[libvirt] [PATCH 04/11] Fix vm usage after ExitMonitor on device removal

[Ján Tomko]

In the device type-specific functions, exit early
if the domain has disappeared, because the cleanup
should have been done by qemuProcessStop.

In processDeviceDeletedEvent, only save status XML if the domain
is still running and exit early in qemuProcessUpdateDevices
if the domain disappeared.
---
 src/qemu/qemu_driver.c  |  3 ++-
 src/qemu/qemu_hotplug.c | 18 ++++++++++++------
 src/qemu/qemu_process.c |  2 ++
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 99eb7c3..07b061e 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4112,7 +4112,8 @@ processDeviceDeletedEvent(virQEMUDriverPtr driver,
 
     qemuDomainRemoveDevice(driver, vm, &dev);
 
-    if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm) < 0)
+    if (virDomainObjIsActive(vm) &&
+        virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm) < 0)
         VIR_WARN("unable to save domain status after removing device %s",
                  devAlias);
 
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 5b65283..3fcbef3 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -2507,8 +2507,9 @@ qemuDomainRemoveDiskDevice(virQEMUDriverPtr driver,
 
     qemuDomainObjEnterMonitor(driver, vm);
     qemuMonitorDriveDel(priv->mon, drivestr);
-    qemuDomainObjExitMonitor(driver, vm);
     VIR_FREE(drivestr);
+    if (qemuDomainObjExitMonitorAlive(driver, vm) < 0)
+        return -1;
 
     virDomainAuditDisk(vm, disk->src, NULL, "detach", true);
 
@@ -2623,7 +2624,8 @@ qemuDomainRemoveHostDevice(virQEMUDriverPtr driver,
 
         qemuDomainObjEnterMonitor(driver, vm);
         qemuMonitorDriveDel(priv->mon, drivestr);
-        qemuDomainObjExitMonitor(driver, vm);
+        if (qemuDomainObjExitMonitorAlive(driver, vm) < 0)
+            goto cleanup;
     }
 
     event = virDomainEventDeviceRemovedNewFromObj(vm, hostdev->info->alias);
@@ -2717,7 +2719,8 @@ qemuDomainRemoveNetDevice(virQEMUDriverPtr driver,
     if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_NETDEV) &&
         virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE)) {
         if (qemuMonitorRemoveNetdev(priv->mon, hostnet_name) < 0) {
-            qemuDomainObjExitMonitor(driver, vm);
+            if (qemuDomainObjExitMonitorAlive(driver, vm) < 0)
+                goto cleanup;
             virDomainAuditNet(vm, net, NULL, "detach", false);
             goto cleanup;
         }
@@ -2729,12 +2732,14 @@ qemuDomainRemoveNetDevice(virQEMUDriverPtr driver,
                 virReportError(VIR_ERR_OPERATION_FAILED, "%s",
                                _("unable to determine original VLAN"));
             }
-            qemuDomainObjExitMonitor(driver, vm);
+            if (qemuDomainObjExitMonitorAlive(driver, vm) < 0)
+                goto cleanup;
             virDomainAuditNet(vm, net, NULL, "detach", false);
             goto cleanup;
         }
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitorAlive(driver, vm) < 0)
+        goto cleanup;
 
     virDomainAuditNet(vm, net, NULL, "detach", true);
 
@@ -2804,7 +2809,8 @@ qemuDomainRemoveChrDevice(virQEMUDriverPtr driver,
 
     qemuDomainObjEnterMonitor(driver, vm);
     rc = qemuMonitorDetachCharDev(priv->mon, charAlias);
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitorAlive(driver, vm) < 0)
+        goto cleanup;
 
     virDomainAuditChardev(vm, chr, NULL, "detach", rc == 0);
 
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index d683918..d4af85c 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -3519,6 +3519,8 @@ qemuProcessUpdateDevices(virQEMUDriverPtr driver,
             if (!virStringArrayHasString(priv->qemuDevices, *tmp) &&
                 virDomainDefFindDevice(vm->def, *tmp, &dev, false) == 0)
                 qemuDomainRemoveDevice(driver, vm, &dev);
+            if (!virDomainObjIsActive(vm))
+                goto cleanup;
             tmp++;
         }
     }
-- 
2.0.4