Could you tell me the how to handle the virtualized IPI on Xen ??




2013/8/12 Jan Beulich <JBeulich@suse.com>

> >>> On 11.08.13 at 18:22, J Ahn <jeong.seob.ahn@gmail.com> wrote:
> > I am just wondering how to handle the TLB shootdown IPIs in Xen.
> > Specifically, the guest will send the TLB shootdown IPI to remote CPUs if
> > TLB synchronization between CPUs is required.
> >
> > In this case, I guess the hypervisor intervention is required because it
> > needs to route the interrupt to virtual CPUs of corresponding guest.
> > However, Xen seems not to intercept the event because the number of IPIs
> > from Xenperf is very low. Is this right?
> >
> > I checked the number of IPIs is relatively high in guest OS when using
> 'cat
> > /proc/interrupts'.
> > I also checked the system does not invoke the '*invalidate_interrupt*'
> > function located in *'arch/x86/smp.c*'.
> >
> > If there is no need to intervene to deal with that, could anyone explain
> > that how to maintain the consistent view of TLBs in the guest hosted by
> Xen?
> > Otherwise, please let me know the handling TLB shootdown IPI code in Xen.
>
> I'm getting the impression that you simply mix up physical IPIs (as
> used by the hypervisor) and their virtualized counterparts (as used
> by HVM guests).
>
> Jan
>
>