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

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Message-Id: <200710151333.21078.borntraeger@de.ibm.com>
Date:	Mon, 15 Oct 2007 13:33:20 +0200
From:	Christian Borntraeger <borntraeger@...ibm.com>
To:	Avi Kivity <avi@...ranet.com>
Cc:	Laurent Vivier <Laurent.Vivier@...l.net>,
	Ingo Molnar <mingo@...e.hu>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [RESEND 2][PATCH 4/4] Modify KVM to update guest time	accounting.

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.

Christian
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