From 584c13f3560fca894c568db39b81a856db1387cb Mon Sep 17 00:00:00 2001 From: Jiri Denemark Date: Fri, 3 Dec 2010 10:48:31 +0100 Subject: [PATCH] qemu: Fix a possible deadlock in p2p migration Two more calls to remote libvirtd have to be surrounded by qemuDomainObjEnterRemoteWithDriver() and qemuDomainObjExitRemoteWithDriver() to prevent possible deadlock between two communicating libvirt daemons. See commit f0c8e1cb3774d6f09e2681ca1988bf235a343007 for further details. --- src/qemu/qemu_driver.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 1b86b5e18e..f5164e1327 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -11625,24 +11625,38 @@ static int doPeer2PeerMigrate(virDomainPtr dom, int ret = -1; virConnectPtr dconn = NULL; char *dom_xml; + bool p2p; /* the order of operations is important here; we make sure the * destination side is completely setup before we touch the source */ + qemuDomainObjEnterRemoteWithDriver(driver, vm); dconn = virConnectOpen(uri); + qemuDomainObjExitRemoteWithDriver(driver, vm); if (dconn == NULL) { qemuReportError(VIR_ERR_OPERATION_FAILED, _("Failed to connect to remote libvirt URI %s"), uri); return -1; } - if (!VIR_DRV_SUPPORTS_FEATURE(dconn->driver, dconn, - VIR_DRV_FEATURE_MIGRATION_P2P)) { + + qemuDomainObjEnterRemoteWithDriver(driver, vm); + p2p = VIR_DRV_SUPPORTS_FEATURE(dconn->driver, dconn, + VIR_DRV_FEATURE_MIGRATION_P2P); + qemuDomainObjExitRemoteWithDriver(driver, vm); + if (!p2p) { qemuReportError(VIR_ERR_OPERATION_FAILED, "%s", _("Destination libvirt does not support peer-to-peer migration protocol")); goto cleanup; } + /* domain may have been stopped while we were talking to remote daemon */ + if (!virDomainObjIsActive(vm)) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("guest unexpectedly quit")); + goto cleanup; + } + dom_xml = qemudVMDumpXML(driver, vm, VIR_DOMAIN_XML_SECURE | VIR_DOMAIN_XML_UPDATE_CPU); -- 2.47.2