[libvirt] [PATCH 1/4] qemu: migration: Split source and destination migration checks

[Peter Krempa]

Extract the hostdev check from qemuMigrationIsAllowed into a separate
function since that is the only part that needs to be done in the v2
migration protocol prepare phase on the destination. All other checks
were added when the v3 protocol existed so that they don't need to be
extracted.

This change will allow to dro the @def argument for
qemuMigrationIsAllowed and further simplify the function.
---
 src/qemu/qemu_migration.c | 44 +++++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index fa81a16..8f28bd5 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -2156,6 +2156,34 @@ qemuMigrationDriveMirror(virQEMUDriverPtr driver,
 }


+/**
+ * qemuMigrationIsAllowedHostdev:
+ * @def: domain definition
+ *
+ * Checks that @def does not contain any host devices unsupported accross
+ * migrations. Returns true if the vm is allowed to migrate.
+ */
+static bool
+qemuMigrationIsAllowedHostdev(const virDomainDef *def)
+{
+    size_t i;
+
+    /* Migration with USB host devices is allowed, all other devices are
+     * forbidden. */
+    for (i = 0; i < def->nhostdevs; i++) {
+        virDomainHostdevDefPtr hostdev = def->hostdevs[i];
+        if (hostdev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS ||
+            hostdev->source.subsys.type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB) {
+            virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                           _("domain has assigned non-USB host devices"));
+            return false;
+        }
+    }
+
+    return true;
+}
+
+
 /* Validate whether the domain is safe to migrate.  If vm is NULL,
  * then this is being run in the v2 Prepare stage on the destination
  * (where we only have the target xml); if vm is provided, then this
@@ -2213,17 +2241,8 @@ qemuMigrationIsAllowed(virQEMUDriverPtr driver, virDomainObjPtr vm,
         def = vm->def;
     }

-    /* Migration with USB host devices is allowed, all other devices are
-     * forbidden. */
-    for (i = 0; i < def->nhostdevs; i++) {
-        virDomainHostdevDefPtr hostdev = def->hostdevs[i];
-        if (hostdev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS ||
-            hostdev->source.subsys.type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB) {
-            virReportError(VIR_ERR_OPERATION_INVALID, "%s",
-                           _("domain has assigned non-USB host devices"));
-            return false;
-        }
-    }
+    if (!qemuMigrationIsAllowedHostdev(def))
+        return false;

     if (def->cpu && def->cpu->mode != VIR_CPU_MODE_HOST_PASSTHROUGH) {
         for (i = 0; i < def->cpu->nfeatures; i++) {
@@ -3195,7 +3214,6 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver,
     unsigned int cookieFlags;
     virCapsPtr caps = NULL;
     char *migrateFrom = NULL;
-    bool abort_on_error = !!(flags & VIR_MIGRATE_ABORT_ON_ERROR);
     bool taint_hook = false;

     virNWFilterReadLockFilterUpdates();
@@ -3225,7 +3243,7 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver,
     if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
         goto cleanup;

-    if (!qemuMigrationIsAllowed(driver, NULL, *def, true, abort_on_error))
+    if (!qemuMigrationIsAllowedHostdev(*def))
         goto cleanup;

     /* Let migration hook filter domain XML */
-- 
2.4.5