Subject: Re: [patch] KVM: T60 resume fix

From: Ingo Molnar <[email-masked]>
Date: Mon, 5 Mar 2007 09:22:51 +0100

* Avi Kivity <[email-masked]> wrote:

> > my T60 laptop does not resume correctly due to KVM attempting to 
> > send an IPI to a CPU that might be down (or not up yet). (Doing so 
> > also triggers the send_IPI_mask_bitmask() warning in 
> > arch/i386/kernel/smp.c, line 732.)
> >
> >with this fix applied my laptop does not hang during resume.
> >
> >[ KVM will have to disable/enable virtualization on the CPU itself 
> >  that goes down / comes up, not via an IPI sent from the requesting
> > CPU. ]

> That is already CPU_ONLINE in my tree (and in the pull request sent to 
> Linus a couple of days ago).

that solves the resume problem - but doesnt solve the CPU_DEAD issue of 
sending an IPI to an already offline CPU. Might be a better idea to do 
it in CPU_DOWN_PREPARE? (and then to also add a CPU_DOWN_FAILED branch?)

	Ingo