Re: [PATCH] Device{Attach, Detach}: Document S4 limitations

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 04/30/2014 07:55 AM, Michal Privoznik wrote:
> https://bugzilla.redhat.com/show_bug.cgi?id=808463
> 
> Well, libvirt doesn't distinguish between domain poweroff and
> hibernation (S4). It's hard to differentiate these two on a real
> machine anyway. As a result, any device that is hot(un-)plugged is
> lost (appears again) when domain is started again as from our POV
> it is a fresh cold boot. Instead of doing anything wise here, we
> should just document this as known limitation.

Umm, doesn't qemu give us a different event when a guest stops due to S4
than when it stops due to power off?  Yeah, we don't do a good job of
tracking that a guest is in S4 (since the qemu process no longer
exists), but that's something that could be improved.

> 
> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
> ---
>  src/libvirt.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/src/libvirt.c b/src/libvirt.c
> index b6c99c5..20297eb 100644
> --- a/src/libvirt.c
> +++ b/src/libvirt.c
> @@ -10319,6 +10319,9 @@ virNodeGetSecurityModel(virConnectPtr conn, virSecurityModelPtr secmodel)
>   * in an existing CDROM/Floppy device, however, applications are
>   * recommended to use the virDomainUpdateDeviceFlag method instead.
>   *
> + * Be aware that a device that is hotplugged may disappear if
> + * domain resumes from the S4 state (also known as hibernation).

Maybe be a bit more positive:

Be aware that hotplug changes might not persist across a domain going
into S4 state (also known as hibernation) unless you also modify the
persistent domain definition.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

Attachment: signature.asc
Description: OpenPGP digital signature

--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list

[Index of Archives]     [Virt Tools]     [Libvirt Users]     [Lib OS Info]     [Fedora Users]     [Fedora Desktop]     [Fedora SELinux]     [Big List of Linux Books]     [Yosemite News]     [KDE Users]     [Fedora Tools]