From 7366aeb77cd840f3edea02c65065d40affaa7f45 Mon Sep 17 00:00:00 2001
From: Xiaolin Zhang <xiaolin.zhang@intel.com>
Date: Thu, 18 Jul 2019 01:10:24 +0800
Subject: [PATCH] drm/i915/gvt: fix incorrect cache entry for guest page mapping
Git-commit: 7366aeb77cd840f3edea02c65065d40affaa7f45
Patch-mainline: v5.3-rc3
References: bsc#1111666

GPU hang observed during the guest OCL conformance test which is caused
by THP GTT feature used durning the test.

It was observed the same GFN with different size (4K and 2M) requested
from the guest in GVT. So during the guest page dma map stage, it is
required to unmap first with orginal size and then remap again with
requested size.

Fixes: b901b252b6cf ("drm/i915/gvt: Add 2M huge gtt support")
Cc: stable@vger.kernel.org
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Xiaolin Zhang <xiaolin.zhang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/gvt/kvmgt.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 144301b778df..23aa3e50cbf8 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1904,6 +1904,18 @@ static int kvmgt_dma_map_guest_page(unsigned long handle, unsigned long gfn,
 
 	entry = __gvt_cache_find_gfn(info->vgpu, gfn);
 	if (!entry) {
+		ret = gvt_dma_map_page(vgpu, gfn, dma_addr, size);
+		if (ret)
+			goto err_unlock;
+
+		ret = __gvt_cache_add(info->vgpu, gfn, *dma_addr, size);
+		if (ret)
+			goto err_unmap;
+	} else if (entry->size != size) {
+		/* the same gfn with different size: unmap and re-map */
+		gvt_dma_unmap_page(vgpu, gfn, entry->dma_addr, entry->size);
+		__gvt_cache_remove_entry(vgpu, entry);
+
 		ret = gvt_dma_map_page(vgpu, gfn, dma_addr, size);
 		if (ret)
 			goto err_unlock;
-- 
2.16.4