invalid_read) {
+		gvt_vgpu_err("invalid pvinfo read: [0x%x:0x%x] = 0x0 instead of 0x%x\n",
 				offset, bytes, *(u32 *)p_data);
+		memset(p_data, 0, bytes);
+	}
+
 	vgpu->pv_notified = true;
 	return 0;
 }
-- 
2.17.1