[PATCH v2] drm/i915/gvt: Handle GEN9_WM_CHICKEN3 with F_CMD_ACCESS for BXT.

[Colin Xu]

On 8/17/18 3:24 PM, Zhenyu Wang wrote:

> On 2018.08.17 09:35:47 +0800, Colin Xu wrote:
>> On 8/17/18 8:44 AM, Colin Xu wrote:
>>> On 8/17/18 8:02 AM, Zhao Yan wrote:
>>>> GEN9_WM_CHICKEN3 is contained in render engine ctx, so it's
>>>> reasonable to
>>>> have F_CMD_ACCESS flag.
>>>> one concern is that GEN9_WM_CHICKEN3 should be command accessible in skl
>>>> also, although in skl platform there's no LRI to program it yet. so
>>>> do we
>>>> need to limit platform as D_BXT here?
>>> It seems GEN9_WM_CHICKEN3 is only applied to BXT now in i915. I'll
>>> double check
>>> the behaviour SKL and KBL platform and update later.
>> Confirmed that no such issue happens on SKL or KBL.
> Even no workaround applied with it, if from HW aspect it should be F_CMD_ACCESS,
> then I think we need to take that too.

I'll move it to init_skl_mmio_info() and mark as D_SKL_PLUS so that they can share the
same handling logic. Thanks for the suggestion.

>>>> On Thu, Aug 16, 2018 at 03:58:25PM +0800, Colin Xu wrote:
>>>>> Recent patch introduce strict check on scanning cmd:
>>>>> Commit 8d458ea0ec33 ("drm/i915/gvt: return error on cmd access")
>>>>>
>>>>> Before 8d458ea0ec33, if cmd_reg_handler() checks that a cmd
>>>>> access a mmio
>>>>> that not marked as F_CMD_ACCESS, it simply returns 0 and log an error.
>>>>> Now it will return -EBADRQC which will cause the workload fail
>>>>> to submit.
>>>>>
>>>>> On BXT, i915 applies WaClearHIZ_WM_CHICKEN3 which will program
>>>>> GEN9_WM_CHICKEN3 by LRI when init wa ctx. If it has no
>>>>> F_CMD_ACCESS flag,
>>>>> vgpu will fail to start. Also add F_MODE_MASK since it's mode mask reg.
>>>>>
>>>>> v2: Refresh commit message to elaborate issue symptom in detail.
>>>>>
>>>>> Signed-off-by: Colin Xu <colin.xu at intel.com>
>>>>> ---
>>>>>    drivers/gpu/drm/i915/gvt/handlers.c | 2 ++
>>>>>    1 file changed, 2 insertions(+)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/i915/gvt/handlers.c
>>>>> b/drivers/gpu/drm/i915/gvt/handlers.c
>>>>> index cf2a4020949d..e32a69fabda3 100644
>>>>> --- a/drivers/gpu/drm/i915/gvt/handlers.c
>>>>> +++ b/drivers/gpu/drm/i915/gvt/handlers.c
>>>>> @@ -3205,6 +3205,8 @@ static int init_bxt_mmio_info(struct
>>>>> intel_gvt *gvt)
>>>>>        MMIO_D(GEN8_L3SQCREG1, D_BXT);
>>>>>          MMIO_DFH(GEN9_CTX_PREEMPT_REG, D_BXT, F_CMD_ACCESS,
>>>>> NULL, NULL);
>>>>> +    MMIO_DFH(GEN9_WM_CHICKEN3, D_BXT,
>>>>> +         F_MODE_MASK | F_CMD_ACCESS, NULL, NULL);
>>>>>          return 0;
>>>>>    }
>>>>> -- 
>>>>> 2.18.0
>>>>>
>>>>> _______________________________________________
>>>>> intel-gvt-dev mailing list
>>>>> intel-gvt-dev at lists.freedesktop.org
>>>>> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
>>>> _______________________________________________
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>> -- 
>> Best Regards,
>> Colin Xu
>>
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>
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-- 
Best Regards,
Colin Xu