[libvirt] [PATCH 7/8] qemu: support updating interface with boot index

[Wang Rui]

QEMU supported to set device's boot index online recently(since QEMU 2.2.0).
This patch implements the interface's boot index update lively.

If PCI address is not specified in the new xml, we can also update boot
index. If boot order is not specified in the new xml, we take it as canceling
boot index. So pass "value":-1 to qmp command("qom-set") to cancel boot index.

Signed-off-by: Wang Rui <moon.wangrui at huawei.com>
Signed-off-by: Zhou Yimin <zhouyimin at huawei.com>
---
 src/qemu/qemu_hotplug.c | 35 ++++++++++++++++++++++++++++++-----
 1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 5eacfce..4c86370 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1814,6 +1814,7 @@ qemuDomainChangeNet(virQEMUDriverPtr driver,
     bool needLinkStateChange = false;
     bool needReplaceDevDef = false;
     bool needBandwidthSet = false;
+    bool needBootIndexChange = false;
     int ret = -1;
 
     if (!devslot || !(olddev = *devslot)) {
@@ -1909,6 +1910,19 @@ qemuDomainChangeNet(virQEMUDriverPtr driver,
         goto cleanup;
     }
 
+    /* If(and olny if) PCI adderss is not specified in the new xml, newdev->info.type
+     * here is NONE. We can copy the old device's PCI address to the new one. We can't
+     * copy olddev->info to newdev->info, because other members in newdev->info(such
+     * as bootIndex) should not be overridden.
+     */
+    if (newdev->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE) {
+        newdev->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
+        newdev->info.addr.pci.domain = olddev->info.addr.pci.domain;
+        newdev->info.addr.pci.bus = olddev->info.addr.pci.bus;
+        newdev->info.addr.pci.slot = olddev->info.addr.pci.slot;
+        newdev->info.addr.pci.function = olddev->info.addr.pci.function;
+    }
+
     /* info: if newdev->info is empty, fill it in from olddev,
      * otherwise verify that it matches - nothing is allowed to
      * change. (There is no helper function to do this, so
@@ -1945,11 +1959,6 @@ qemuDomainChangeNet(virQEMUDriverPtr driver,
                        _("cannot modify network rom file"));
         goto cleanup;
     }
-    if (olddev->info.bootIndex != newdev->info.bootIndex) {
-        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
-                       _("cannot modify network device boot index setting"));
-        goto cleanup;
-    }
     /* (end of device info checks) */
 
     if (STRNEQ_NULLABLE(olddev->filter, newdev->filter) ||
@@ -2101,6 +2110,9 @@ qemuDomainChangeNet(virQEMUDriverPtr driver,
                                  virDomainNetGetActualBandwidth(newdev)))
         needBandwidthSet = true;
 
+    if (olddev->info.bootIndex != newdev->info.bootIndex)
+        needBootIndexChange = true;
+
     /* FINALLY - actually perform the required actions */
 
     if (needReconnect) {
@@ -2141,6 +2153,19 @@ qemuDomainChangeNet(virQEMUDriverPtr driver,
         goto cleanup;
     }
 
+    if (needBootIndexChange) {
+        /* If boot index is to be changed to 0, we can pass "value":-1 to
+           qmp command("qom-set") to cancel boot index. */
+        if (qemuDomainChangeBootIndex(driver, vm, &olddev->info,
+                                      newdev->info.bootIndex ?
+                                      newdev->info.bootIndex : -1) < 0)
+            goto cleanup;
+        /* we successfully switched to the new boot index, and we've
+         * determined that the rest of newdev is equivalent to olddev,
+         * so move newdev into place */
+        needReplaceDevDef = true;
+    }
+
     if (needReplaceDevDef) {
         /* the changes above warrant replacing olddev with newdev in
          * the domain's nets list.
-- 
1.7.12.4