[libvirt] [PATCHv2 05/14] 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.
---
 src/qemu/qemu_hotplug.c | 54 ++++++++++++++++++++++++++++++++-----------------
 1 file changed, 36 insertions(+), 18 deletions(-)

diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index c480dcd..a4e4d6b 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -391,7 +391,10 @@ qemuDomainAttachVirtioDiskDevice(virConnectPtr conn,
             memcpy(&disk->info.addr.pci, &guestAddr, sizeof(guestAddr));
         }
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        releaseaddr = false;
+        ret = -1;
+    }
 
     virDomainAuditDisk(vm, NULL, disk->src, "attach", ret >= 0);
 
@@ -477,7 +480,10 @@ int qemuDomainAttachControllerDevice(virQEMUDriverPtr driver,
                                                  type,
                                                  &controller->info.addr.pci);
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        releaseaddr = false;
+        ret = -1;
+    }
 
     if (ret == 0) {
         if (controller->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE)
@@ -628,7 +634,8 @@ qemuDomainAttachSCSIDisk(virConnectPtr conn,
             disk->info.addr.drive.unit = driveAddr.unit;
         }
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
 
     virDomainAuditDisk(vm, NULL, disk->src, "attach", ret >= 0);
 
@@ -708,7 +715,8 @@ qemuDomainAttachUSBMassstorageDevice(virConnectPtr conn,
     } else {
         ret = qemuMonitorAddUSBDisk(priv->mon, src);
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
 
     virDomainAuditDisk(vm, NULL, disk->src, "attach", ret >= 0);
 
@@ -1272,7 +1280,8 @@ qemuDomainAttachHostPCIDevice(virQEMUDriverPtr driver,
         qemuDomainObjEnterMonitor(driver, vm);
         ret = qemuMonitorAddDeviceWithFd(priv->mon, devstr,
                                          configfd, configfd_name);
-        qemuDomainObjExitMonitor(driver, vm);
+        if (qemuDomainObjExitMonitor(driver, vm) < 0)
+            ret = -1;
     } else {
         virDevicePCIAddressPtr guestAddr = &hostdev->info->addr.pci;
         virDevicePCIAddressPtr hostAddr = &hostdev->source.subsys.u.pci.addr;
@@ -1288,7 +1297,8 @@ qemuDomainAttachHostPCIDevice(virQEMUDriverPtr driver,
 
         qemuDomainObjEnterMonitor(driver, vm);
         ret = qemuMonitorAddPCIHostDevice(priv->mon, hostAddr, guestAddr);
-        qemuDomainObjExitMonitor(driver, vm);
+        if (qemuDomainObjExitMonitor(driver, vm) < 0)
+            ret = -1;
 
         hostdev->info->type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI;
     }
@@ -1352,12 +1362,11 @@ int qemuDomainAttachRedirdevDevice(virQEMUDriverPtr driver,
         goto error;
 
     qemuDomainObjEnterMonitor(driver, vm);
-    if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE))
-        ret = qemuMonitorAddDevice(priv->mon, devstr);
-    else
-        goto error;
+    ret = qemuMonitorAddDevice(priv->mon, devstr);
+
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
 
-    qemuDomainObjExitMonitor(driver, vm);
     virDomainAuditRedirdev(vm, redirdev, "attach", ret == 0);
     if (ret < 0)
         goto error;
@@ -1479,17 +1488,22 @@ 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;
         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;
+        goto audit;
+    }
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        need_remove = false;
         goto audit;
     }
-    qemuDomainObjExitMonitor(driver, vm);
 
     ret = 0;
  audit:
@@ -1545,7 +1559,8 @@ 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;
     virDomainAuditHostdev(vm, hostdev, "attach", ret == 0);
     if (ret < 0)
         goto cleanup;
@@ -1648,7 +1663,8 @@ qemuDomainAttachHostSCSIDevice(virConnectPtr conn,
             }
         }
     }
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
 
     virDomainAuditHostdev(vm, hostdev, "attach", ret == 0);
     if (ret < 0)
@@ -1848,7 +1864,8 @@ int qemuDomainChangeNetLinkState(virQEMUDriverPtr driver,
     dev->linkstate = linkstate;
 
  cleanup:
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        return -1;
 
     return ret;
 }
@@ -3633,7 +3650,8 @@ qemuDomainChangeGraphicsPasswords(virQEMUDriverPtr driver,
     }
 
  end_job:
-    qemuDomainObjExitMonitor(driver, vm);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
  cleanup:
     virObjectUnref(cfg);
     return ret;
-- 
2.0.4