From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55047) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XOphn-0000mQ-Hu for qemu-devel@nongnu.org; Tue, 02 Sep 2014 11:09:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XOphe-0001TJ-5o for qemu-devel@nongnu.org; Tue, 02 Sep 2014 11:09:11 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:55174) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XOphe-0001T7-0D for qemu-devel@nongnu.org; Tue, 02 Sep 2014 11:09:02 -0400 Received: from /spool/local by e32.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 2 Sep 2014 09:09:01 -0600 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable From: Michael Roth In-Reply-To: <20140821201438.GA12310@thinpad.lan.raisama.net> References: <1408566612-10367-1-git-send-email-ehabkost@redhat.com> <20140821201438.GA12310@thinpad.lan.raisama.net> Message-ID: <20140902150856.16792.44698@loki> Date: Tue, 02 Sep 2014 10:08:56 -0500 Subject: Re: [Qemu-devel] [Qemu-stable] [PATCH] target-i386: Support migratable=no properly List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost , qemu-devel@nongnu.org, qemu-stable@nongnu.org, =?utf-8?q?Andreas_F=C3=A4rber?= Cc: Igor Mammedov , Marcelo Tosatti , Paolo Bonzini Quoting Eduardo Habkost (2014-08-21 15:14:38) > Forgot to add qemu-devel to "To:". Adding it. > = > On Wed, Aug 20, 2014 at 05:30:12PM -0300, Eduardo Habkost wrote: > > When the "migratable" property was implemented, the behavior was tested > > by changing the default on the code, but actually using the option on > > the command-line (e.g. "-cpu host,migratable=3Dfalse") doesn't work as > > expected. This is a regression for a common use case of "-cpu host", > > which is to enable features that are supported by the host CPU + kernel > > before feature-specific code is added to QEMU. > > = > > Fix this by initializing the feature words for "-cpu host" on > > x86_cpu_parse_featurestr(), right after parsing the CPU options. > > = > > Signed-off-by: Eduardo Habkost Ping for stable 2.1.1, freeze is Wednesday. Reviewed-by: Michael Roth > > --- > > I was considering a more complex (but less hacky) fix, by introducing an > > enum FeatureBit { OFF, ON, HOST }, making FeatureWord a 32-element > > FeatureBit array, and initializing the actual feature bits on > > x86_cpu_realizefn(). But as this is a patch for qemu-stable, I kept the > > fix as simple as possible. > > --- > > target-i386/cpu-qom.h | 1 + > > target-i386/cpu.c | 17 ++++++++++++----- > > 2 files changed, 13 insertions(+), 5 deletions(-) > > = > > diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h > > index 71a1b97..7755466 100644 > > --- a/target-i386/cpu-qom.h > > +++ b/target-i386/cpu-qom.h > > @@ -92,6 +92,7 @@ typedef struct X86CPU { > > bool enforce_cpuid; > > bool expose_kvm; > > bool migratable; > > + bool host_features; > > = > > /* if true the CPUID code directly forward host cache leaves to th= e guest */ > > bool cache_info_passthrough; > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > > index 6d008ab..c0f8efc 100644 > > --- a/target-i386/cpu.c > > +++ b/target-i386/cpu.c > > @@ -1318,18 +1318,18 @@ static void host_x86_cpu_initfn(Object *obj) > > X86CPU *cpu =3D X86_CPU(obj); > > CPUX86State *env =3D &cpu->env; > > KVMState *s =3D kvm_state; > > - FeatureWord w; > > = > > assert(kvm_enabled()); > > = > > + /* We can't fill the features array here because we don't know yet= if > > + * "migratable" is true or false. > > + */ > > + cpu->host_features =3D true; > > + > > env->cpuid_level =3D kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX= ); > > env->cpuid_xlevel =3D kvm_arch_get_supported_cpuid(s, 0x80000000, = 0, R_EAX); > > env->cpuid_xlevel2 =3D kvm_arch_get_supported_cpuid(s, 0xC0000000,= 0, R_EAX); > > = > > - for (w =3D 0; w < FEATURE_WORDS; w++) { > > - env->features[w] =3D > > - x86_cpu_get_supported_feature_word(w, cpu->migratable); > > - } > > object_property_set_bool(OBJECT(cpu), true, "pmu", &error_abort); > > } > > = > > @@ -1828,6 +1828,13 @@ static void x86_cpu_parse_featurestr(CPUState *c= s, char *features, > > featurestr =3D strtok(NULL, ","); > > } > > = > > + if (cpu->host_features) { > > + for (w =3D 0; w < FEATURE_WORDS; w++) { > > + env->features[w] =3D > > + x86_cpu_get_supported_feature_word(w, cpu->migratable); > > + } > > + } > > + > > for (w =3D 0; w < FEATURE_WORDS; w++) { > > env->features[w] |=3D plus_features[w]; > > env->features[w] &=3D ~minus_features[w]; > > -- = > > 1.9.3 > > = > = > -- = > Eduardo