From: Eric Blake <eblake@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>,
Michal Privoznik <mprivozn@redhat.com>
Cc: libvir-list@redhat.com, qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [libvirt] [PATCHv2 libvirt] qemu: Issue rtc-reset-reinjection command after guest-set-time
Date: Tue, 19 Aug 2014 11:00:26 -0600 [thread overview]
Message-ID: <53F382AA.5020405@redhat.com> (raw)
In-Reply-To: <20140819165713.GA4488@amt.cnet>
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On 08/19/2014 10:57 AM, Marcelo Tosatti wrote:
>
> rtc-reset-reinjection has been introduced because certain Windows
> versions will advance the guest system time (via rtc interrupt
> reinjection).
>
> So if libvirt adjusts the guest system time via guest-set-time,
> allowing rtc interrupt reinjection to compensate for lost time,
> as well, will cause an incorrect guest system time.
>
> So you should always use the
>
> guest-set-time
> rtc-reset-reinjection
>
> pair.
But is that true both for the 'guest-set-time' no-arg case (which tells
the guest to read the current RTC and update in-memory time
accordingly), as well as the 'guest-set-time with time argument' case
(which tells the guest to forcefully set in-memory time, then write that
time back to the RTC)?
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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next prev parent reply other threads:[~2014-08-19 17:00 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <075846faf30f2244fbaaf2c9f47cbae58a9524db.1408004697.git.mprivozn@redhat.com>
[not found] ` <53F21B82.4050006@redhat.com>
2014-08-18 16:29 ` [Qemu-devel] [libvirt] [PATCHv2 libvirt] qemu: Issue rtc-reset-reinjection command after guest-set-time Michal Privoznik
2014-08-19 16:57 ` Marcelo Tosatti
2014-08-19 17:00 ` Eric Blake [this message]
2014-08-19 17:23 ` Marcelo Tosatti
2014-08-20 8:11 ` Michal Privoznik
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