drm/xe/pf: Skip fair VFs provisioning if already provisioned

Our debugfs allows to view and change VFs' provisioning configs.

If we attempt to experiment with VFs provisioning before enabling
them, this early config will affect fair provisioning calculations,
and will also be overwritten, which is undesirable behavior.

To improve this, check if the VFs configs are empty (unprovisioned)
before starting the fair provisioning procedure.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240701102738.934-2-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 694671497f6e5bab6fd6ddf2f02db15f27f0719a..810b579a002507f28d29cab1af9b282e88bfafc1 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c
@@ -1922,6 +1922,54 @@ int xe_gt_sriov_pf_config_push(struct xe_gt *gt, unsigned int vfid, bool refresh
        return err;
 }
 
+static int pf_validate_vf_config(struct xe_gt *gt, unsigned int vfid)
+{
+       struct xe_gt *primary_gt = gt_to_tile(gt)->primary_gt;
+       struct xe_device *xe = gt_to_xe(gt);
+       bool valid_ggtt, valid_ctxs, valid_dbs;
+       bool valid_any, valid_all;
+
+       valid_ggtt = pf_get_vf_config_ggtt(primary_gt, vfid);
+       valid_ctxs = pf_get_vf_config_ctxs(gt, vfid);
+       valid_dbs = pf_get_vf_config_dbs(gt, vfid);
+
+       /* note that GuC doorbells are optional */
+       valid_any = valid_ggtt || valid_ctxs || valid_dbs;
+       valid_all = valid_ggtt && valid_ctxs;
+
+       if (IS_DGFX(xe)) {
+               bool valid_lmem = pf_get_vf_config_ggtt(primary_gt, vfid);
+
+               valid_any = valid_any || valid_lmem;
+               valid_all = valid_all && valid_lmem;
+       }
+
+       return valid_all ? 1 : valid_any ? -ENOKEY : -ENODATA;
+}
+
+/**
+ * xe_gt_sriov_pf_config_is_empty - Check VF's configuration.
+ * @gt: the &xe_gt
+ * @vfid: the VF identifier (can't be PF)
+ *
+ * This function can only be called on PF.
+ *
+ * Return: true if VF mandatory configuration (GGTT, LMEM, ...) is empty.
+ */
+bool xe_gt_sriov_pf_config_is_empty(struct xe_gt *gt, unsigned int vfid)
+{
+       bool empty;
+
+       xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
+       xe_gt_assert(gt, vfid);
+
+       mutex_lock(xe_gt_sriov_pf_master_mutex(gt));
+       empty = pf_validate_vf_config(gt, vfid) == -ENODATA;
+       mutex_unlock(xe_gt_sriov_pf_master_mutex(gt));
+
+       return empty;
+}
+
 /**
  * xe_gt_sriov_pf_config_print_ggtt - Print GGTT configurations.
  * @gt: the &xe_gt

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 e8238c1ad06adf90d0c6930a90af1fadb03effb7..58c8f879d7abebdea5bfb476dd299597ed59ff46 100644 (file)
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.h
@@ -53,6 +53,8 @@ int xe_gt_sriov_pf_config_set_fair(struct xe_gt *gt, unsigned int vfid, unsigned
 int xe_gt_sriov_pf_config_release(struct xe_gt *gt, unsigned int vfid, bool force);
 int xe_gt_sriov_pf_config_push(struct xe_gt *gt, unsigned int vfid, bool refresh);
 
+bool xe_gt_sriov_pf_config_is_empty(struct xe_gt *gt, unsigned int vfid);
+
 int xe_gt_sriov_pf_config_print_ggtt(struct xe_gt *gt, struct drm_printer *p);
 int xe_gt_sriov_pf_config_print_ctxs(struct xe_gt *gt, struct drm_printer *p);
 int xe_gt_sriov_pf_config_print_dbs(struct xe_gt *gt, struct drm_printer *p);

diff --git a/drivers/gpu/drm/xe/xe_pci_sriov.c b/drivers/gpu/drm/xe/xe_pci_sriov.c
index 74c8fadc93653a07fb77fcdf86020a94377b26db..aaceee748287ef702fd7ebeed7f082415c846548 100644 (file)
--- a/drivers/gpu/drm/xe/xe_pci_sriov.c
+++ b/drivers/gpu/drm/xe/xe_pci_sriov.c
@@ -13,6 +13,17 @@
 #include "xe_sriov_pf_helpers.h"
 #include "xe_sriov_printk.h"
 
+static int pf_needs_provisioning(struct xe_gt *gt, unsigned int num_vfs)
+{
+       unsigned int n;
+
+       for (n = 1; n <= num_vfs; n++)
+               if (!xe_gt_sriov_pf_config_is_empty(gt, n))
+                       return false;
+
+       return true;
+}
+
 static int pf_provision_vfs(struct xe_device *xe, unsigned int num_vfs)
 {
        struct xe_gt *gt;
@@ -20,6 +31,8 @@ static int pf_provision_vfs(struct xe_device *xe, unsigned int num_vfs)
        int result = 0, err;
 
        for_each_gt(gt, xe, id) {
+               if (!pf_needs_provisioning(gt, num_vfs))
+                       continue;
                err = xe_gt_sriov_pf_config_set_fair(gt, VFID(1), num_vfs);
                result = result ?: err;
        }