On 30.03.2015 22:38, Eric Blake wrote:
On 03/30/2015 06:07 AM, Michal Privoznik wrote:
The description to both virDomainShutdown() and virDomainShutdownFlags() is quite misleading when it comes to blocking behaviour of these two APIs. Firstly, we support many shutdown methods, from signalizing an ACPI event, through sending a signal to guest agent assisted shutdown. Some of these methods make the API return immediately, while others block the API until domain is actually shut of. And since virDomainShutdown() is
s/of/off/
equivalent to calling virDomainShutdownFlags(0), it's up to each driver which methods to try. So the bare virDomainShutdown() may block or may return immediately at the same time. I know, it's confusing, but at least let users know.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- src/libvirt-domain.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
I don't think this is the right approach. It is okay to block for a small finite amount of time, but if the guest agent really is something that can hang, we should fix that code to return without waiting for the agent response.
The problem is, we can tell if the shutdown qemu-ga command succeeded only when we see the SHUTDOWN event on the domain monitor. The other option is to treat it like we're treating ACPI mode of the API: just send the request and report if the sending succeeded. Don't wait until domain actually shuts down. I can provide a patch. Michal