Re: [PATCH 4/6] drm/amdgpu: Reuse fw_vram_usage_* for dynamic critical region in SRIOV

["Christian König" <christian.koenig@amd.com>]

On 09.10.25 05:30, Ellen Pan wrote:
> - During guest driver init, asa VFs receive PF msg to
> 	init dynamic critical region(v2), VFs reuse fw_vram_usage_*
> 	 from ttm to store critical region tables in a 5MB chunk.
> 
> Signed-off-by: Ellen Pan <yunru.pan@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c  | 33 +++++++++++++-----------
>  drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c |  8 ++++++
>  2 files changed, 26 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 96bd0185f936..4ba34ba74671 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1943,23 +1943,26 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
>  	if (r)
>  		return r;
>  
> -	/*
> -	 *The reserved vram for driver must be pinned to the specified
> -	 *place on the VRAM, so reserve it early.
> -	 */
> -	r = amdgpu_ttm_drv_reserve_vram_init(adev);
> -	if (r)
> -		return r;
> -
> -	/*
> -	 * only NAVI10 and onwards ASIC support for IP discovery.
> -	 * If IP discovery enabled, a block of memory should be
> -	 * reserved for IP discovey.
> -	 */
> -	if (adev->mman.discovery_bin) {
> -		r = amdgpu_ttm_reserve_tmr(adev);
> +	/* VFs using dynamic critical regions(v2) won't need to reserve for below memory */
> +	if (!amdgpu_sriov_vf(adev) || (adev->virt.req_init_data_ver != GPU_CRIT_REGION_V2)) {

That comment says what is done, but not why it is done.

> +		/*
> +		 *The reserved vram for driver must be pinned to the specified
> +		 *place on the VRAM, so reserve it early.
> +		 */
> +		r = amdgpu_ttm_drv_reserve_vram_init(adev);
>  		if (r)
>  			return r;
> +
> +		/*
> +		 * only NAVI10 and onwards ASIC support for IP discovery.
> +		 * If IP discovery enabled, a block of memory should be
> +		 * reserved for IP discovey.

While at it there are a couple of typos in the comment, please fix.

> +		 */
> +		if (adev->mman.discovery_bin) {
> +			r = amdgpu_ttm_reserve_tmr(adev);
> +			if (r)
> +				return r;
> +		}
>  	}
>  
>  	/* allocate memory as required for VGA
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> index 46c19e96086a..e9dbab53cb06 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
> @@ -931,6 +931,14 @@ int amdgpu_virt_init_critical_region(struct amdgpu_device *adev)
>  		adev->virt.crit_region_sizes_kb[AMD_SRIOV_MSG_BAD_PAGE_INFO_TABLE_ID] =
>  			init_data_hdr->bad_page_size_in_kb;
>  
> +		/* reserved memory starts from crit region base offset with the size of 5MB */
> +		adev->mman.fw_vram_usage_start_offset = adev->virt.crit_region_base_offset;
> +		adev->mman.fw_vram_usage_size = adev->virt.crit_region_size_in_kb << 10;
> +		DRM_INFO("critical region v%d requested to reserve memory start at %08x with %d KB.\n",
> +			  init_data_hdr->version,
> +			  adev->mman.fw_vram_usage_start_offset,
> +			  adev->mman.fw_vram_usage_size >> 10);
> +

Same as on the other patch, using dev_info might be more adequate than DRM_INFO.

Regards,
Christian.

>  		adev->virt.init_data_done = true;
>  		break;
>  	default: