From: Michael Tokarev <mjt@tls.msk.ru>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Avi Kivity <avi@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Gerd Hoffmann <kraxel@redhat.com>, KVM list <kvm@vger.kernel.org>,
Gleb Natapov <gleb@redhat.com>,
qemu-devel <qemu-devel@nongnu.org>,
qemu-stable <qemu-stable@nongnu.org>
Subject: Re: [PATCH uq/master] kvm: i8254: Finish time conversion fix
Date: Mon, 13 Aug 2012 22:40:31 +0400 [thread overview]
Message-ID: <50294A1F.9070104@msgid.tls.msk.ru> (raw)
In-Reply-To: <502944F9.9070200@siemens.com>
On 13.08.2012 22:18, Jan Kiszka wrote:
> 0cdd3d1444 fixed reading back the counter load time from the kernel
> while assuming the kernel would always update its load time on writing
> the state. That is only true for channel 1, and so pit_get_channel_info
> returned wrong output pin states for high counter values.
>
> Fix this by applying the offset also on kvm_pit_put. For this purpose,
> we cache the clock offset in KVMPITState, only updating it on VM state
> changes or when we write the state while the VM is stopped.
Wug. The fix (consisting of two halves) appears to be quite messy.
Is it a (temporary) workaround or a real solution?
And yes, this second half fixes the reported issue with grub timekeeping,
and should fix the seabios problem as well (so it shouldn't be necessary
to mess with timekeeping in seabios anymore).
Thank you Jan!
/mjt
WARNING: multiple messages have this Message-ID (diff)
From: Michael Tokarev <mjt@tls.msk.ru>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: KVM list <kvm@vger.kernel.org>, Gleb Natapov <gleb@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
qemu-devel <qemu-devel@nongnu.org>,
qemu-stable <qemu-stable@nongnu.org>, Avi Kivity <avi@redhat.com>,
Gerd Hoffmann <kraxel@redhat.com>
Subject: Re: [Qemu-devel] [PATCH uq/master] kvm: i8254: Finish time conversion fix
Date: Mon, 13 Aug 2012 22:40:31 +0400 [thread overview]
Message-ID: <50294A1F.9070104@msgid.tls.msk.ru> (raw)
In-Reply-To: <502944F9.9070200@siemens.com>
On 13.08.2012 22:18, Jan Kiszka wrote:
> 0cdd3d1444 fixed reading back the counter load time from the kernel
> while assuming the kernel would always update its load time on writing
> the state. That is only true for channel 1, and so pit_get_channel_info
> returned wrong output pin states for high counter values.
>
> Fix this by applying the offset also on kvm_pit_put. For this purpose,
> we cache the clock offset in KVMPITState, only updating it on VM state
> changes or when we write the state while the VM is stopped.
Wug. The fix (consisting of two halves) appears to be quite messy.
Is it a (temporary) workaround or a real solution?
And yes, this second half fixes the reported issue with grub timekeeping,
and should fix the seabios problem as well (so it shouldn't be necessary
to mess with timekeeping in seabios anymore).
Thank you Jan!
/mjt
next prev parent reply other threads:[~2012-08-13 18:40 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-09 18:27 TSC in qem[-kvm] 1.1+ and in-kernel irqchip Michael Tokarev
2012-08-09 18:27 ` [Qemu-devel] " Michael Tokarev
2012-08-09 19:06 ` Marcelo Tosatti
2012-08-09 19:06 ` [Qemu-devel] " Marcelo Tosatti
[not found] ` <20120809204748.GA32346@amt.cnet>
2012-08-09 21:36 ` Michael Tokarev
2012-08-09 21:36 ` [Qemu-devel] " Michael Tokarev
2012-08-10 7:33 ` Gleb Natapov
2012-08-10 7:33 ` Gleb Natapov
2012-08-10 9:24 ` Michael Tokarev
2012-08-10 9:24 ` Michael Tokarev
2012-08-12 8:10 ` Gleb Natapov
2012-08-12 8:10 ` [Qemu-devel] " Gleb Natapov
2012-08-12 9:24 ` Michael Tokarev
2012-08-12 9:24 ` [Qemu-devel] " Michael Tokarev
2012-08-13 13:07 ` Jan Kiszka
2012-08-13 13:07 ` [Qemu-devel] " Jan Kiszka
2012-08-13 13:16 ` Michael Tokarev
2012-08-13 13:16 ` Michael Tokarev
2012-08-13 13:41 ` Jan Kiszka
2012-08-13 13:41 ` Jan Kiszka
2012-08-13 18:18 ` [PATCH uq/master] kvm: i8254: Finish time conversion fix Jan Kiszka
2012-08-13 18:18 ` [Qemu-devel] " Jan Kiszka
2012-08-13 18:40 ` Michael Tokarev [this message]
2012-08-13 18:40 ` Michael Tokarev
2012-08-14 7:41 ` Jan Kiszka
2012-08-14 7:41 ` [Qemu-devel] " Jan Kiszka
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