Re: [PATCH 1/1] drm/xe/eustall: Do not support EU stall on SRIOV VF

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Sun, 20 Apr 2025 22:59:01 -0700, Harish Chegondi wrote:
>
> EU stall sampling is not supported on SRIOV VF. Do not
> initialize or open EU stall stream on SRIOV VF.
>
> Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_eu_stall.c | 3 +++
>  drivers/gpu/drm/xe/xe_eu_stall.h | 3 ++-
>  2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_eu_stall.c b/drivers/gpu/drm/xe/xe_eu_stall.c
> index f2bb9168967c..64788277ea52 100644
> --- a/drivers/gpu/drm/xe/xe_eu_stall.c
> +++ b/drivers/gpu/drm/xe/xe_eu_stall.c
> @@ -208,6 +208,9 @@ int xe_eu_stall_init(struct xe_gt *gt)
>	struct xe_device *xe = gt_to_xe(gt);
>	int ret;
>
> +	if (!xe_eu_stall_supported_on_platform(xe))
> +		return 0;

This check is not strictly needed. If the check is not there, just some
unnecessary stuff will get initialized.

But if you want to add this check here, you will also need to a
'if (!gt->eu_stall)' check in xe_eu_stall_fini(). If you test this patch,
maybe you will already see oops when unloading the driver?

So either remove this check or add the additional check in
xe_eu_stall_fini().

> +
>	gt->eu_stall = kzalloc(sizeof(*gt->eu_stall), GFP_KERNEL);
>	if (!gt->eu_stall) {
>		ret = -ENOMEM;
> diff --git a/drivers/gpu/drm/xe/xe_eu_stall.h b/drivers/gpu/drm/xe/xe_eu_stall.h
> index ed9d0f233566..d1c76e503799 100644
> --- a/drivers/gpu/drm/xe/xe_eu_stall.h
> +++ b/drivers/gpu/drm/xe/xe_eu_stall.h
> @@ -7,6 +7,7 @@
>  #define __XE_EU_STALL_H__
>
>  #include "xe_gt_types.h"
> +#include "xe_sriov.h"
>
>  size_t xe_eu_stall_get_per_xecore_buf_size(void);
>  size_t xe_eu_stall_data_record_size(struct xe_device *xe);
> @@ -19,6 +20,6 @@ int xe_eu_stall_stream_open(struct drm_device *dev,
>
>  static inline bool xe_eu_stall_supported_on_platform(struct xe_device *xe)
>  {
> -	return xe->info.platform == XE_PVC || GRAPHICS_VER(xe) >= 20;
> +	return !IS_SRIOV_VF(xe) && (xe->info.platform == XE_PVC || GRAPHICS_VER(xe) >= 20);
>  }
>  #endif
> --
> 2.48.1
>