On Tue, 10 Sep 2013 17:48:59 -0300 Eduardo Habkost <ehabk...@redhat.com> wrote:
> There's no Intel CPU with family=6,model=2, and Linux and Windows guests > disable SEP when seeing that combination due to Pentium Pro erratum #82. > > In addition to just having SEP ignored by guests, Skype (and maybe other > applications) runs sysenter directly without passing through ntdll on > Windows, and crashes because Windows ignored the SEP CPUID bit. > > So, having model > 2 is a better default on qemu64 and qemu32 for two > reasons: making SEP really available for guests, and avoiding crashing > applications that work on bare metal. > > model=3 would fix the problem, but it causes CPU enumeration problems > for Windows guests[1]. So this patch sets model=6, that matches "Athlon > (PM core)" on AMD and "P2 with on-die L2 cache" on Intel and it allows > Windows to use all CPUs as well as fixing sysenter. > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=508623 > > Cc: Andrea Arcangeli <aarca...@redhat.com> > Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> > --- > include/hw/i386/pc.h | 8 ++++++++ > target-i386/cpu.c | 4 ++-- > 2 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h > index 7fb04d8..195e962 100644 > --- a/include/hw/i386/pc.h > +++ b/include/hw/i386/pc.h > @@ -258,6 +258,14 @@ int e820_add_entry(uint64_t, uint64_t, uint32_t); > .driver = TYPE_X86_CPU,\ > .property = "pmu",\ > .value = "on",\ > + },{\ > + .driver = "qemu64-" TYPE_X86_CPU,\ > + .property = "model",\ > + .value = stringify(2),\ > + },{\ > + .driver = "qemu32-" TYPE_X86_CPU,\ > + .property = "model",\ > + .value = stringify(3),\ > } > > #define PC_COMPAT_1_4 \ > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > index c36345e..36cfbce 100644 > --- a/target-i386/cpu.c > +++ b/target-i386/cpu.c > @@ -544,7 +544,7 @@ static x86_def_t builtin_x86_defs[] = { > .level = 4, > .vendor = CPUID_VENDOR_AMD, > .family = 6, > - .model = 2, > + .model = 6, > .stepping = 3, > .features[FEAT_1_EDX] = > PPRO_FEATURES | > @@ -647,7 +647,7 @@ static x86_def_t builtin_x86_defs[] = { > .level = 4, > .vendor = CPUID_VENDOR_INTEL, > .family = 6, > - .model = 3, > + .model = 6, > .stepping = 3, > .features[FEAT_1_EDX] = > PPRO_FEATURES, Reviewed-By: Igor Mammedov <imamm...@redhat.com>
