> -----Original Message----- > From: Radim Krčmář [mailto:rkrc...@redhat.com] > Sent: Wednesday, February 28, 2018 12:24 PM > To: Moger, Babu <babu.mo...@amd.com> > Cc: pbonz...@redhat.com; r...@twiddle.net; ehabk...@redhat.com; > mtosa...@redhat.com; qemu-devel@nongnu.org; k...@vger.kernel.org; > p...@polepetko.eu; Hook, Gary <gary.h...@amd.com> > Subject: Re: [PATCH v2 3/5] target/i386: Add support for CPUID_8000_001E > for AMD > > 2018-02-23 21:30-0500, Babu Moger: > > From: Stanislav Lanci <p...@polepetko.eu> > > > > Populate threads/core_id/apic_ids/socket_id when CPUID_EXT3_TOPOEXT > > feature is supported. This is required to support hyperthreading > > feature on AMD CPUS. These are supported via CPUID_8000_001E > extended > > functions. > > > > Signed-off-by: Stanislav Lanci <p...@polepetko.eu> > > Signed-off-by: Babu Moger <babu.mo...@amd.com> > > --- > > target/i386/cpu.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > > index a5a480e..191e850 100644 > > --- a/target/i386/cpu.c > > +++ b/target/i386/cpu.c > > @@ -3666,6 +3666,14 @@ void cpu_x86_cpuid(CPUX86State *env, > uint32_t index, uint32_t count, > > *edx = 0; > > } > > break; > > + case 0x8000001E: > > + if (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_TOPOEXT) { > > + *eax = cpu->apic_id; > > + *ebx = (cs->nr_threads - 1) << 8 | cpu->core_id; > > Do we somewhere assert that AMD cannot have cpu->core_id > 255? > (qemu does allow weird configurations.)
I don't see specific assert on core_id. But, I see that qemu does not allow nr_cores more than 255. Also I see that core_id is iterated based on nr_cores. If you strongly believe we need to add assert here, I will add it. Let me know. > Thanks. > > > + *ecx = cpu->socket_id; > > + *edx = 0; > > + } > > + break; > > case 0xC0000000: > > *eax = env->cpuid_xlevel2; > > *ebx = 0; > > -- > > 1.8.3.1 > >
