[Intel-xe] [PATCH v2 3/6] drm/xe/query: restrict system wide accounting

[Gwan-gyeong Mun]

looks good to me.

btw, it is similar to the constraint attribute described in this article,
https://docs.kernel.org/gpu/rfc/i915_small_bar.html#probed-cpu-visible-size-attribute
do you have any plan to add a small bar related doc for xe?

Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>

On 3/23/23 1:59 PM, Matthew Auld wrote:
> Since this is considered an info leak (system wide accounting), rather
> hide behind perfmon_capable().
> 
> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> Cc: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> Cc: José Roberto de Souza <jose.souza at intel.com>
> Cc: Filip Hazubski <filip.hazubski at intel.com>
> Cc: Carl Zhang <carl.zhang at intel.com>
> Cc: Effie Yu <effie.yu at intel.com>
> ---
>   drivers/gpu/drm/xe/xe_query.c | 17 ++++++++++++++---
>   1 file changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_query.c b/drivers/gpu/drm/xe/xe_query.c
> index 0f70945176f6..9ff806cafcdd 100644
> --- a/drivers/gpu/drm/xe/xe_query.c
> +++ b/drivers/gpu/drm/xe/xe_query.c
> @@ -127,7 +127,10 @@ static int query_memory_usage(struct xe_device *xe,
>   	usage->regions[0].min_page_size = PAGE_SIZE;
>   	usage->regions[0].max_page_size = PAGE_SIZE;
>   	usage->regions[0].total_size = man->size << PAGE_SHIFT;
> -	usage->regions[0].used = ttm_resource_manager_usage(man);
> +	if (perfmon_capable())
> +		usage->regions[0].used = ttm_resource_manager_usage(man);
> +	else
> +		usage->regions[0].used = usage->regions[0].total_size;
>   	usage->num_regions = 1;
>   
>   	for (i = XE_PL_VRAM0; i <= XE_PL_VRAM1; ++i) {
> @@ -144,8 +147,16 @@ static int query_memory_usage(struct xe_device *xe,
>   				SZ_1G;
>   			usage->regions[usage->num_regions].total_size =
>   				man->size;
> -			usage->regions[usage->num_regions++].used =
> -				ttm_resource_manager_usage(man);
> +
> +			if (perfmon_capable()) {
> +				usage->regions[usage->num_regions].used =
> +					ttm_resource_manager_usage(man);
> +			} else {
> +				usage->regions[usage->num_regions].used =
> +					man->size;
> +			}
> +
> +			usage->num_regions++;
>   		}
>   	}
>