Enabling TOPOEXT is always allowed, but it can't be enabled blindly by "-cpu host" because it may make guests crash if the rest of the cache topology information isn't provided or isn't consistent.
This addresses the bug reported at: https://bugzilla.redhat.com/show_bug.cgi?id=1613277 Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> Message-Id: <20180809221852.15285-1-ehabk...@redhat.com> Tested-by: Richard W.M. Jones <rjo...@redhat.com> Reviewed-by: Babu Moger <babu.mo...@amd.com> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> --- target/i386/cpu.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 52a77a7d08..4e4fe8fa8b 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -849,6 +849,12 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { }, .cpuid_eax = 0x80000001, .cpuid_reg = R_ECX, .tcg_features = TCG_EXT3_FEATURES, + /* + * TOPOEXT is always allowed but can't be enabled blindly by + * "-cpu host", as it requires consistent cache topology info + * to be provided so it doesn't confuse guests. + */ + .no_autoenable_flags = CPUID_EXT3_TOPOEXT, }, [FEAT_C000_0001_EDX] = { .feat_names = { -- 2.18.0.rc1.1.g3f1ff2140
