After calling qemuAgentClose(), it is still possible for the QEMU Agent I/O event callback to get invoked. This will trigger an agent error because mon->fd has been set to -1 at this point. Then vm->privateData->agentError is always 'true' except that restart libvirtd or restart qemu-guest-agent process in guest. Silently ignore the case where mon->fd is -1, likewise for mon->watch being zero. Signed-off-by: Wang Yechao <wang.yechao255(a)zte.com.cn&gt; --- v1 patch: https://www.redhat.com/archives/libvir-list/2018-September/msg01382.html Changes in v2: - do not set agentError, let agent state as disconnected instead of error. --- src/qemu/qemu_agent.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_agent.c b/src/qemu/qemu_agent.c index 97ad0e7..d842b0e 100644 --- a/src/qemu/qemu_agent.c +++ b/src/qemu/qemu_agent.c @@ -530,6 +530,9 @@ static void qemuAgentUpdateWatch(qemuAgentPtr mon) VIR_EVENT_HANDLE_HANGUP | VIR_EVENT_HANDLE_ERROR; + if (!mon->watch) + return; + if (mon->lastError.code == VIR_ERR_OK) { events |= VIR_EVENT_HANDLE_READABLE; @@ -555,6 +558,12 @@ qemuAgentIO(int watch, int fd, int events, void *opaque) VIR_DEBUG("Agent %p I/O on watch %d fd %d events %d", mon, watch, fd, events); #endif + if (mon->fd == -1 || mon->watch == 0) { + virObjectUnlock(mon); + virObjectUnref(mon); + return; + } + if (mon->fd != fd || mon->watch != watch) { if (events & (VIR_EVENT_HANDLE_HANGUP | VIR_EVENT_HANDLE_ERROR)) eof = true; @@ -788,8 +797,10 @@ void qemuAgentClose(qemuAgentPtr mon) virObjectLock(mon); if (mon->fd >= 0) { - if (mon->watch) + if (mon->watch) { virEventRemoveHandle(mon->watch); + mon->watch = 0; + } VIR_FORCE_CLOSE(mon->fd); } -- 1.8.3.1