From 0d914f39a77954bf5472b16130aeefe573a068f5 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Tue, 10 Apr 2018 18:15:34 -0300 Subject: [PATCH] i386: Don't automatically enable FEAT_KVM_HINTS bits The assumption in the cpu->max_features code is that anything enabled on GET_SUPPORTED_CPUID should be enabled on "-cpu host". This shouldn't be the case for FEAT_KVM_HINTS. This adds a new FeatureWordInfo::no_autoenable_flags field, that can be used to prevent FEAT_KVM_HINTS bits to be enabled automatically. Reviewed-by: Paolo Bonzini Signed-off-by: Eduardo Habkost Message-Id: <20180410211534.26079-1-ehabkost@redhat.com> Tested-by: Wanpeng Li Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 1a6b082b6f..a20fe26573 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -295,6 +295,8 @@ typedef struct FeatureWordInfo { uint32_t tcg_features; /* Feature flags supported by TCG */ uint32_t unmigratable_flags; /* Feature flags known to be unmigratable */ uint32_t migratable_flags; /* Feature flags known to be migratable */ + /* Features that shouldn't be auto-enabled by "-cpu host" */ + uint32_t no_autoenable_flags; } FeatureWordInfo; static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { @@ -400,6 +402,11 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { }, .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EDX, .tcg_features = TCG_KVM_FEATURES, + /* + * KVM hints aren't auto-enabled by -cpu host, they need to be + * explicitly enabled in the command-line. + */ + .no_autoenable_flags = ~0U, }, [FEAT_HYPERV_EAX] = { .feat_names = { @@ -4062,7 +4069,8 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error **errp) */ env->features[w] |= x86_cpu_get_supported_feature_word(w, cpu->migratable) & - ~env->user_features[w]; + ~env->user_features[w] & \ + ~feature_word_info[w].no_autoenable_flags; } } -- 2.11.4.GIT