[v2] drm/amdgpu: Default disable GDS for compute VMIDs

Submitted by Greathouse, Joseph on July 17, 2019, 6:23 p.m.

Details

Message ID 20190717182233.93031-1-Joseph.Greathouse@amd.com
State Accepted
Commit fbdc5d8d84cc521573f1265d5e6ceb04a16075c9
Headers show
Series "drm/amdgpu: Default disable GDS for compute VMIDs" ( rev: 2 ) in AMD X.Org drivers

Not browsing as part of any series.

Commit Message

Greathouse, Joseph July 17, 2019, 6:23 p.m.
The GDS and GWS blocks default to allowing all VMIDs to
access all entries. Graphics VMIDs can handle setting
these limits when the driver launches work. However,
compute workloads under HWS control don't go through the
kernel driver. Instead, HWS firmware should set these
limits when a process is put into a VMID slot.

Disable access to these devices by default by turning off
all mask bits (for OA) and setting BASE=SIZE=0 (for GDS
and GWS) for all compute VMIDs. If a process wants to use
these resources, they can request this from the HWS
firmware (when such capabilities are enabled). HWS will
then handle setting the base and limit for the process when
it is assigned to a VMID.

This will also prevent user kernels from getting 'stuck' in
GWS by accident if they write GWS-using code but HWS
firmware is not set up to handle GWS reset. Until HWS is
enabled to handle GWS properly, all GWS accesses will
MEM_VIOL fault the kernel.

v2: Move initialization outside of SRBM mutex

Change-Id: I8edcea9d0b14d16a7444bcf9fbf9451aef8b707d
Signed-off-by: Joseph Greathouse <Joseph.Greathouse@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 9 +++++++++
 drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c  | 9 +++++++++
 drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c  | 9 +++++++++
 drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c  | 9 +++++++++
 4 files changed, 36 insertions(+)

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
index 618291df659b..73dcb632a3ce 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
@@ -1516,6 +1516,15 @@  static void gfx_v10_0_init_compute_vmid(struct amdgpu_device *adev)
 	}
 	nv_grbm_select(adev, 0, 0, 0, 0);
 	mutex_unlock(&adev->srbm_mutex);
+
+	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
+	   acccess. These should be enabled by FW for target VMIDs. */
+	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_BASE, 2 * i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_SIZE, 2 * i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_GWS_VMID0, i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_OA_VMID0, i, 0);
+	}
 }
 
 static void gfx_v10_0_tcp_harvest(struct amdgpu_device *adev)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
index e1e2a44ee13c..3f98624772a4 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
@@ -1877,6 +1877,15 @@  static void gfx_v7_0_init_compute_vmid(struct amdgpu_device *adev)
 	}
 	cik_srbm_select(adev, 0, 0, 0, 0);
 	mutex_unlock(&adev->srbm_mutex);
+
+	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
+	   acccess. These should be enabled by FW for target VMIDs. */
+	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
+		WREG32(amdgpu_gds_reg_offset[i].mem_base, 0);
+		WREG32(amdgpu_gds_reg_offset[i].mem_size, 0);
+		WREG32(amdgpu_gds_reg_offset[i].gws, 0);
+		WREG32(amdgpu_gds_reg_offset[i].oa, 0);
+	}
 }
 
 static void gfx_v7_0_config_init(struct amdgpu_device *adev)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
index 8c590a554675..e4028d54f8f7 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
@@ -3702,6 +3702,15 @@  static void gfx_v8_0_init_compute_vmid(struct amdgpu_device *adev)
 	}
 	vi_srbm_select(adev, 0, 0, 0, 0);
 	mutex_unlock(&adev->srbm_mutex);
+
+	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
+	   acccess. These should be enabled by FW for target VMIDs. */
+	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
+		WREG32(amdgpu_gds_reg_offset[i].mem_base, 0);
+		WREG32(amdgpu_gds_reg_offset[i].mem_size, 0);
+		WREG32(amdgpu_gds_reg_offset[i].gws, 0);
+		WREG32(amdgpu_gds_reg_offset[i].oa, 0);
+	}
 }
 
 static void gfx_v8_0_config_init(struct amdgpu_device *adev)
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 5af60e1c735a..259a35395fec 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -2025,6 +2025,15 @@  static void gfx_v9_0_init_compute_vmid(struct amdgpu_device *adev)
 	}
 	soc15_grbm_select(adev, 0, 0, 0, 0);
 	mutex_unlock(&adev->srbm_mutex);
+
+	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
+	   acccess. These should be enabled by FW for target VMIDs. */
+	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_BASE, 2 * i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_SIZE, 2 * i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_GWS_VMID0, i, 0);
+		WREG32_SOC15_OFFSET(GC, 0, mmGDS_OA_VMID0, i, 0);
+	}
 }
 
 static void gfx_v9_0_constants_init(struct amdgpu_device *adev)

Comments

On 2019-07-17 14:23, Greathouse, Joseph wrote:
> The GDS and GWS blocks default to allowing all VMIDs to

> access all entries. Graphics VMIDs can handle setting

> these limits when the driver launches work. However,

> compute workloads under HWS control don't go through the

> kernel driver. Instead, HWS firmware should set these

> limits when a process is put into a VMID slot.

>

> Disable access to these devices by default by turning off

> all mask bits (for OA) and setting BASE=SIZE=0 (for GDS

> and GWS) for all compute VMIDs. If a process wants to use

> these resources, they can request this from the HWS

> firmware (when such capabilities are enabled). HWS will

> then handle setting the base and limit for the process when

> it is assigned to a VMID.

>

> This will also prevent user kernels from getting 'stuck' in

> GWS by accident if they write GWS-using code but HWS

> firmware is not set up to handle GWS reset. Until HWS is

> enabled to handle GWS properly, all GWS accesses will

> MEM_VIOL fault the kernel.

>

> v2: Move initialization outside of SRBM mutex

>

> Change-Id: I8edcea9d0b14d16a7444bcf9fbf9451aef8b707d

> Signed-off-by: Joseph Greathouse <Joseph.Greathouse@amd.com>


Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>



> ---

>   drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 9 +++++++++

>   drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c  | 9 +++++++++

>   drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c  | 9 +++++++++

>   drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c  | 9 +++++++++

>   4 files changed, 36 insertions(+)

>

> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c

> index 618291df659b..73dcb632a3ce 100644

> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c

> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c

> @@ -1516,6 +1516,15 @@ static void gfx_v10_0_init_compute_vmid(struct amdgpu_device *adev)

>   	}

>   	nv_grbm_select(adev, 0, 0, 0, 0);

>   	mutex_unlock(&adev->srbm_mutex);

> +

> +	/* Initialize all compute VMIDs to have no GDS, GWS, or OA

> +	   acccess. These should be enabled by FW for target VMIDs. */

> +	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {

> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_BASE, 2 * i, 0);

> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_SIZE, 2 * i, 0);

> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_GWS_VMID0, i, 0);

> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_OA_VMID0, i, 0);

> +	}

>   }

>   

>   static void gfx_v10_0_tcp_harvest(struct amdgpu_device *adev)

> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c

> index e1e2a44ee13c..3f98624772a4 100644

> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c

> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c

> @@ -1877,6 +1877,15 @@ static void gfx_v7_0_init_compute_vmid(struct amdgpu_device *adev)

>   	}

>   	cik_srbm_select(adev, 0, 0, 0, 0);

>   	mutex_unlock(&adev->srbm_mutex);

> +

> +	/* Initialize all compute VMIDs to have no GDS, GWS, or OA

> +	   acccess. These should be enabled by FW for target VMIDs. */

> +	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {

> +		WREG32(amdgpu_gds_reg_offset[i].mem_base, 0);

> +		WREG32(amdgpu_gds_reg_offset[i].mem_size, 0);

> +		WREG32(amdgpu_gds_reg_offset[i].gws, 0);

> +		WREG32(amdgpu_gds_reg_offset[i].oa, 0);

> +	}

>   }

>   

>   static void gfx_v7_0_config_init(struct amdgpu_device *adev)

> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c

> index 8c590a554675..e4028d54f8f7 100644

> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c

> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c

> @@ -3702,6 +3702,15 @@ static void gfx_v8_0_init_compute_vmid(struct amdgpu_device *adev)

>   	}

>   	vi_srbm_select(adev, 0, 0, 0, 0);

>   	mutex_unlock(&adev->srbm_mutex);

> +

> +	/* Initialize all compute VMIDs to have no GDS, GWS, or OA

> +	   acccess. These should be enabled by FW for target VMIDs. */

> +	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {

> +		WREG32(amdgpu_gds_reg_offset[i].mem_base, 0);

> +		WREG32(amdgpu_gds_reg_offset[i].mem_size, 0);

> +		WREG32(amdgpu_gds_reg_offset[i].gws, 0);

> +		WREG32(amdgpu_gds_reg_offset[i].oa, 0);

> +	}

>   }

>   

>   static void gfx_v8_0_config_init(struct amdgpu_device *adev)

> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c

> index 5af60e1c735a..259a35395fec 100644

> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c

> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c

> @@ -2025,6 +2025,15 @@ static void gfx_v9_0_init_compute_vmid(struct amdgpu_device *adev)

>   	}

>   	soc15_grbm_select(adev, 0, 0, 0, 0);

>   	mutex_unlock(&adev->srbm_mutex);

> +

> +	/* Initialize all compute VMIDs to have no GDS, GWS, or OA

> +	   acccess. These should be enabled by FW for target VMIDs. */

> +	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {

> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_BASE, 2 * i, 0);

> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_SIZE, 2 * i, 0);

> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_GWS_VMID0, i, 0);

> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_OA_VMID0, i, 0);

> +	}

>   }

>   

>   static void gfx_v9_0_constants_init(struct amdgpu_device *adev)
Am 17.07.19 um 22:09 schrieb Kuehling, Felix:
> On 2019-07-17 14:23, Greathouse, Joseph wrote:
>> The GDS and GWS blocks default to allowing all VMIDs to
>> access all entries. Graphics VMIDs can handle setting
>> these limits when the driver launches work. However,
>> compute workloads under HWS control don't go through the
>> kernel driver. Instead, HWS firmware should set these
>> limits when a process is put into a VMID slot.
>>
>> Disable access to these devices by default by turning off
>> all mask bits (for OA) and setting BASE=SIZE=0 (for GDS
>> and GWS) for all compute VMIDs. If a process wants to use
>> these resources, they can request this from the HWS
>> firmware (when such capabilities are enabled). HWS will
>> then handle setting the base and limit for the process when
>> it is assigned to a VMID.
>>
>> This will also prevent user kernels from getting 'stuck' in
>> GWS by accident if they write GWS-using code but HWS
>> firmware is not set up to handle GWS reset. Until HWS is
>> enabled to handle GWS properly, all GWS accesses will
>> MEM_VIOL fault the kernel.
>>
>> v2: Move initialization outside of SRBM mutex
>>
>> Change-Id: I8edcea9d0b14d16a7444bcf9fbf9451aef8b707d
>> Signed-off-by: Joseph Greathouse <Joseph.Greathouse@amd.com>
> Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>

Might be a good idea to do this for all VMIDs during initialization and 
not just for the ones used for compute.

But anyway patch is Reviewed-by: Christian König <christian.koenig@amd.com>.

>
>
>> ---
>>    drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c | 9 +++++++++
>>    drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c  | 9 +++++++++
>>    drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c  | 9 +++++++++
>>    drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c  | 9 +++++++++
>>    4 files changed, 36 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
>> index 618291df659b..73dcb632a3ce 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c
>> @@ -1516,6 +1516,15 @@ static void gfx_v10_0_init_compute_vmid(struct amdgpu_device *adev)
>>    	}
>>    	nv_grbm_select(adev, 0, 0, 0, 0);
>>    	mutex_unlock(&adev->srbm_mutex);
>> +
>> +	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
>> +	   acccess. These should be enabled by FW for target VMIDs. */
>> +	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
>> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_BASE, 2 * i, 0);
>> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_SIZE, 2 * i, 0);
>> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_GWS_VMID0, i, 0);
>> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_OA_VMID0, i, 0);
>> +	}
>>    }
>>    
>>    static void gfx_v10_0_tcp_harvest(struct amdgpu_device *adev)
>> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
>> index e1e2a44ee13c..3f98624772a4 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c
>> @@ -1877,6 +1877,15 @@ static void gfx_v7_0_init_compute_vmid(struct amdgpu_device *adev)
>>    	}
>>    	cik_srbm_select(adev, 0, 0, 0, 0);
>>    	mutex_unlock(&adev->srbm_mutex);
>> +
>> +	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
>> +	   acccess. These should be enabled by FW for target VMIDs. */
>> +	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
>> +		WREG32(amdgpu_gds_reg_offset[i].mem_base, 0);
>> +		WREG32(amdgpu_gds_reg_offset[i].mem_size, 0);
>> +		WREG32(amdgpu_gds_reg_offset[i].gws, 0);
>> +		WREG32(amdgpu_gds_reg_offset[i].oa, 0);
>> +	}
>>    }
>>    
>>    static void gfx_v7_0_config_init(struct amdgpu_device *adev)
>> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
>> index 8c590a554675..e4028d54f8f7 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
>> @@ -3702,6 +3702,15 @@ static void gfx_v8_0_init_compute_vmid(struct amdgpu_device *adev)
>>    	}
>>    	vi_srbm_select(adev, 0, 0, 0, 0);
>>    	mutex_unlock(&adev->srbm_mutex);
>> +
>> +	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
>> +	   acccess. These should be enabled by FW for target VMIDs. */
>> +	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
>> +		WREG32(amdgpu_gds_reg_offset[i].mem_base, 0);
>> +		WREG32(amdgpu_gds_reg_offset[i].mem_size, 0);
>> +		WREG32(amdgpu_gds_reg_offset[i].gws, 0);
>> +		WREG32(amdgpu_gds_reg_offset[i].oa, 0);
>> +	}
>>    }
>>    
>>    static void gfx_v8_0_config_init(struct amdgpu_device *adev)
>> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
>> index 5af60e1c735a..259a35395fec 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
>> @@ -2025,6 +2025,15 @@ static void gfx_v9_0_init_compute_vmid(struct amdgpu_device *adev)
>>    	}
>>    	soc15_grbm_select(adev, 0, 0, 0, 0);
>>    	mutex_unlock(&adev->srbm_mutex);
>> +
>> +	/* Initialize all compute VMIDs to have no GDS, GWS, or OA
>> +	   acccess. These should be enabled by FW for target VMIDs. */
>> +	for (i = FIRST_COMPUTE_VMID; i < LAST_COMPUTE_VMID; i++) {
>> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_BASE, 2 * i, 0);
>> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_VMID0_SIZE, 2 * i, 0);
>> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_GWS_VMID0, i, 0);
>> +		WREG32_SOC15_OFFSET(GC, 0, mmGDS_OA_VMID0, i, 0);
>> +	}
>>    }
>>    
>>    static void gfx_v9_0_constants_init(struct amdgpu_device *adev)
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> -----Original Message-----

> From: Christian König <ckoenig.leichtzumerken@gmail.com>

> Sent: Thursday, July 18, 2019 3:14 AM

> To: Kuehling, Felix <Felix.Kuehling@amd.com>; Greathouse, Joseph

> <Joseph.Greathouse@amd.com>; amd-gfx@lists.freedesktop.org

> Subject: Re: [PATCH v2] drm/amdgpu: Default disable GDS for compute

> VMIDs

> 

> Am 17.07.19 um 22:09 schrieb Kuehling, Felix:

> > On 2019-07-17 14:23, Greathouse, Joseph wrote:

> >> The GDS and GWS blocks default to allowing all VMIDs to

> >> access all entries. Graphics VMIDs can handle setting

> >> these limits when the driver launches work. However,

> >> compute workloads under HWS control don't go through the

> >> kernel driver. Instead, HWS firmware should set these

> >> limits when a process is put into a VMID slot.

> >>

> >> Disable access to these devices by default by turning off

> >> all mask bits (for OA) and setting BASE=SIZE=0 (for GDS

> >> and GWS) for all compute VMIDs. If a process wants to use

> >> these resources, they can request this from the HWS

> >> firmware (when such capabilities are enabled). HWS will

> >> then handle setting the base and limit for the process when

> >> it is assigned to a VMID.

> >>

> >> This will also prevent user kernels from getting 'stuck' in

> >> GWS by accident if they write GWS-using code but HWS

> >> firmware is not set up to handle GWS reset. Until HWS is

> >> enabled to handle GWS properly, all GWS accesses will

> >> MEM_VIOL fault the kernel.

> >>

> >> v2: Move initialization outside of SRBM mutex

> >>

> >> Change-Id: I8edcea9d0b14d16a7444bcf9fbf9451aef8b707d

> >> Signed-off-by: Joseph Greathouse <Joseph.Greathouse@amd.com>

> > Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>

> 

> Might be a good idea to do this for all VMIDs during initialization and

> not just for the ones used for compute.

> 

> But anyway patch is Reviewed-by: Christian König

> <christian.koenig@amd.com>.


Hmm, good point. It looks like graphics jobs will eventually call through to emit_gds_switch() to set these when launching a job, but it may be worthwhile to set these to zero as a default. I didn't want to step on any toes on the graphics side without checking first.

Do you have opinions on the most reasonable location to do this? early_init(), late_init()? The various gfx_v*_set_gds_init() might be a good place -- a quick test of setting all 16 VMIDs in gfx_v9_0_set_gds_init() appears to work fine on my Vega 20.

-Joe
Am 18.07.19 um 22:46 schrieb Greathouse, Joseph:
>> -----Original Message-----

>> From: Christian König <ckoenig.leichtzumerken@gmail.com>

>> Sent: Thursday, July 18, 2019 3:14 AM

>> To: Kuehling, Felix <Felix.Kuehling@amd.com>; Greathouse, Joseph

>> <Joseph.Greathouse@amd.com>; amd-gfx@lists.freedesktop.org

>> Subject: Re: [PATCH v2] drm/amdgpu: Default disable GDS for compute

>> VMIDs

>>

>> Am 17.07.19 um 22:09 schrieb Kuehling, Felix:

>>> On 2019-07-17 14:23, Greathouse, Joseph wrote:

>>>> The GDS and GWS blocks default to allowing all VMIDs to

>>>> access all entries. Graphics VMIDs can handle setting

>>>> these limits when the driver launches work. However,

>>>> compute workloads under HWS control don't go through the

>>>> kernel driver. Instead, HWS firmware should set these

>>>> limits when a process is put into a VMID slot.

>>>>

>>>> Disable access to these devices by default by turning off

>>>> all mask bits (for OA) and setting BASE=SIZE=0 (for GDS

>>>> and GWS) for all compute VMIDs. If a process wants to use

>>>> these resources, they can request this from the HWS

>>>> firmware (when such capabilities are enabled). HWS will

>>>> then handle setting the base and limit for the process when

>>>> it is assigned to a VMID.

>>>>

>>>> This will also prevent user kernels from getting 'stuck' in

>>>> GWS by accident if they write GWS-using code but HWS

>>>> firmware is not set up to handle GWS reset. Until HWS is

>>>> enabled to handle GWS properly, all GWS accesses will

>>>> MEM_VIOL fault the kernel.

>>>>

>>>> v2: Move initialization outside of SRBM mutex

>>>>

>>>> Change-Id: I8edcea9d0b14d16a7444bcf9fbf9451aef8b707d

>>>> Signed-off-by: Joseph Greathouse <Joseph.Greathouse@amd.com>

>>> Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>

>> Might be a good idea to do this for all VMIDs during initialization and

>> not just for the ones used for compute.

>>

>> But anyway patch is Reviewed-by: Christian König

>> <christian.koenig@amd.com>.

> Hmm, good point. It looks like graphics jobs will eventually call through to emit_gds_switch() to set these when launching a job, but it may be worthwhile to set these to zero as a default. I didn't want to step on any toes on the graphics side without checking first.

>

> Do you have opinions on the most reasonable location to do this? early_init(), late_init()? The various gfx_v*_set_gds_init() might be a good place -- a quick test of setting all 16 VMIDs in gfx_v9_0_set_gds_init() appears to work fine on my Vega 20.


With the exception of the GMC all hw initialization should be in 
hw_init. So set_gds_init might work, but is certainly the wrong place.

I wouldn't mind renaming gfx_*_init_compute_vmid() into 
gfx_*_init_vmid() and setting reasonable defaults for both compute as 
well as gfx VMIDs.

Christian.

>

> -Joe