[libvirt] [PATCHv3 2/3] Fix vmdef usage after domain crash in monitor on device attach

[Ján Tomko]

https://bugzilla.redhat.com/show_bug.cgi?id=1161024

If the domain crashed while we were in monitor,
we cannot rely on the REALLOC done on live definition,
since vm->def now points to the persistent definition.
Skip adding the attached devices to domain definition
if the domain crashed.

In AttachChrDevice, the chardev was already added to the
live definition and freed by qemuProcessStop in the case
of a crash. Skip the device removal in that case.

Also skip audit if the domain crashed in the meantime.
---
 src/qemu/qemu_hotplug.c | 69 +++++++++++++++++++++++++++++++++++++------------
 1 file changed, 52 insertions(+), 17 deletions(-)

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 32464aa..748fbfe 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -391,7 +391,11 @@ qemuDomainAttachVirtioDiskDevice(virConnectPtr conn,
             memcpy(&disk->info.addr.pci, &guestAddr, sizeof(guestAddr));
         }
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        releaseaddr = false;
+        ret = -1;
+        goto error;
+    }
 
     virDomainAuditDisk(vm, NULL, disk->src, "attach", ret >= 0);
 
@@ -477,7 +481,11 @@ int qemuDomainAttachControllerDevice(virQEMUDriverPtr driver,
                                                  type,
                                                  &controller->info.addr.pci);
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        releaseaddr = false;
+        ret = -1;
+        goto cleanup;
+    }
 
     if (ret == 0) {
         if (controller->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE)
@@ -628,7 +636,10 @@ qemuDomainAttachSCSIDisk(virConnectPtr conn,
             disk->info.addr.drive.unit = driveAddr.unit;
         }
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        ret = -1;
+        goto error;
+    }
 
     virDomainAuditDisk(vm, NULL, disk->src, "attach", ret >= 0);
 
@@ -708,7 +719,10 @@ qemuDomainAttachUSBMassstorageDevice(virConnectPtr conn,
     } else {
         ret = qemuMonitorAddUSBDisk(priv->mon, src);
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        ret = -1;
+        goto error;
+    }
 
     virDomainAuditDisk(vm, NULL, disk->src, "attach", ret >= 0);
 
@@ -1280,7 +1294,8 @@ qemuDomainAttachHostPCIDevice(virQEMUDriverPtr driver,
         qemuDomainObjEnterMonitor(driver, vm);
         ret = qemuMonitorAddDeviceWithFd(priv->mon, devstr,
                                          configfd, configfd_name);
-        qemuDomainObjExitMonitor(driver, vm);
+        if (qemuDomainObjExitMonitor(driver, vm) < 0)
+            goto error;
     } else {
         virDevicePCIAddressPtr guestAddr = &hostdev->info->addr.pci;
         virDevicePCIAddressPtr hostAddr = &hostdev->source.subsys.u.pci.addr;
@@ -1296,7 +1311,8 @@ qemuDomainAttachHostPCIDevice(virQEMUDriverPtr driver,
 
         qemuDomainObjEnterMonitor(driver, vm);
         ret = qemuMonitorAddPCIHostDevice(priv->mon, hostAddr, guestAddr);
-        qemuDomainObjExitMonitor(driver, vm);
+        if (qemuDomainObjExitMonitor(driver, vm) < 0)
+            goto error;
 
         hostdev->info->type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
     }
@@ -1360,12 +1376,11 @@ int qemuDomainAttachRedirdevDevice(virQEMUDriverPtr driver,
         goto error;
 
     qemuDomainObjEnterMonitor(driver, vm);
-    if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE))
-        ret = qemuMonitorAddDevice(priv->mon, devstr);
-    else
+    ret = qemuMonitorAddDevice(priv->mon, devstr);
+
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
         goto error;
 
-    qemuDomainObjExitMonitor(driver, vm);
     virDomainAuditRedirdev(vm, redirdev, "attach", ret == 0);
     if (ret < 0)
         goto error;
@@ -1487,17 +1502,29 @@ int qemuDomainAttachChrDevice(virQEMUDriverPtr driver,
 
     qemuDomainObjEnterMonitor(driver, vm);
     if (qemuMonitorAttachCharDev(priv->mon, charAlias, &chr->source) < 0) {
-        qemuDomainObjExitMonitor(driver, vm);
+        if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+            need_remove = false;
+            ret = -1;
+            goto cleanup;
+        }
         goto audit;
     }
 
     if (devstr && qemuMonitorAddDevice(priv->mon, devstr) < 0) {
         /* detach associated chardev on error */
         qemuMonitorDetachCharDev(priv->mon, charAlias);
-        qemuDomainObjExitMonitor(driver, vm);
+        if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+            need_remove = false;
+            ret = -1;
+            goto cleanup;
+        }
         goto audit;
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        need_remove = false;
+        ret = -1;
+        goto cleanup;
+    }
 
     ret = 0;
  audit:
@@ -1553,7 +1580,10 @@ qemuDomainAttachHostUSBDevice(virQEMUDriverPtr driver,
         ret = qemuMonitorAddUSBDeviceExact(priv->mon,
                                            hostdev->source.subsys.u.usb.bus,
                                            hostdev->source.subsys.u.usb.device);
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        ret = -1;
+        goto cleanup;
+    }
     virDomainAuditHostdev(vm, hostdev, "attach", ret == 0);
     if (ret < 0)
         goto cleanup;
@@ -1656,7 +1686,10 @@ qemuDomainAttachHostSCSIDevice(virConnectPtr conn,
             }
         }
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        ret = -1;
+        goto cleanup;
+    }
 
     virDomainAuditHostdev(vm, hostdev, "attach", ret == 0);
     if (ret < 0)
@@ -1856,7 +1889,8 @@ int qemuDomainChangeNetLinkState(virQEMUDriverPtr driver,
     dev->linkstate = linkstate;
 
  cleanup:
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        return -1;
 
     return ret;
 }
@@ -3641,7 +3675,8 @@ qemuDomainChangeGraphicsPasswords(virQEMUDriverPtr driver,
     }
 
  end_job:
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
  cleanup:
     virObjectUnref(cfg);
     return ret;
-- 
2.0.4