[PATCH V2 6/6] drm/i915/gvt: Check if get_next_pt_type() always returns a valid value

[Aleksei Gimbitskii]

According to gtt_type_table[] function get_next_pt_type() may returns
GTT_TYPE_INVALID in some cases. To prevent driver to try to create memory
page with invalid data type, additional check is added.

Signed-off-by: Aleksei Gimbitskii <aleksei.gimbitskii at intel.com>
Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
Cc: Zhi Wang <zhi.a.wang at intel.com>
Cc: Colin Xu <colin.xu at intel.com>
---
 drivers/gpu/drm/i915/gvt/gtt.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index 95cd8f25d6f9..c93e7a3a7f36 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -1079,6 +1079,9 @@ static struct intel_vgpu_ppgtt_spt *ppgtt_populate_spt_by_guest_entry(
 	} else {
 		int type = get_next_pt_type(we->type);
 
+		if (!gtt_type_is_pt(type))
+			goto err;
+
 		spt = ppgtt_alloc_spt_gfn(vgpu, type, ops->get_pfn(we), ips);
 		if (IS_ERR(spt)) {
 			ret = PTR_ERR(spt);
-- 
2.17.1

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