[PATCH v2] drm/i915/gvt: set shadow entry point to scratch page while p2m failed

[Zhi Wang]

Ha. Thanks! :P

于 03/20/17 15:14, Gao, Ping A 写道:
>
> On 2017/3/17 10:29, Xiaoguang Chen wrote:
>> Sometimes guest driver will write part of the GGTT entry(4 bytes)then
>> use it which will lead to a failure while trying to translate the gpa
>> to hpa.
>> Now in this situation we let the shadow entry pointing to a scratch page.
>>
>> Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>
>> Signed-off-by: Xiaoguang Chen <xiaoguang.chen at intel.com>
>> ---
>>   drivers/gpu/drm/i915/gvt/gtt.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
>> index da73127..3bae2e5 100644
>> --- a/drivers/gpu/drm/i915/gvt/gtt.c
>> +++ b/drivers/gpu/drm/i915/gvt/gtt.c
>> @@ -1837,11 +1837,11 @@ static int emulate_gtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off,
>>   		ret = gtt_entry_p2m(vgpu, &e, &m);
>>   		if (ret) {
>>   			gvt_vgpu_err("fail to translate guest gtt entry\n");
>> -			return ret;
>> +			ops->set_pfn(&m, vgpu->gtt.scratch_pt[GTT_TYPE_GGTT_PTE].page_mfn);
>
> Here should use GTT_TYPE_PPGTT_PTE_PT.
>
>>   		}
>>   	} else {
>>   		m = e;
>> -		m.val64 = 0;
>> +		ops->set_pfn(&m, vgpu->gtt.scratch_pt[GTT_TYPE_GGTT_PTE].page_mfn);
>>   	}
>>
>>   	ggtt_set_shadow_entry(ggtt_mm, &m, g_gtt_index);
>