Re: [libvirt] [PATCHv2 06/14] Fix vmdef usage while in monitor in qemuDomainHotplugVcpus

Exit the monitor right after we've done with it to get the virDomainObjPtr lock back, otherwise we might be accessing vm->def while it's being cleaned up by qemuProcessStop. If the domain crashed while we were in the monitor, exit early instead of changing vm->def which is now the persistent definition. --- src/qemu/qemu_driver.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index f7c9219..1275ba4 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -4367,7 +4367,7 @@ static int qemuDomainHotplugVcpus(virQEMUDriverPtr driver, if (rc == 0) goto unsupported; if (rc < 0) - goto cleanup; + goto exit_monitor; vcpus++; } @@ -4378,7 +4378,7 @@ static int qemuDomainHotplugVcpus(virQEMUDriverPtr driver, if (rc == 0) goto unsupported; if (rc < 0) - goto cleanup; + goto exit_monitor; vcpus--; } @@ -4395,6 +4395,10 @@ static int qemuDomainHotplugVcpus(virQEMUDriverPtr driver, * fatal */ if ((ncpupids = qemuMonitorGetCPUInfo(priv->mon, &cpupids)) <= 0) { virResetLastError(); + goto exit_monitor; + } + if (qemuDomainObjExitMonitor(driver, vm) < 0) { + ret = -1; goto cleanup; } @@ -4515,10 +4519,10 @@ static int qemuDomainHotplugVcpus(virQEMUDriverPtr driver, cpupids = NULL; cleanup: - qemuDomainObjExitMonitor(driver, vm); - vm->def->vcpus = vcpus; VIR_FREE(cpupids); VIR_FREE(mem_mask); + if (virDomainObjIsActive(vm)) + vm->def->vcpus = vcpus; virDomainAuditVcpu(vm, oldvcpus, nvcpus, "update", rc == 1);

if (cgroup_vcpu) virCgroupFree(&cgroup_vcpu); @@ -4527,6 +4531,8 @@ static int qemuDomainHotplugVcpus(virQEMUDriverPtr driver, unsupported: virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("cannot change vcpu count of this domain")); + exit_monitor: + ignore_value(qemuDomainObjExitMonitor(driver, vm)); goto cleanup; }