drm/xe/pf: Enable SR-IOV VF migration

All of the necessary building blocks are now in place to support SR-IOV
VF migration.
Flip the enable/disable logic to match VF code and disable the feature
only for platforms that don't meet the necessary prerequisites.
To allow more testing and experiments, on DEBUG builds any missing
prerequisites will be ignored.

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patch.msgid.link/20251127093934.1462188-2-michal.winiarski@intel.com
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
(cherry picked from commit 01c724a)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

Author: mwiniars

drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c

@@ -17,6 +17,7 @@
 #include "xe_gt_sriov_pf_helpers.h"
 #include "xe_gt_sriov_pf_migration.h"
 #include "xe_gt_sriov_printk.h"
+#include "xe_guc.h"
 #include "xe_guc_buf.h"
 #include "xe_guc_ct.h"
 #include "xe_migrate.h"
@@ -1023,6 +1024,12 @@ static void action_ring_cleanup(void *arg)
 	ptr_ring_cleanup(r, destroy_pf_packet);
 }
 
+static void pf_gt_migration_check_support(struct xe_gt *gt)
+{
+	if (GUC_FIRMWARE_VER(&gt->uc.guc) < MAKE_GUC_VER(70, 54, 0))
+		xe_sriov_pf_migration_disable(gt_to_xe(gt), "requires GuC version >= 70.54.0");
+}
+
 /**
  * xe_gt_sriov_pf_migration_init() - Initialize support for VF migration.
  * @gt: the &xe_gt
@@ -1039,6 +1046,8 @@ int xe_gt_sriov_pf_migration_init(struct xe_gt *gt)
 
 	xe_gt_assert(gt, IS_SRIOV_PF(xe));
 
+	pf_gt_migration_check_support(gt);
+
 	if (!pf_migration_supported(gt))
 		return 0;
 

drivers/gpu/drm/xe/xe_sriov_pf_migration.c

@@ -46,13 +46,37 @@ bool xe_sriov_pf_migration_supported(struct xe_device *xe)
 {
 	xe_assert(xe, IS_SRIOV_PF(xe));
 
-	return xe->sriov.pf.migration.supported;
+	return IS_ENABLED(CONFIG_DRM_XE_DEBUG) || !xe->sriov.pf.migration.disabled;
 }
 
-static bool pf_check_migration_support(struct xe_device *xe)
+/**
+ * xe_sriov_pf_migration_disable() - Turn off SR-IOV VF migration support on PF.
+ * @xe: the &xe_device instance.
+ * @fmt: format string for the log message, to be combined with following VAs.
+ */
+void xe_sriov_pf_migration_disable(struct xe_device *xe, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list va_args;
+
+	xe_assert(xe, IS_SRIOV_PF(xe));
+
+	va_start(va_args, fmt);
+	vaf.fmt = fmt;
+	vaf.va  = &va_args;
+	xe_sriov_notice(xe, "migration %s: %pV\n",
+			IS_ENABLED(CONFIG_DRM_XE_DEBUG) ?
+			"missing prerequisite" : "disabled",
+			&vaf);
+	va_end(va_args);
+
+	xe->sriov.pf.migration.disabled = true;
+}
+
+static void pf_migration_check_support(struct xe_device *xe)
 {
-	/* XXX: for now this is for feature enabling only */
-	return IS_ENABLED(CONFIG_DRM_XE_DEBUG);
+	if (!xe_device_has_memirq(xe))
+		xe_sriov_pf_migration_disable(xe, "requires memory-based IRQ support");
 }
 
 static void pf_migration_cleanup(void *arg)
@@ -77,7 +101,8 @@ int xe_sriov_pf_migration_init(struct xe_device *xe)
 
 	xe_assert(xe, IS_SRIOV_PF(xe));
 
-	xe->sriov.pf.migration.supported = pf_check_migration_support(xe);
+	pf_migration_check_support(xe);
+
 	if (!xe_sriov_pf_migration_supported(xe))
 		return 0;
 

drivers/gpu/drm/xe/xe_sriov_pf_migration.h

@@ -14,6 +14,7 @@ struct xe_sriov_packet;
 
 int xe_sriov_pf_migration_init(struct xe_device *xe);
 bool xe_sriov_pf_migration_supported(struct xe_device *xe);
+void xe_sriov_pf_migration_disable(struct xe_device *xe, const char *fmt, ...);
 int xe_sriov_pf_migration_restore_produce(struct xe_device *xe, unsigned int vfid,
 					  struct xe_sriov_packet *data);
 struct xe_sriov_packet *

drivers/gpu/drm/xe/xe_sriov_pf_migration_types.h

@@ -14,8 +14,8 @@
  * struct xe_sriov_pf_migration - Xe device level VF migration data
  */
 struct xe_sriov_pf_migration {
-	/** @supported: indicates whether VF migration feature is supported */
-	bool supported;
+	/** @disabled: indicates whether VF migration feature is disabled */
+	bool disabled;
 };
 
 /**