On 12/19/2011 06:34 PM, Jan Kiszka wrote:
On 2011-12-20 01:31, Anthony Liguori wrote:
On 12/19/2011 05:45 PM, Jan Kiszka wrote:
On 2011-12-19 23:21, Anthony Liguori wrote:
On 12/15/2011 06:33 AM, Jan Kiszka wrote:
To enable migration between accelerated and non-accelerated APIC
models,
we will need to handle the timer saving and restoring specially and can
no longer rely on the automatics of VMSTATE_TIMER. Specifically,
accelerated model will not start any QEMUTimer.
This patch therefore factors out the generic bits into apic_next_timer
and introduces a post-load callback that can be implemented differently
by both models.
Signed-off-by: Jan Kiszka<jan.kiszka@xxxxxxxxxxx>
So you basically want the timer to be a dummy field for the in-kernel
apic?
Can you fix this up in a pre-save routine (put QEMUTimer into a state
where there isn't an event pending)?
It is not a dummy field, it contains the proper state in both cases. We
just need to convert it to an open-coded state to avoid the QEMUTimer
restoration magic in the in-kernel case (where there must be no
QEMUTimer).
So the state gets fed into the kernel instead of userspace?
Nope. It's kept for eventual use by a user space model.
I think you misunderstood my comments.
When you are using the in-kernel APIC, the is no implementation for the
post_load hook. As far as I can tell, the state isn't used.
I know it's used by the user space model but from what I can tell, the value is
essentially sync with the in-kernel APIC almost immediately as it happens during
KVM_RUN.
So it's a QEMUTimer in the userspace model, but it's just an integer when used
in the in-kernel APIC as the timer never fires. It is just saved/restored from
and to the kernel.
Is this correct?
Regards,
Anthony Liguori
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