From ed04f30927017781f0aa6aa5f9bd734320f4a330 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Tue, 21 Aug 2018 18:53:11 +0200 Subject: [PATCH 4/5] i386: Disable TOPOEXT by default on "-cpu host" RH-Author: Eduardo Habkost Message-id: <20180821185311.27865-1-ehabkost@redhat.com> Patchwork-id: 81903 O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH] i386: Disable TOPOEXT by default on "-cpu host" Bugzilla: 1613277 RH-Acked-by: Paolo Bonzini RH-Acked-by: Igor Mammedov RH-Acked-by: Miroslav Rezanina Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1613277 Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=17980585 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 Message-Id: <20180809221852.15285-1-ehabkost@redhat.com> Tested-by: Richard W.M. Jones Reviewed-by: Babu Moger Signed-off-by: Eduardo Habkost (cherry picked from commit 7210a02c58572b2686a3a8d610c6628f87864aed) Signed-off-by: Eduardo Habkost Signed-off-by: Miroslav Rezanina --- target/i386/cpu.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index eabe4ea..e6ad66c 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -852,6 +852,12 @@ 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 = { -- 1.8.3.1