qemu: process: move disk presence checking to host setup function

Checking of disk presence accesses storage on the host so it should be
done from the host setup function. Move the code to new function called
qemuProcessPrepareHostStorage and remove qemuDomainCheckDiskPresence.

src/qemu/qemu_domain.c

@@ -5681,47 +5681,6 @@ qemuDomainCheckDiskStartupPolicy(virQEMUDriverPtr driver,
 }
 
 
-int
-qemuDomainCheckDiskPresence(virQEMUDriverPtr driver,
-                            virDomainObjPtr vm,
-                            unsigned int flags)
-{
-    size_t i;
-    bool pretend = flags & VIR_QEMU_PROCESS_START_PRETEND;
-    bool cold_boot = flags & VIR_QEMU_PROCESS_START_COLD;
-
-    VIR_DEBUG("Checking for disk presence");
-    for (i = vm->def->ndisks; i > 0; i--) {
-        size_t idx = i - 1;
-        virDomainDiskDefPtr disk = vm->def->disks[idx];
-        virStorageFileFormat format = virDomainDiskGetFormat(disk);
-
-        if (pretend)
-            continue;
-
-        if (virStorageSourceIsEmpty(disk->src))
-            continue;
-
-        /* There is no need to check the backing chain for disks
-         * without backing support, the fact that the file exists is
-         * more than enough */
-        if (virStorageSourceIsLocalStorage(disk->src) &&
-            format > VIR_STORAGE_FILE_NONE &&
-            format < VIR_STORAGE_FILE_BACKING &&
-            virFileExists(virDomainDiskGetSource(disk)))
-            continue;
-
-        if (qemuDomainDetermineDiskChain(driver, vm, disk, true, true) >= 0)
-            continue;
-
-        if (qemuDomainCheckDiskStartupPolicy(driver, vm, idx, cold_boot) >= 0)
-            continue;
-
-        return -1;
-    }
-
-    return 0;
-}
 
 /*
  * The vm must be locked when any of the following cleanup functions is

src/qemu/qemu_process.c

@@ -5394,10 +5394,6 @@ qemuProcessPrepareDomain(virConnectPtr conn,
     if (qemuProcessPrepareDomainStorage(conn, driver, vm, cfg, flags) < 0)
         goto cleanup;
 
-    /* Drop possibly missing disks from the definition. */
-    if (qemuDomainCheckDiskPresence(driver, vm, flags) < 0)
-        goto cleanup;
-
     VIR_DEBUG("Create domain masterKey");
     if (qemuDomainMasterKeyCreate(vm) < 0)
         goto cleanup;
@@ -5444,6 +5440,44 @@ qemuProcessPrepareDomain(virConnectPtr conn,
 }
 
 
+static int
+qemuProcessPrepareHostStorage(virQEMUDriverPtr driver,
+                              virDomainObjPtr vm,
+                              unsigned int flags)
+{
+    size_t i;
+    bool cold_boot = flags & VIR_QEMU_PROCESS_START_COLD;
+
+    for (i = vm->def->ndisks; i > 0; i--) {
+        size_t idx = i - 1;
+        virDomainDiskDefPtr disk = vm->def->disks[idx];
+        virStorageFileFormat format = virDomainDiskGetFormat(disk);
+
+        if (virStorageSourceIsEmpty(disk->src))
+            continue;
+
+        /* There is no need to check the backing chain for disks
+         * without backing support, the fact that the file exists is
+         * more than enough */
+        if (virStorageSourceIsLocalStorage(disk->src) &&
+            format > VIR_STORAGE_FILE_NONE &&
+            format < VIR_STORAGE_FILE_BACKING &&
+            virFileExists(virDomainDiskGetSource(disk)))
+            continue;
+
+        if (qemuDomainDetermineDiskChain(driver, vm, disk, true, true) >= 0)
+            continue;
+
+        if (qemuDomainCheckDiskStartupPolicy(driver, vm, idx, cold_boot) >= 0)
+            continue;
+
+        return -1;
+    }
+
+    return 0;
+}
+
+
 /**
  * qemuProcessPrepareHost:
  * @driver: qemu driver
@@ -5536,6 +5570,10 @@ qemuProcessPrepareHost(virQEMUDriverPtr driver,
     if (qemuDomainWriteMasterKeyFile(driver, vm) < 0)
         goto cleanup;
 
+    VIR_DEBUG("Preparing disks (host)");
+    if (qemuProcessPrepareHostStorage(driver, vm, flags) < 0)
+        goto cleanup;
+
     ret = 0;
  cleanup:
     virObjectUnref(cfg);