drm/i915/gvt: move intel iommu detection to intel_gvt_init()

Prepare to remove detect_host() hook. Move intel iommu detection early
in intel_gvt_init().
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/gvt.c

@@ -77,6 +77,13 @@ int intel_gvt_init_host(void)
 	if (xen_domain() && !xen_initial_domain())
 		return -ENODEV;
 
+#ifdef CONFIG_INTEL_IOMMU
+	if (intel_iommu_gfx_mapped) {
+		gvt_err("Hardware IOMMU compatibility not yet supported, try to boot with intel_iommu=igfx_off\n");
+		return -ENODEV;
+	}
+#endif
+
 	/* Try to load MPT modules for hypervisors */
 	if (xen_initial_domain()) {
 		/* In Xen dom0 */

drivers/gpu/drm/i915/gvt/kvmgt.c

@@ -1276,12 +1276,6 @@ static bool kvmgt_check_guest(void)
  */
 static int kvmgt_detect_host(void)
 {
-#ifdef CONFIG_INTEL_IOMMU
-	if (intel_iommu_gfx_mapped) {
-		gvt_err("Hardware IOMMU compatibility not yet supported, try to boot with intel_iommu=igfx_off\n");
-		return -ENODEV;
-	}
-#endif
 	return kvmgt_check_guest() ? -ENODEV : 0;
 }