Re: [RESEND 2][PATCH 4/4] Modify KVM to update guest time accounting.

Laurent Vivier
2007-10-15T11:39:22Z

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Christian Borntraeger wrote:
> Am Montag, 15. Oktober 2007 schrieb Avi Kivity:
>> We can clear it a bit later, after local_irq_enable() in __vcpu_run().
>> However we need a nop instruction first because "sti" keeps interrupts
>> disabled for one more instruction.
>
> Ah, I see. The host interrupt behaves different and instead of running the
> interrupt handler, it exits the vmrun on x86? The interrupt handler will be
> called some cycles after the sti?
> That is different to s390. We can run the guest code for a long time and the
> host instruction pointer stays on the sie instruction. That means, we can
> interrupt sie and continue by simply setting the instrution pointer (PSW)
> back to the sie instruction.
>
> Any idea how to make this proper on all architectures? I will have a look.

I think the solution is to have an arch dependent kvm_guest_exit(): empty for
x86, clearing the bit for s390.

Regards,
Laurent
--
---------------- Laurent.Vivier@bull.net -----------------
"Given enough eyeballs, all bugs are shallow" E. S. Raymond

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