Re: [Qemu-devel] [PATCH] i386/cpu: name new CPUID bits

[Andre Przywara]

On 10/18/12 18:33, Eduardo Habkost wrote:
> On Wed, Oct 17, 2012 at 11:17:26PM +0200, Andre Przywara wrote:
> > Update QEMU's knowledge of CPUID bit names. This allows to
> > enable/disable those new features on QEMU's command line when
> > using KVM and prepares future feature enablement in QEMU.
...
> > @@ -79,10 +79,10 @@ static const char *ext3_feature_name[] = {
> >       "lahf_lm" /* AMD LahfSahf */, "cmp_legacy", "svm", "extapic" /* AMD 
> > ExtApicSpace */,
> >       "cr8legacy" /* AMD AltMovCr8 */, "abm", "sse4a", "misalignsse",
> >       "3dnowprefetch", "osvw", "ibs", "xop",
> > -    "skinit", "wdt", NULL, NULL,
> > -    "fma4", NULL, "cvt16", "nodeid_msr",
> > -    NULL, NULL, NULL, NULL,
> > -    NULL, NULL, NULL, NULL,
> > +    "skinit", "wdt", NULL, "lwp",
> > +    "fma4", "tce", NULL, "nodeid_msr",
>
> You removed cvt16, here.

On purpose, cvt16 is dead. It seems to have been advertised in the 
documentation for some time, but later disappeared. The respective 
instructions are now reported via the F16C flag in the Intel leaf.

If you want to know more, I can dig deeper and ask some people. But the 
bit is now "reserved" and was never '1' in any silicon. (And was 
introduced by me into QEMU :-(

> All the rest of the flags look OK to me.

Thanks.

Regards,
Andre.