[libvirt] [RFC 6/7] migrate: hot remove hostdev at perform phase for bond device

[Chen Fan]

For bond device, we can support the migrate, we can simple
to hot remove the device from source side, and after migration
end, we hot add the new device at destination side.

Signed-off-by: Chen Fan <chen.fan.fnst at cn.fujitsu.com>
---
 src/qemu/qemu_driver.c    | 57 +++++++++++++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_migration.c |  7 ++++++
 2 files changed, 64 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 7368145..0ba9e4a 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -12353,6 +12353,58 @@ qemuDomainMigrateBegin3(virDomainPtr domain,
                               cookieout, cookieoutlen, flags);
 }
 
+static int
+qemuDomainRemovePciPassThruDevices(virConnectPtr conn,
+                                   virDomainObjPtr vm)
+{
+    virQEMUDriverPtr driver = conn->privateData;
+    virDomainDeviceDef dev;
+    virDomainDeviceDefPtr dev_copy = NULL;
+    virCapsPtr caps = NULL;
+    int ret = -1;
+    size_t i;
+
+    if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
+        goto cleanup;
+
+    if (!qemuMigrationJobIsActive(vm, QEMU_ASYNC_JOB_MIGRATION_OUT))
+        goto cleanup;
+
+    /* unplug passthrough bond device */
+    for (i = 0; i < vm->def->nhostdevs; i++) {
+        virDomainHostdevDefPtr hostdev = vm->def->hostdevs[i];
+
+        if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
+            hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
+            hostdev->source.subsys.u.pci.backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO &&
+            hostdev->source.subsys.u.pci.device == VIR_DOMAIN_HOSTDEV_PCI_DEVICE_BOND) {
+
+            dev.type = VIR_DOMAIN_DEVICE_HOSTDEV;
+            dev.data.hostdev = hostdev;
+
+            dev_copy = virDomainDeviceDefCopy(&dev, vm->def, caps, driver->xmlopt);
+            if (!dev_copy)
+                goto cleanup;
+
+            if (qemuDomainDetachHostDevice(driver, vm, dev_copy) < 0) {
+                virDomainDeviceDefFree(dev_copy);
+                goto cleanup;
+            }
+
+            virDomainDeviceDefFree(dev_copy);
+            if (qemuDomainUpdateDeviceList(driver, vm, QEMU_ASYNC_JOB_NONE) < 0)
+                goto cleanup;
+        }
+    }
+
+    ret = 0;
+
+ cleanup:
+    virObjectUnref(caps);
+
+    return ret;
+}
+
 static char *
 qemuDomainMigrateBegin3Params(virDomainPtr domain,
                               virTypedParameterPtr params,
@@ -12688,6 +12740,11 @@ qemuDomainMigratePerform3Params(virDomainPtr dom,
         return -1;
     }
 
+    if (qemuDomainRemovePciPassThruDevices(dom->conn, vm) < 0) {
+        qemuDomObjEndAPI(&vm);
+        return -1;
+    }
+
     return qemuMigrationPerform(driver, dom->conn, vm, dom_xml,
                                 dconnuri, uri, graphicsuri, listenAddress,
                                 cookiein, cookieinlen, cookieout, cookieoutlen,
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 611f53a..9ea83df 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -2000,6 +2000,13 @@ qemuMigrationIsAllowed(virQEMUDriverPtr driver, virDomainObjPtr vm,
     forbid = false;
     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_PCI &&
+            hostdev->source.subsys.u.pci.backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO &&
+            hostdev->source.subsys.u.pci.device == VIR_DOMAIN_HOSTDEV_PCI_DEVICE_BOND)
+            continue;
+
         if (hostdev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS ||
             hostdev->source.subsys.type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB) {
             forbid = true;
-- 
1.9.3