[Xen-devel] RE: XEN monitor/mwait patch for AMD SVM

["Boppuri, Navin" <Navin.Boppuri@xxxxxxx>]

:) Point taken! Thank you for considering the request though.

-Navin

> -----Original Message-----
> From: Keir Fraser [mailto:keir.fraser@xxxxxxxxxxxxx]
> Sent: Friday, May 22, 2009 12:19 PM
> To: Boppuri, Navin; xen-devel@xxxxxxxxxxxxxxxxxxx
> Subject: Re: XEN monitor/mwait patch for AMD SVM
> 
> That's firmly in the 'Doctor, it hurts when I...' category I'm afraid. No
> way will I apply this type of patch.
> 
>  -- Keir
> 
> On 22/05/2009 18:10, "Boppuri, Navin" <Navin.Boppuri@xxxxxxx> wrote:
> 
> > Keir,
> >
> > Sorry but the patch is against the latest tip of the xen unstable tree
> > (changeset: 18646).
> >
> > I understand that MWAIT is not mentioned in the whitelist for HVM
> policy.
> > However, one could modify the guest config file and set the cpuid bit
> for
> > monitor/mwait and enable this feature by force. I was able to do just
> this in
> > my test configuration. This patch should cover such mods for cpuid in
> addition
> > to the cpuid policy in libxc.
> >
> > Thank you.
> > -Navin
> >
> >> -----Original Message-----
> >> From: Keir Fraser [mailto:keir.fraser@xxxxxxxxxxxxx]
> >> Sent: Friday, May 22, 2009 11:40 AM
> >> To: Boppuri, Navin; xen-devel@xxxxxxxxxxxxxxxxxxx
> >> Subject: Re: XEN monitor/mwait patch for AMD SVM
> >>
> >> On 22/05/2009 16:23, "Boppuri, Navin" <Navin.Boppuri@xxxxxxx> wrote:
> >>
> >>> This patch clears the monitor/mwait bit in the cpuid intercept code
> for
> >> AMD¹s
> >>> SVM. This is to disallow VM¹s that may try and use the monitor/mwait
> >> feature
> >>> on AMD processors which is currently not supported in XEN.
> >>>
> >>> Signed-off-by: Navin Boppuri <navin.boppuri@xxxxxxx>
> >>
> >> What Xen version is this patch against? We already hide MWAIT from HVM
> >> guests as far as I am aware. See
> >> tools/libxc/xc_cpuid_x86.c:xc_cpuid_hvm_policy(), and note that
> features
> >> are
> >> *whitelisted* and also that MWAIT is *not* mentioned.
> >>
> >> So I think your patch is not needed, and also inappropriate since we
> >> implement CPUID filtering policy in libxc these days.
> >>
> >>  -- Keir
> >>
> >>
> >
> >
> 
> 



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel