Re: [libvirt] [PATCH] qdev: DEVICE_DELETED event
[adding libvirt] On 03/06/2013 07:52 AM, Paolo Bonzini wrote:
Il 06/03/2013 15:44, Eric Blake ha scritto:
Question - if libvirt misses the event (for example, if libvirtd requests a remove, but then gets restarted, and the event arrives before libvirtd is back up), is there a way to poll whether the the removal has completed? The event is great to minimize polling overhead in the common case, but we generally provide this sort of information via a pollable interface at the same time.
Yes, you can use qom-list on /machine/peripheral.
Which means libvirt should be patched to use qom-list right now, even before this event makes it in, in order to avoid its current bug of reusing a device id before the deletion has completed. Adding the event is still useful, as polling is never nice; and we already know how to make libvirt do conditional code based on whether query-events shows that the event has been added to minimize polling where possible. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
Eric Blake <eblake@redhat.com> writes:
[adding libvirt]
On 03/06/2013 07:52 AM, Paolo Bonzini wrote:
Il 06/03/2013 15:44, Eric Blake ha scritto:
Question - if libvirt misses the event (for example, if libvirtd requests a remove, but then gets restarted, and the event arrives before libvirtd is back up), is there a way to poll whether the the removal has completed? The event is great to minimize polling overhead in the common case, but we generally provide this sort of information via a pollable interface at the same time.
General rule: no event without a way to poll.
Yes, you can use qom-list on /machine/peripheral.
Which means libvirt should be patched to use qom-list right now, even before this event makes it in, in order to avoid its current bug of reusing a device id before the deletion has completed. Adding the event is still useful, as polling is never nice; and we already know how to make libvirt do conditional code based on whether query-events shows that the event has been added to minimize polling where possible.
Yes.
participants (2)
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Eric Blake -
Markus Armbruster