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i386: Don't automatically enable FEAT_KVM_HINTS bits

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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 <pbonzini@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20180410211534.26079-1-ehabkost@redhat.com>
Tested-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This commit is contained in:
Eduardo Habkost 2018-04-10 18:15:34 -03:00
parent 042f6a31af
commit 0d914f39a7
1 changed files with 9 additions and 1 deletions
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10
target/i386/cpu.c
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@ -295,6 +295,8 @@ typedef struct FeatureWordInfo {
uint32_t tcg_features; /* Feature flags supported by TCG */ uint32_t tcg_features; /* Feature flags supported by TCG */
uint32_t unmigratable_flags; /* Feature flags known to be unmigratable */ uint32_t unmigratable_flags; /* Feature flags known to be unmigratable */
uint32_t migratable_flags; /* Feature flags known to be migratable */ 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; } FeatureWordInfo;
static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { 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, .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EDX,
.tcg_features = TCG_KVM_FEATURES, .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_HYPERV_EAX] = {
.feat_names = { .feat_names = {
@ -4062,7 +4069,8 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
*/ */
env->features[w] |= env->features[w] |=
x86_cpu_get_supported_feature_word(w, cpu->migratable) & x86_cpu_get_supported_feature_word(w, cpu->migratable) &
~env->user_features[w]; ~env->user_features[w] & \
~feature_word_info[w].no_autoenable_flags;
} }
} }