On pre-gmc9 PTE prt bit is completely ignored.
Check the OpenGL spec for PRTs, writes needs to be ignored and reads
must return zero.
Not sure about Vulkan and OpenCL.
Christian.
Am 03.01.19 um 10:56 schrieb Zhou, David(ChunMing):
> Doesn't gpu check PTE prt bit first and then access va range?
>
> Even wrte to dummy page, seem there still is no problem, we don't care that content at all.
>
> -David
>
>> -----Original Message-----
>> From: Christian König <ckoenig.leichtzumerken@xxxxxxxxx>
>> Sent: Thursday, January 03, 2019 5:54 PM
>> To: Zhou, David(ChunMing) <David1.Zhou@xxxxxxx>; Koenig, Christian
>> <Christian.Koenig@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>> Subject: Re: [PATCH 2/2] drm/amdgpu: disable vm fault irq during prt
>> accessed
>>
>> Writes are then not ignored and garbage the dummy page.
>>
>> Christian.
>>
>> Am 03.01.19 um 10:46 schrieb Zhou, David(ChunMing):
>>> Seems we don't need two page table, we just map every prt range to
>> dummy page, any problem?
>>> -David
>>>
>>>> -----Original Message-----
>>>> From: Zhou, David(ChunMing)
>>>> Sent: Thursday, January 03, 2019 5:23 PM
>>>> To: Koenig, Christian <Christian.Koenig@xxxxxxx>; amd-
>>>> gfx@xxxxxxxxxxxxxxxxxxxxx
>>>> Subject: RE: [PATCH 2/2] drm/amdgpu: disable vm fault irq during prt
>>>> accessed
>>>>
>>>>
>>>>
>>>>> -----Original Message-----
>>>>> From: Christian König <ckoenig.leichtzumerken@xxxxxxxxx>
>>>>> Sent: Thursday, January 03, 2019 5:05 PM
>>>>> To: Zhou, David(ChunMing) <David1.Zhou@xxxxxxx>; Koenig, Christian
>>>>> <Christian.Koenig@xxxxxxx>; Zhou, David(ChunMing)
>>>>> <David1.Zhou@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>>>>> Subject: Re: [PATCH 2/2] drm/amdgpu: disable vm fault irq during prt
>>>>> accessed
>>>>>
>>>>> Yes, exactly.
>>>>>
>>>>> Problem is that we then probably need two page tables. One for the
>>>>> CB/TC and one for the SDMA.
>>>> But when setup page table, how can we know the client is CB/TC or SDMA?
>>>>
>>>> -David
>>>>
>>>>> Christian.
>>>>>
>>>>> Am 03.01.19 um 10:02 schrieb zhoucm1:
>>>>>> need dummy page for that?
>>>>>>
>>>>>>
>>>>>> -David
>>>>>>
>>>>>>
>>>>>> On 2019年01月03日 17:01, Christian König wrote:
>>>>>>> NAK, the problem is not the interrupt.
>>>>>>>
>>>>>>> E.g. causing faults by accessing unmapped pages with the SDMA can
>>>>>>> still crash the MC.
>>>>>>>
>>>>>>> The key point is that SDMA can't work with PRT tiles on pre-gmc9
>>>>>>> and we need to forbid access on the application side.
>>>>>>>
>>>>>>> Regards,
>>>>>>> Christian.
>>>>>>>
>>>>>>> Am 03.01.19 um 09:54 schrieb Chunming Zhou:
>>>>>>>> For pre-gmc9, UMD can only access unmapped PRT tile from CB/TC
>>>>>>>> without firing VM fault. Kernel would still receive the VM fault
>>>>>>>> interrupt and output the error message if SDMA is the mc_client.
>>>>>>>> GMC9 don't need the same since it handle the PRT in different way.
>>>>>>>> We cannot just skip message for SDMA, as Christian pointed, VM
>>>>>>>> fault could crash mc block, so we disable vm fault irq during prt
>>>>>>>> range is accesed.
>>>>>>>> The nagative is normal vm fault could be ignored during that
>>>>>>>> peroid without enabling vm_debug kernel parameter.
>>>>>>>>
>>>>>>>> Change-Id: Ic3c62393768eca90e3e45eaf81e7f26f2e91de84
>>>>>>>> Signed-off-by: Chunming Zhou <david1.zhou@xxxxxxx>
>>>>>>>> ---
>>>>>>>> drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c | 6 ++++++
>>>>>>>> drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 6 ++++++
>>>>>>>> drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 6 ++++++
>>>>>>>> 3 files changed, 18 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
>>>>>>>> index dae73f6768c2..175c4b319559 100644
>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
>>>>>>>> @@ -486,6 +486,10 @@ static void gmc_v6_0_set_prt(struct
>>>>>>>> amdgpu_device *adev, bool enable)
>>>>>>>> WREG32(mmVM_PRT_APERTURE1_HIGH_ADDR, high);
>>>>>>>> WREG32(mmVM_PRT_APERTURE2_HIGH_ADDR, high);
>>>>>>>> WREG32(mmVM_PRT_APERTURE3_HIGH_ADDR, high);
>>>>>>>> + /* Note: when vm_debug enabled, vm fault from SDMAx
>>>>>>>> +accessing
>>>>>>>> + * PRT range is normal. */
>>>>>>>> + if (!amdgpu_vm_debug)
>>>>>>>> + amdgpu_irq_put(adev, &adev->gmc.vm_fault, 0);
>>>>>>>> } else {
>>>>>>>> WREG32(mmVM_PRT_APERTURE0_LOW_ADDR, 0xfffffff);
>>>>>>>> WREG32(mmVM_PRT_APERTURE1_LOW_ADDR, 0xfffffff);
>> @@ -
>>>>> 495,6
>>>>>>>> +499,8 @@ static void gmc_v6_0_set_prt(struct amdgpu_device
>>>> *adev,
>>>>>>>> bool enable)
>>>>>>>> WREG32(mmVM_PRT_APERTURE1_HIGH_ADDR, 0x0);
>>>>>>>> WREG32(mmVM_PRT_APERTURE2_HIGH_ADDR, 0x0);
>>>>>>>> WREG32(mmVM_PRT_APERTURE3_HIGH_ADDR, 0x0);
>>>>>>>> + if (!amdgpu_vm_debug)
>>>>>>>> + amdgpu_irq_get(adev, &adev->gmc.vm_fault, 0);
>>>>>>>> }
>>>>>>>> }
>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>>>>>>> index 5bdeb358bfb5..a4d6d219f4e8 100644
>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
>>>>>>>> @@ -582,6 +582,10 @@ static void gmc_v7_0_set_prt(struct
>>>>>>>> amdgpu_device *adev, bool enable)
>>>>>>>> WREG32(mmVM_PRT_APERTURE1_HIGH_ADDR, high);
>>>>>>>> WREG32(mmVM_PRT_APERTURE2_HIGH_ADDR, high);
>>>>>>>> WREG32(mmVM_PRT_APERTURE3_HIGH_ADDR, high);
>>>>>>>> + /* Note: when vm_debug enabled, vm fault from SDMAx
>>>>>>>> +accessing
>>>>>>>> + * PRT range is normal. */
>>>>>>>> + if (!amdgpu_vm_debug)
>>>>>>>> + amdgpu_irq_put(adev, &adev->gmc.vm_fault, 0);
>>>>>>>> } else {
>>>>>>>> WREG32(mmVM_PRT_APERTURE0_LOW_ADDR, 0xfffffff);
>>>>>>>> WREG32(mmVM_PRT_APERTURE1_LOW_ADDR, 0xfffffff);
>> @@ -
>>>>> 591,6
>>>>>>>> +595,8 @@ static void gmc_v7_0_set_prt(struct amdgpu_device
>>>> *adev,
>>>>>>>> bool enable)
>>>>>>>> WREG32(mmVM_PRT_APERTURE1_HIGH_ADDR, 0x0);
>>>>>>>> WREG32(mmVM_PRT_APERTURE2_HIGH_ADDR, 0x0);
>>>>>>>> WREG32(mmVM_PRT_APERTURE3_HIGH_ADDR, 0x0);
>>>>>>>> + if (!amdgpu_vm_debug)
>>>>>>>> + amdgpu_irq_get(adev, &adev->gmc.vm_fault, 0);
>>>>>>>> }
>>>>>>>> }
>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>>>>>>> index 5150ab614eaa..eea2eb7fc2f5 100644
>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
>>>>>>>> @@ -808,6 +808,10 @@ static void gmc_v8_0_set_prt(struct
>>>>>>>> amdgpu_device *adev, bool enable)
>>>>>>>> WREG32(mmVM_PRT_APERTURE1_HIGH_ADDR, high);
>>>>>>>> WREG32(mmVM_PRT_APERTURE2_HIGH_ADDR, high);
>>>>>>>> WREG32(mmVM_PRT_APERTURE3_HIGH_ADDR, high);
>>>>>>>> + /* Note: when vm_debug enabled, vm fault from SDMAx
>>>>>>>> +accessing
>>>>>>>> + * PRT range is normal. */
>>>>>>>> + if (!amdgpu_vm_debug)
>>>>>>>> + amdgpu_irq_put(adev, &adev->gmc.vm_fault, 0);
>>>>>>>> } else {
>>>>>>>> WREG32(mmVM_PRT_APERTURE0_LOW_ADDR, 0xfffffff);
>>>>>>>> WREG32(mmVM_PRT_APERTURE1_LOW_ADDR, 0xfffffff);
>> @@ -
>>>>> 817,6
>>>>>>>> +821,8 @@ static void gmc_v8_0_set_prt(struct amdgpu_device
>>>> *adev,
>>>>>>>> bool enable)
>>>>>>>> WREG32(mmVM_PRT_APERTURE1_HIGH_ADDR, 0x0);
>>>>>>>> WREG32(mmVM_PRT_APERTURE2_HIGH_ADDR, 0x0);
>>>>>>>> WREG32(mmVM_PRT_APERTURE3_HIGH_ADDR, 0x0);
>>>>>>>> + if (!amdgpu_vm_debug)
>>>>>>>> + amdgpu_irq_get(adev, &adev->gmc.vm_fault, 0);
>>>>>>>> }
>>>>>>>> }
>>>>>> _______________________________________________
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>>>>>> amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>>>>>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
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