drm/xe/pf: Force new VFs prorities only once

We should force change of VFs scheduling priorities only after
initial change of the SCHED_IF_IDLE policy. Doing that also during
any later policy reprovisioning will overwrite changes done on the
individual per-VF scheduling priorities (currently only for PF).

While around also move priority change code to the _config component
to maintain a proper isolation. Also document our expectation about
the GuC version where the new meaning of the policy KLV is present.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patch.msgid.link/20260402191726.4932-4-michal.wajdeczko@intel.com

diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
index 658e9b048751d6e6631bfdd9d1c7f8a564c70408..c74745642a9257a04b1a7e2333fbdf2247fde7bb 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
@@ -2550,6 +2550,35 @@ u32 xe_gt_sriov_pf_config_get_sched_priority(struct xe_gt *gt, unsigned int vfid
        return priority;
 }
 
+/**
+ * xe_gt_sriov_pf_config_force_sched_priority_locked() - Force update scheduling priority.
+ * @gt: the &xe_gt
+ * @priority: new scheduling priority to set
+ *
+ * This function allows to update cached values of the scheduling priorities of all
+ * VFs (and PF) as result of applying the `GUC_KLV_VGT_POLICY_SCHED_IF_IDLE`_ policy.
+ *
+ * This function can only be called on PF.
+ */
+void xe_gt_sriov_pf_config_force_sched_priority_locked(struct xe_gt *gt, u32 priority)
+{
+       unsigned int total_vfs = 1 + xe_gt_sriov_pf_get_totalvfs(gt);
+       struct xe_gt_sriov_config *config;
+       unsigned int n;
+
+       xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
+       lockdep_assert_held(xe_gt_sriov_pf_master_mutex(gt));
+
+       for (n = 0; n < total_vfs; n++) {
+               config = pf_pick_vf_config(gt, VFID(n));
+               config->sched_priority = priority;
+       }
+
+       pf_config_bulk_set_u32_done(gt, PFID, 1 + total_vfs, priority,
+                                   pf_get_sched_priority, "scheduling priority",
+                                   sched_priority_unit, n, 0);
+}
+
 static void pf_reset_config_sched(struct xe_gt *gt, struct xe_gt_sriov_config *config)
 {
        int i;

diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
index 4a004ecd614066b55ffadba7e24a0fb396f3ac84..e9314f0a9b4ea21590c951efd4b54b29d96a2da0 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
@@ -71,6 +71,7 @@ int xe_gt_sriov_pf_config_set_groups_preempt_timeouts(struct xe_gt *gt, unsigned
 
 u32 xe_gt_sriov_pf_config_get_sched_priority(struct xe_gt *gt, unsigned int vfid);
 int xe_gt_sriov_pf_config_set_sched_priority(struct xe_gt *gt, unsigned int vfid, u32 priority);
+void xe_gt_sriov_pf_config_force_sched_priority_locked(struct xe_gt *gt, u32 priority);
 
 u32 xe_gt_sriov_pf_config_get_threshold(struct xe_gt *gt, unsigned int vfid,
                                        enum xe_guc_klv_threshold_index index);

diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_policy.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_policy.c
index 848e24926ecd024e9989cc76ef679c23ecc22f4e..6ab02e96e46cbe118f7b124ecc2c34292777d445 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_policy.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_policy.c
@@ -8,6 +8,7 @@
 #include "abi/guc_actions_sriov_abi.h"
 
 #include "xe_gt.h"
+#include "xe_gt_sriov_pf_config.h"
 #include "xe_gt_sriov_pf_helpers.h"
 #include "xe_gt_sriov_pf_policy.h"
 #include "xe_gt_sriov_printk.h"
@@ -153,33 +154,14 @@ static int pf_update_policy_u32(struct xe_gt *gt, u16 key, u32 *policy, u32 valu
        return 0;
 }
 
-static void pf_bulk_reset_sched_priority(struct xe_gt *gt, u32 priority)
-{
-       unsigned int total_vfs = 1 + xe_gt_sriov_pf_get_totalvfs(gt);
-       unsigned int n;
-
-       xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
-       lockdep_assert_held(xe_gt_sriov_pf_master_mutex(gt));
-
-       for (n = 0; n < total_vfs; n++)
-               gt->sriov.pf.vfs[n].config.sched_priority = priority;
-}
-
 static int pf_provision_sched_if_idle(struct xe_gt *gt, bool enable)
 {
-       int err;
-
        xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
        lockdep_assert_held(xe_gt_sriov_pf_master_mutex(gt));
 
-       err = pf_update_policy_bool(gt, GUC_KLV_VGT_POLICY_SCHED_IF_IDLE_KEY,
-                                   &gt->sriov.pf.policy.guc.sched_if_idle,
-                                   enable);
-
-       if (!err)
-               pf_bulk_reset_sched_priority(gt, enable ? GUC_SCHED_PRIORITY_NORMAL :
-                                            GUC_SCHED_PRIORITY_LOW);
-       return err;
+       return pf_update_policy_bool(gt, GUC_KLV_VGT_POLICY_SCHED_IF_IDLE_KEY,
+                                    &gt->sriov.pf.policy.guc.sched_if_idle,
+                                    enable);
 }
 
 static int pf_reprovision_sched_if_idle(struct xe_gt *gt)
@@ -209,13 +191,25 @@ static void pf_sanitize_sched_if_idle(struct xe_gt *gt)
  */
 int xe_gt_sriov_pf_policy_set_sched_if_idle(struct xe_gt *gt, bool enable)
 {
+       u32 priority;
        int err;
 
-       mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
+       guard(mutex)(xe_gt_sriov_pf_master_mutex(gt));
+
        err = pf_provision_sched_if_idle(gt, enable);
-       mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
+       if (err)
+               return err;
 
-       return err;
+       /*
+        * As of GuC 70.12 a change of this policy impacts individual configs
+        * of all VFs. See `GUC_KLV_VGT_POLICY_SCHED_IF_IDLE`_ for details.
+        */
+       xe_gt_assert(gt, GUC_FIRMWARE_VER_AT_LEAST(&gt->uc.guc, 70, 12));
+
+       priority = enable ? GUC_SCHED_PRIORITY_NORMAL : GUC_SCHED_PRIORITY_LOW;
+       xe_gt_sriov_pf_config_force_sched_priority_locked(gt, priority);
+
+       return 0;
 }
 
 /**