From: Xiong Zhang <xiong.y.zhang@intel.com>
Date: Tue, 6 Mar 2018 06:07:28 +0800
Subject: drm/i915/gvt: Return error at the failure of finding page_track
Git-commit: 991ecefbdd4b81719597d6c406df8d26ef5c1546
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

In XenGT, ioreq copy is used to trap mmio write and ppgtt write. Both
of them are memory write, ioreq handler couldn't distinguish them. So
ioreq handler probe the ppgtt write handler, if it is succuess, this
ioreq is ppgtt write, otherwise it is mmio write.

So ppgtt write handler should return an error at the failure of finding
page track, it is fatal to implement ioreq handler in XenGT.

Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/gvt/page_track.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/gvt/page_track.c
+++ b/drivers/gpu/drm/i915/gvt/page_track.c
@@ -164,8 +164,10 @@ int intel_vgpu_page_track_handler(struct
 	mutex_lock(&gvt->lock);
 
 	page_track = intel_vgpu_find_page_track(vgpu, gpa >> PAGE_SHIFT);
-	if (!page_track)
+	if (!page_track) {
+		ret = -ENXIO;
 		goto out;
+	}
 
 	if (unlikely(vgpu->failsafe)) {
 		/* Remove write protection to prevent furture traps. */