[PATCH 5.4 11/18] drm/i915/gvt: Fix port number for BDW on EDID region setup

From: Greg Kroah-Hartman
Date: Fri Mar 19 2021 - 08:20:13 EST

From: Colin Xu <colin.xu@xxxxxxxxx>

From: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>

commit 28284943ac94014767ecc2f7b3c5747c4a5617a0 upstream

Current BDW virtual display port is initialized as PORT_B, so need
to use same port for VFIO EDID region, otherwise invalid EDID blob
pointer is assigned which caused kernel null pointer reference. We
might evaluate actual display hotplug for BDW to make this function
work as expected, anyway this is always required to be fixed first.

Reported-by: Alejandro Sior <aho@xxxxxxx>
Cc: Alejandro Sior <aho@xxxxxxx>
Fixes: 0178f4ce3c3b ("drm/i915/gvt: Enable vfio edid for all GVT supported platform")
Reviewed-by: Hang Yuan <hang.yuan@xxxxxxxxx>
Signed-off-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
Link: http://patchwork.freedesktop.org/patch/msgid/20200914030302.2775505-1-zhenyuw@xxxxxxxxxxxxxxx
(cherry picked from commit 28284943ac94014767ecc2f7b3c5747c4a5617a0)
Signed-off-by: Colin Xu <colin.xu@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 5.4.y
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/gpu/drm/i915/gvt/vgpu.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -432,8 +432,9 @@ static struct intel_vgpu *__intel_gvt_cr
if (ret)
goto out_clean_sched_policy;

- /*TODO: add more platforms support */
- if (IS_SKYLAKE(gvt->dev_priv) || IS_KABYLAKE(gvt->dev_priv))
+ if (IS_BROADWELL(gvt->dev_priv))
+ ret = intel_gvt_hypervisor_set_edid(vgpu, PORT_B);
+ else
ret = intel_gvt_hypervisor_set_edid(vgpu, PORT_D);
if (ret)
goto out_clean_sched_policy;