[libvirt] [PATCH] qemu: Don't parse device twice in attach/detach

Michal Privoznik mprivozn at redhat.com
Thu Mar 1 18:56:49 UTC 2012


Some nits are generated during XML parse (e.g. MAC address of
an interface); However, with current implementation, if we
are plugging a device both to persistent and live config,
we parse given XML twice: first time for live, second for config.
This is wrong then as the second time we are not guaranteed
to generate same values as we did for the first time.
To prevent that we need to create a copy of DeviceDefPtr;
This is done through format/parse process instead of writing
functions for deep copy as it is easier to maintain:
adding new field to any virDomain*DefPtr doesn't require change
of copying function.
---
 src/conf/domain_conf.c   |   94 ++++++++++++++++++++++++++++++++++++++++++++++
 src/conf/domain_conf.h   |    3 +
 src/libvirt_private.syms |    1 +
 src/qemu/qemu_driver.c   |   40 +++++++++++--------
 4 files changed, 121 insertions(+), 17 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index f9654f1..f001319 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -14118,3 +14118,97 @@ virDomainNetFind(virDomainDefPtr def, const char *device)
 
     return net;
 }
+
+#define VIR_DOMAIN_DEVICE_FORMAT(func) \
+    if (func < 0) \
+        goto cleanup; \
+    xmlStr = virBufferContentAndReset(&buf); \
+    ret = virDomainDeviceDefParse(caps, def, xmlStr, flags)
+
+virDomainDeviceDefPtr
+virDomainDeviceDefCopy(virCapsPtr caps,
+                       const virDomainDefPtr def,
+                       virDomainDeviceDefPtr src)
+{
+    virDomainDeviceDefPtr ret = NULL;
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+    int flags = VIR_DOMAIN_XML_INACTIVE;
+    char *xmlStr = NULL;
+
+    switch(src->type) {
+    case VIR_DOMAIN_DEVICE_DISK:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainDiskDefFormat(&buf,
+                                                        src->data.disk,
+                                                        flags));
+        break;
+    case VIR_DOMAIN_DEVICE_LEASE:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainLeaseDefFormat(&buf,
+                                                         src->data.lease));
+        break;
+    case VIR_DOMAIN_DEVICE_FS:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainFSDefFormat(&buf,
+                                                      src->data.fs,
+                                                      flags));
+        break;
+    case VIR_DOMAIN_DEVICE_NET:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainNetDefFormat(&buf,
+                                                       src->data.net,
+                                                       flags));
+        break;
+    case VIR_DOMAIN_DEVICE_INPUT:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainInputDefFormat(&buf,
+                                                         src->data.input,
+                                                         flags));
+        break;
+    case VIR_DOMAIN_DEVICE_SOUND:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainSoundDefFormat(&buf,
+                                                         src->data.sound,
+                                                         flags));
+        break;
+    case VIR_DOMAIN_DEVICE_VIDEO:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainVideoDefFormat(&buf,
+                                                         src->data.video,
+                                                         flags));
+        break;
+    case VIR_DOMAIN_DEVICE_HOSTDEV:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainHostdevDefFormat(&buf,
+                                                           src->data.hostdev,
+                                                           flags));
+        break;
+    case VIR_DOMAIN_DEVICE_WATCHDOG:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainWatchdogDefFormat(&buf,
+                                                            src->data.watchdog,
+                                                            flags));
+        break;
+    case VIR_DOMAIN_DEVICE_CONTROLLER:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainControllerDefFormat(&buf,
+                                                              src->data.controller,
+                                                              flags));
+        break;
+    case VIR_DOMAIN_DEVICE_GRAPHICS:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainGraphicsDefFormat(&buf,
+                                                            src->data.graphics,
+                                                            flags));
+        break;
+    case VIR_DOMAIN_DEVICE_HUB:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainHubDefFormat(&buf,
+                                                       src->data.hub,
+                                                       flags));
+        break;
+    case VIR_DOMAIN_DEVICE_REDIRDEV:
+        VIR_DOMAIN_DEVICE_FORMAT(virDomainRedirdevDefFormat(&buf,
+                                                            src->data.redirdev,
+                                                            flags));
+        break;
+    default:
+        virDomainReportError(VIR_ERR_INTERNAL_ERROR,
+                             _("Copying definition of '%d' type "
+                               "is not implemented yet."),
+                             src->type);
+        break;
+    }
+
+cleanup:
+    VIR_FREE(xmlStr);
+    return ret;
+}
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 596be4d..7e4a464 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1750,6 +1750,9 @@ void virDomainHostdevDefFree(virDomainHostdevDefPtr def);
 void virDomainHubDefFree(virDomainHubDefPtr def);
 void virDomainRedirdevDefFree(virDomainRedirdevDefPtr def);
 void virDomainDeviceDefFree(virDomainDeviceDefPtr def);
+virDomainDeviceDefPtr virDomainDeviceDefCopy(virCapsPtr caps,
+                                             const virDomainDefPtr def,
+                                             virDomainDeviceDefPtr src);
 int virDomainDeviceAddressIsValid(virDomainDeviceInfoPtr info,
                                   int type);
 int virDomainDevicePCIAddressIsValid(virDomainDevicePCIAddressPtr addr);
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index a104e70..53f27e7 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -286,6 +286,7 @@ virDomainDeviceAddressIsValid;
 virDomainDeviceAddressPciMultiTypeFromString;
 virDomainDeviceAddressPciMultiTypeToString;
 virDomainDeviceAddressTypeToString;
+virDomainDeviceDefCopy;
 virDomainDeviceDefFree;
 virDomainDeviceDefParse;
 virDomainDeviceInfoIterate;
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index c6bdd29..3a52ded 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -5561,8 +5561,9 @@ qemuDomainModifyDeviceFlags(virDomainPtr dom, const char *xml,
     struct qemud_driver *driver = dom->conn->privateData;
     virDomainObjPtr vm = NULL;
     virDomainDefPtr vmdef = NULL;
-    virDomainDeviceDefPtr dev = NULL;
+    virDomainDeviceDefPtr dev = NULL, dev_copy = NULL;
     bool force = (flags & VIR_DOMAIN_DEVICE_MODIFY_FORCE) != 0;
+    bool free_dev_copy = false;
     int ret = -1;
     unsigned int affect;
 
@@ -5608,12 +5609,24 @@ qemuDomainModifyDeviceFlags(virDomainPtr dom, const char *xml,
          goto endjob;
     }
 
-    if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
-        dev = virDomainDeviceDefParse(driver->caps, vm->def, xml,
-                                      VIR_DOMAIN_XML_INACTIVE);
-        if (dev == NULL)
+    dev = dev_copy = virDomainDeviceDefParse(driver->caps, vm->def, xml,
+                                             VIR_DOMAIN_XML_INACTIVE);
+    if (dev == NULL)
+        goto endjob;
+
+    if (flags & VIR_DOMAIN_AFFECT_CONFIG &&
+        flags & VIR_DOMAIN_AFFECT_LIVE) {
+        /* If we are affecting both CONFIG and LIVE
+         * create a deep copy of device as adding
+         * to CONFIG takes one instance.
+         */
+        dev_copy = virDomainDeviceDefCopy(driver->caps, vm->def, dev);
+        if (!dev_copy)
             goto endjob;
+        free_dev_copy = true;
+    }
 
+    if (flags & VIR_DOMAIN_AFFECT_CONFIG) {
         /* Make a copy for updated domain. */
         vmdef = virDomainObjCopyPersistentDef(driver->caps, vm);
         if (!vmdef)
@@ -5639,24 +5652,15 @@ qemuDomainModifyDeviceFlags(virDomainPtr dom, const char *xml,
     }
 
     if (flags & VIR_DOMAIN_AFFECT_LIVE) {
-        /* If dev exists it was created to modify the domain config. Free it. */
-        virDomainDeviceDefFree(dev);
-        dev = virDomainDeviceDefParse(driver->caps, vm->def, xml,
-                                      VIR_DOMAIN_XML_INACTIVE);
-        if (dev == NULL) {
-            ret = -1;
-            goto endjob;
-        }
-
         switch (action) {
         case QEMU_DEVICE_ATTACH:
-            ret = qemuDomainAttachDeviceLive(vm, dev, dom);
+            ret = qemuDomainAttachDeviceLive(vm, dev_copy, dom);
             break;
         case QEMU_DEVICE_DETACH:
-            ret = qemuDomainDetachDeviceLive(vm, dev, dom);
+            ret = qemuDomainDetachDeviceLive(vm, dev_copy, dom);
             break;
         case QEMU_DEVICE_UPDATE:
-            ret = qemuDomainUpdateDeviceLive(vm, dev, dom, force);
+            ret = qemuDomainUpdateDeviceLive(vm, dev_copy, dom, force);
             break;
         default:
             qemuReportError(VIR_ERR_INTERNAL_ERROR,
@@ -5694,6 +5698,8 @@ endjob:
 cleanup:
     virDomainDefFree(vmdef);
     virDomainDeviceDefFree(dev);
+    if (free_dev_copy)
+        virDomainDeviceDefFree(dev_copy);
     if (vm)
         virDomainObjUnlock(vm);
     qemuDriverUnlock(driver);
-- 
1.7.3.4




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