Re: [PATCH v3 4/8] target/i386/intel-pt: print special message for INTEL_PT_ADDR_RANGES_NUM

[Xiaoyao Li]

On 12/9/2022 2:43 PM, Chenyi Qiang wrote:
> On 12/8/2022 2:25 PM, Xiaoyao Li wrote:
> > Bit[2:0] of CPUID.14H_01H:EAX stands as a whole for the number of INTEL
> > PT ADDR RANGES. For unsupported value that exceeds what KVM reports,
> > report it as a whole in mark_unavailable_features() as well.
>
> Maybe this patch can be put before 3/8.

patch 3 introduces the logic to check bit 2:0 of CPUID leaf 14_1 as 
whole. So it's better to be after patch 3.

+            /* Bits 2:0 are as a whole to represent INTEL_PT_ADDR_RANGES */
+            if ((requested_features & INTEL_PT_ADDR_RANGES_NUM_MASK) >
+                (host_feat & INTEL_PT_ADDR_RANGES_NUM_MASK)) {
+                unavailable_features |= requested_features &
+                                        INTEL_PT_ADDR_RANGES_NUM_MASK;

> > Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
> > ---
> >   target/i386/cpu.c | 9 ++++++++-
> >   1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> > index 65c6f8ae771a..4d7beccc0af7 100644
> > --- a/target/i386/cpu.c
> > +++ b/target/i386/cpu.c
> > @@ -4387,7 +4387,14 @@ static void mark_unavailable_features(X86CPU *cpu, 
> > FeatureWord w, uint64_t mask,
> >           return;
> >       }
> >   
> > -    for (i = 0; i < 64; ++i) {
> > +    if ((w == FEAT_14_1_EAX) && (mask & INTEL_PT_ADDR_RANGES_NUM_MASK)) {
> > +        warn_report("%s: CPUID.14H_01H:EAX [bit 2:0]", verbose_prefix);
> > +        i = 3;
> > +    } else {
> > +        i = 0;
> > +    }
> > +
> > +    for (; i < 64; ++i) {
> >           if ((1ULL << i) & mask) {
> >               g_autofree char *feat_word_str = feature_word_description(f, i);
> >               warn_report("%s: %s%s%s [bit %d]",