From 97f9ca383dca6f4b425fb3c4709405fb8272a15f Mon Sep 17 00:00:00 2001
From: Colin Xu <colin.xu@intel.com>
Date: Fri, 11 Sep 2020 14:52:39 +0800
Subject: [PATCH] drm/i915/gvt: Allow zero out HWSP addr on hws_pga_write
Guest driver may reset HWSP to 0 as init value during D3->D0:
The full sequence is:
- Boot ->D0
- Update HWSP
- D0->D3
- ...In D3 state...
- D3->D0
- DMLR reset.
- Set engine HWSP to 0.
- Set engine ring mode to 0.
- Set engine HWSP to correct value.
- Set engine ring mode to correct value.
Ring mode is masked register so set 0 won't take effect.
However HWPS addr 0 is considered as invalid GGTT address which will
report error like:
gvt: vgpu 1: write invalid HWSP address, reg:0x2080, value:0x0
gvt: vgpu 1: fail to emulate MMIO write 00002080 len 4
Detected your guest driver doesn't support GVT-g.
Now vgpu 2 will enter failsafe mode.
Zero out HWSP addr is considered as a valid setting from device driver
so don't treat it as invalid HWSP addr.
V2:
Treat HWSP addr 0 as valid. (zhenyu)
V3:
Change patch title.
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200911065239.147789-1-colin.xu@intel.com
---
drivers/gpu/drm/i915/gvt/handlers.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
index 05f3bc98d242d..388982fe3e02c 100644
--- a/drivers/gpu/drm/i915/gvt/handlers.c
+++ b/drivers/gpu/drm/i915/gvt/handlers.c
@@ -1489,7 +1489,8 @@ static int hws_pga_write(struct intel_vgpu *vgpu, unsigned int offset,
const struct intel_engine_cs *engine =
intel_gvt_render_mmio_to_engine(vgpu->gvt, offset);
- if (!intel_gvt_ggtt_validate_range(vgpu, value, I915_GTT_PAGE_SIZE)) {
+ if (value != 0 &&
+ !intel_gvt_ggtt_validate_range(vgpu, value, I915_GTT_PAGE_SIZE)) {
gvt_vgpu_err("write invalid HWSP address, reg:0x%x, value:0x%x\n",
offset, value);
return -EINVAL;
--
2.30.2