Re: [libvirt] [PATCH] bhyve: implement domainShutdown

On 03/29/2016 08:24 AM, Daniel P. Berrange wrote: >On Mon, Mar 28, 2016 at 10:27:18AM +0300, Roman Bogorodskiy wrote: >>Bhyve supports ACPI shutdown by issuing SIGTERM signal to the bhyve >>process. Add the bhyveDomainShutdown() function and >>virBhyveProcessShutdown() helper function that just sends SIGTERM to >>VM's bhyve process. If a guest supports ACPI shutdown then process >>will be terminated and this event will be noticed by the bhyve monitor >>code that will handle setting proper status and clean up VM's resources. >> >>Also, remove a warning in domainDestroy in case if >>virProcessKillPainfully() returns 1, meaning that it killed process >>using SIGKILL. This behavior should be expected when using 'destroy'. >Hmm, so destroy is supposed to be equivalent to physically removing >the power plug. The existing code is calling virProcessShutdownPainfully >which starts by sending SIGTERM and then switches to SIGKILL. So this >means that your virDomainDestroy implementation is mistakenly trying todo >a graceful shutdown initially and then switching to hard shutdown after a >bit of a delay. For context - the qemu driver does this for destroy as well. I think at least one of the reasons is to allow the qemu process to flush the buffers for the disk image files. I recall this was causing some amount of pain for ovirt (or maybe someone else, I forget)

>Has bhyve always used SIGTERM to trigger ACPI shutdown, or is this a >recent addition ? I would tend to suggest we need to go straight to >SIGKILL for virDomainDestroy to avoid doing ACPI shutdown when we don't >want it. > >It is kind of a shame they used SIGTERM for triggering ACPI imho but >oh well. Yes, it means there is no way to implement a "clean power off" (which would give bhyve the chance to clean up some critical things before pulling the plug).