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

[Colin Xu]

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.
>> 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
>> _______________________________________________
>> intel-gvt-dev mailing list
>> intel-gvt-dev at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
>
-- 
Best Regards,
Colin Xu