Re: [PATCH v3 1/4] drm/xe/reg_sr: Don't process gt/hwe lists in VF

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

On Thu, 12 Feb 2026 16:09:31 -0800, Matt Roper wrote:
>

Hi Matt,

> diff --git a/drivers/gpu/drm/xe/xe_hw_engine.c b/drivers/gpu/drm/xe/xe_hw_engine.c
> index 4d3ee5226e3a..7061312ce6b5 100644
> --- a/drivers/gpu/drm/xe/xe_hw_engine.c
> +++ b/drivers/gpu/drm/xe/xe_hw_engine.c
> @@ -472,6 +472,9 @@ hw_engine_setup_default_state(struct xe_hw_engine *hwe)
>		},
>	};
>
> +	if (IS_SRIOV_VF(gt_to_xe(gt)))
> +		return;
> +

I was thinking, instead of having this check in multiple places, this check
should be moved inside xe_rtp_process_to_sr(). And then we should tell
xe_rtp_process_to_sr() whether to skip or to continue somehow. We could
either:

a. add a "type" field (gt/hwe/lrc) to either reg_sr or to ctx, or,
b. add another 'vf' argument to xe_rtp_process_to_sr() ('vf' would be say 1
   for lrc and 0 for other cases).

And based on this information xe_rtp_process_to_sr() would either skip or
continue for VF's.

Thanks.
--
Ashutosh

>	xe_rtp_process_to_sr(&ctx, engine_entries, ARRAY_SIZE(engine_entries), &hwe->reg_sr);

>  }
>
> diff --git a/drivers/gpu/drm/xe/xe_reg_sr.c b/drivers/gpu/drm/xe/xe_reg_sr.c
> index d3e13ea33123..1ac911fc6e94 100644
> --- a/drivers/gpu/drm/xe/xe_reg_sr.c
> +++ b/drivers/gpu/drm/xe/xe_reg_sr.c
> @@ -13,6 +13,7 @@
>  #include <drm/drm_managed.h>
>  #include <drm/drm_print.h>
>
> +#include "xe_assert.h"
>  #include "xe_device.h"
>  #include "xe_device_types.h"
>  #include "xe_force_wake.h"
> @@ -169,8 +170,11 @@ void xe_reg_sr_apply_mmio(struct xe_reg_sr *sr, struct xe_gt *gt)
>	if (xa_empty(&sr->xa))
>		return;
>
> -	if (IS_SRIOV_VF(gt_to_xe(gt)))
> -		return;
> +	/*
> +	 * We don't process non-LRC reg_sr lists in VF, so they should have
> +	 * been empty in the check above.
> +	 */
> +	xe_gt_assert(gt, !IS_SRIOV_VF(gt_to_xe(gt)));
>
>	xe_gt_dbg(gt, "Applying %s save-restore MMIOs\n", sr->name);
>
> diff --git a/drivers/gpu/drm/xe/xe_reg_whitelist.c b/drivers/gpu/drm/xe/xe_reg_whitelist.c
> index 9c513778d370..83b2d1c68acf 100644
> --- a/drivers/gpu/drm/xe/xe_reg_whitelist.c
> +++ b/drivers/gpu/drm/xe/xe_reg_whitelist.c
> @@ -188,6 +188,9 @@ void xe_reg_whitelist_process_engine(struct xe_hw_engine *hwe)
>  {
>	struct xe_rtp_process_ctx ctx = XE_RTP_PROCESS_CTX_INITIALIZER(hwe);
>
> +	if (IS_SRIOV_VF(gt_to_xe(hwe->gt)))
> +		return;
> +
>	xe_rtp_process_to_sr(&ctx, register_whitelist, ARRAY_SIZE(register_whitelist),
>			     &hwe->reg_whitelist);
>	whitelist_apply_to_hwe(hwe);
> diff --git a/drivers/gpu/drm/xe/xe_tuning.c b/drivers/gpu/drm/xe/xe_tuning.c
> index 316f5e2b2e48..ddd8519f3f19 100644
> --- a/drivers/gpu/drm/xe/xe_tuning.c
> +++ b/drivers/gpu/drm/xe/xe_tuning.c
> @@ -15,6 +15,7 @@
>  #include "xe_gt_types.h"
>  #include "xe_platform_types.h"
>  #include "xe_rtp.h"
> +#include "xe_sriov.h"
>
>  #undef XE_REG_MCR
>  #define XE_REG_MCR(...)     XE_REG(__VA_ARGS__, .mcr = 1)
> @@ -197,6 +198,9 @@ void xe_tuning_process_gt(struct xe_gt *gt)
>  {
>	struct xe_rtp_process_ctx ctx = XE_RTP_PROCESS_CTX_INITIALIZER(gt);
>
> +	if (IS_SRIOV_VF(gt_to_xe(gt)))
> +		return;
> +
>	xe_rtp_process_ctx_enable_active_tracking(&ctx,
>						  gt->tuning_active.gt,
>						  ARRAY_SIZE(gt_tunings));
> @@ -208,6 +212,9 @@ void xe_tuning_process_engine(struct xe_hw_engine *hwe)
>  {
>	struct xe_rtp_process_ctx ctx = XE_RTP_PROCESS_CTX_INITIALIZER(hwe);
>
> +	if (IS_SRIOV_VF(gt_to_xe(hwe->gt)))
> +		return;
> +
>	xe_rtp_process_ctx_enable_active_tracking(&ctx,
>						  hwe->gt->tuning_active.engine,
>						  ARRAY_SIZE(engine_tunings));
> diff --git a/drivers/gpu/drm/xe/xe_wa.c b/drivers/gpu/drm/xe/xe_wa.c
> index 843ce9fe7aab..92547280a5b6 100644
> --- a/drivers/gpu/drm/xe/xe_wa.c
> +++ b/drivers/gpu/drm/xe/xe_wa.c
> @@ -1003,6 +1003,9 @@ void xe_wa_process_gt(struct xe_gt *gt)
>  {
>	struct xe_rtp_process_ctx ctx = XE_RTP_PROCESS_CTX_INITIALIZER(gt);
>
> +	if (IS_SRIOV_VF(gt_to_xe(gt)))
> +		return;
> +
>	xe_rtp_process_ctx_enable_active_tracking(&ctx, gt->wa_active.gt,
>						  ARRAY_SIZE(gt_was));
>	xe_rtp_process_to_sr(&ctx, gt_was, ARRAY_SIZE(gt_was), &gt->reg_sr);
> @@ -1021,6 +1024,9 @@ void xe_wa_process_engine(struct xe_hw_engine *hwe)
>  {
>	struct xe_rtp_process_ctx ctx = XE_RTP_PROCESS_CTX_INITIALIZER(hwe);
>
> +	if (IS_SRIOV_VF(gt_to_xe(hwe->gt)))
> +		return;
> +
>	xe_rtp_process_ctx_enable_active_tracking(&ctx, hwe->gt->wa_active.engine,
>						  ARRAY_SIZE(engine_was));
>	xe_rtp_process_to_sr(&ctx, engine_was, ARRAY_SIZE(engine_was), &hwe->reg_sr);
> --
> 2.53.0
>