drm/xe/vf: Fix GuC FW check for VF migration support

The check whether GuC ABI version meets requirements shall be
performed after said version is received from GuC.

Doing it in wrong order was triggering a warning:
xe 0000:00:02.1: [drm] Assertion `gt->sriov.vf.guc_version.major` failed!

With this change, dislodge part of the VF migration support check
and moved it to after GuC handshake.

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Tested-by: Matthew Brost <matthew.brost@intel.com> #v1
Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6349
Fixes: ff1d2b5e3d28 ("drm/xe: Read VF GMD_ID with a specifically-allocated dummy GT")
Signed-off-by: Tomasz Lis <tomasz.lis@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://lore.kernel.org/r/20251021224817.1593817-3-tomasz.lis@intel.com

3 files changed, 57 insertions, 23 deletions

diff --git a/drivers/gpu/drm/xe/xe_sriov_vf.c b/drivers/gpu/drm/xe/xe_sriov_vf.c
index 0d8135f3927c..13d6c094ae8f 100644
--- a/drivers/gpu/drm/xe/xe_sriov_vf.c
+++ b/drivers/gpu/drm/xe/xe_sriov_vf.c
@@ -133,7 +133,12 @@ bool xe_sriov_vf_migration_supported(struct xe_device *xe)
 	return !xe->sriov.vf.migration.disabled;
 }
 
-static void vf_disable_migration(struct xe_device *xe, const char *fmt, ...)
+/**
+ * xe_sriov_vf_migration_disable - Turn off VF migration with given log message.
+ * @xe: the &xe_device instance.
+ * @fmt: format string for the log message, to be combined with following VAs.
+ */
+void xe_sriov_vf_migration_disable(struct xe_device *xe, const char *fmt, ...)
 {
 	struct va_format vaf;
 	va_list va_args;
@@ -156,22 +161,13 @@ static void vf_migration_init_early(struct xe_device *xe)
 	 * supported at production quality.
 	 */
 	if (!IS_ENABLED(CONFIG_DRM_XE_DEBUG))
-		return vf_disable_migration(xe,
-					    "experimental feature not available on production builds");
+		return xe_sriov_vf_migration_disable(xe,
+				"experimental feature not available on production builds");
 
 	if (GRAPHICS_VER(xe) < 20)
-		return vf_disable_migration(xe, "requires gfx version >= 20, but only %u found",
-					    GRAPHICS_VER(xe));
-
-	if (!IS_DGFX(xe)) {
-		struct xe_uc_fw_version guc_version;
-
-		xe_gt_sriov_vf_guc_versions(xe_device_get_gt(xe, 0), NULL, &guc_version);
-		if (MAKE_GUC_VER_STRUCT(guc_version) < MAKE_GUC_VER(1, 23, 0))
-			return vf_disable_migration(xe,
-						    "CCS migration requires GuC ABI >= 1.23 but only %u.%u found",
-						    guc_version.major, guc_version.minor);
-	}
+		return xe_sriov_vf_migration_disable(xe,
+				"requires gfx version >= 20, but only %u found",
+				GRAPHICS_VER(xe));
 }
 
 /**
@@ -193,12 +189,7 @@ void xe_sriov_vf_init_early(struct xe_device *xe)
  */
 int xe_sriov_vf_init_late(struct xe_device *xe)
 {
-	int err = 0;
-
-	if (xe_sriov_vf_migration_supported(xe))
-		err = xe_sriov_vf_ccs_init(xe);
-
-	return err;
+	return xe_sriov_vf_ccs_init(xe);
 }
 
 static int sa_info_vf_ccs(struct seq_file *m, void *data)
diff --git a/drivers/gpu/drm/xe/xe_sriov_vf.h b/drivers/gpu/drm/xe/xe_sriov_vf.h
index 4df95266b261..e967d4166a43 100644
--- a/drivers/gpu/drm/xe/xe_sriov_vf.h
+++ b/drivers/gpu/drm/xe/xe_sriov_vf.h
@@ -14,6 +14,7 @@ struct xe_device;
 void xe_sriov_vf_init_early(struct xe_device *xe);
 int xe_sriov_vf_init_late(struct xe_device *xe);
 bool xe_sriov_vf_migration_supported(struct xe_device *xe);
+void xe_sriov_vf_migration_disable(struct xe_device *xe, const char *fmt, ...);
 void xe_sriov_vf_debugfs_register(struct xe_device *xe, struct dentry *root);
 
 #endif
diff --git a/drivers/gpu/drm/xe/xe_sriov_vf_ccs.c b/drivers/gpu/drm/xe/xe_sriov_vf_ccs.c
index 790249801364..797a4b866226 100644
--- a/drivers/gpu/drm/xe/xe_sriov_vf_ccs.c
+++ b/drivers/gpu/drm/xe/xe_sriov_vf_ccs.c
@@ -10,6 +10,8 @@
 #include "xe_device.h"
 #include "xe_exec_queue.h"
 #include "xe_exec_queue_types.h"
+#include "xe_gt_sriov_vf.h"
+#include "xe_guc.h"
 #include "xe_guc_submit.h"
 #include "xe_lrc.h"
 #include "xe_migrate.h"
@@ -260,6 +262,45 @@ int xe_sriov_vf_ccs_register_context(struct xe_device *xe)
 	return err;
 }
 
+/*
+ * Whether GuC requires CCS copy BBs for VF migration.
+ * @xe: the &xe_device instance.
+ *
+ * Only selected platforms require VF KMD to maintain CCS copy BBs and linked LRCAs.
+ *
+ * Return: true if VF driver must participate in the CCS migration, false otherwise.
+ */
+static bool vf_migration_ccs_bb_needed(struct xe_device *xe)
+{
+	xe_assert(xe, IS_SRIOV_VF(xe));
+
+	return !IS_DGFX(xe) && xe_device_has_flat_ccs(xe);
+}
+
+/*
+ * Check for disable migration due to no CCS BBs support in GuC FW.
+ * @xe: the &xe_device instance.
+ *
+ * Performs late disable of VF migration feature in case GuC FW cannot support it.
+ *
+ * Returns: True if VF migration with CCS BBs is supported, false otherwise.
+ */
+static bool vf_migration_ccs_bb_support_check(struct xe_device *xe)
+{
+	struct xe_gt *gt = xe_root_mmio_gt(xe);
+	struct xe_uc_fw_version guc_version;
+
+	xe_gt_sriov_vf_guc_versions(gt, NULL, &guc_version);
+	if (MAKE_GUC_VER_STRUCT(guc_version) < MAKE_GUC_VER(1, 23, 0)) {
+		xe_sriov_vf_migration_disable(xe,
+					      "CCS migration requires GuC ABI >= 1.23 but only %u.%u found",
+					      guc_version.major, guc_version.minor);
+		return false;
+	}
+
+	return true;
+}
+
 static void xe_sriov_vf_ccs_fini(void *arg)
 {
 	struct xe_sriov_vf_ccs_ctx *ctx = arg;
@@ -292,9 +333,10 @@ int xe_sriov_vf_ccs_init(struct xe_device *xe)
 	int err;
 
 	xe_assert(xe, IS_SRIOV_VF(xe));
-	xe_assert(xe, xe_sriov_vf_migration_supported(xe));
 
-	if (IS_DGFX(xe) || !xe_device_has_flat_ccs(xe))
+	if (!xe_sriov_vf_migration_supported(xe) ||
+	    !vf_migration_ccs_bb_needed(xe) ||
+	    !vf_migration_ccs_bb_support_check(xe))
 		return 0;
 
 	for_each_ccs_rw_ctx(ctx_id) {