From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47648) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f87Ag-0001fW-4c for qemu-devel@nongnu.org; Mon, 16 Apr 2018 12:40:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f87Af-0006qf-4W for qemu-devel@nongnu.org; Mon, 16 Apr 2018 12:40:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41748) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f87Ae-0006qG-Up for qemu-devel@nongnu.org; Mon, 16 Apr 2018 12:40:01 -0400 From: Eduardo Habkost Date: Mon, 16 Apr 2018 13:39:53 -0300 Message-Id: <20180416163953.31188-2-ehabkost@redhat.com> In-Reply-To: <20180416163953.31188-1-ehabkost@redhat.com> References: <20180416163953.31188-1-ehabkost@redhat.com> Subject: [Qemu-devel] [PULL 1/1] i386: Don't automatically enable FEAT_KVM_HINTS bits List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Paolo Bonzini , qemu-devel@nongnu.org, Richard Henderson , Eduardo Habkost 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; } } -- 2.14.3