Messages in this thread |  | | Date | Tue, 8 Jan 2013 14:46:34 -0500 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [PATCH v5 00/12] x86/microcode: Early load microcode |
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On Thu, Jan 03, 2013 at 09:48:43AM -0800, H. Peter Anvin wrote: > On 01/03/2013 09:44 AM, Konrad Rzeszutek Wilk wrote: > > > >A couple of questions - why the usage of native_[read|write]_msr? I get the > >__native_cpuid variant, but I am not sure I understand why you are using > >the native_* variants. Especially as this code ends up being called on > >Xen and lguest (at least on 64-bit) and probably should go through the > >paravirt interfaces. > > > > For Xen, the early microcode update should be done in the hypervisor launch.
Right. That is the plan. > > However, if you have a more specific flow in mind please clarify.
> Keep in mind Xen is largely a black box to non-Xen developers > (#include <stdrant.h>).
OK. I am trying to figure out whether this usage of native_* for the MSRs was done on purpose - and it sounds like the answer is no. If so - can it be done using the normal 'safe_rdmsr' and 'wrmsr'?
That would allow at least in the case of Xen, to omit a whole bunch of MSR writes/reads during the boot that are not neccessary as we would not trap in the hypervisor - but could use the pvops version of read/write MSR calls to just do a nop.
> > -hpa > > P.S. Since when is lguest 64-bit? Did I miss something?
Oh, I assumed it could do it. > > -- > H. Peter Anvin, Intel Open Source Technology Center > I work for Intel. I don't speak on their behalf. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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