From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-15?Q?Andreas_F=E4rber?= Subject: Re: [Qemu-devel] [PATCH v3 4/6] target-i386: Remove unsupported bits from all CPU models Date: Wed, 29 Oct 2014 18:26:43 +0100 Message-ID: <54512353.4000303@suse.de> References: <1412365191-22858-1-git-send-email-ehabkost@redhat.com> <1412365191-22858-5-git-send-email-ehabkost@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Paolo Bonzini , kvm@vger.kernel.org, Aurelien Jarno , Richard Henderson To: Eduardo Habkost , qemu-devel@nongnu.org Return-path: Received: from cantor2.suse.de ([195.135.220.15]:48836 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933998AbaJ2R0p (ORCPT ); Wed, 29 Oct 2014 13:26:45 -0400 In-Reply-To: <1412365191-22858-5-git-send-email-ehabkost@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Am 03.10.2014 um 21:39 schrieb Eduardo Habkost: > The following CPU features were never supported by neither TCG or KVM= , > so they are useless on the CPU model definitions, today: >=20 > * CPUID_DTS (DS) > * CPUID_HT > * CPUID_TM > * CPUID_PBE > * CPUID_EXT_DTES64 > * CPUID_EXT_DSCPL > * CPUID_EXT_EST > * CPUID_EXT_TM2 > * CPUID_EXT_XTPR > * CPUID_EXT_PDCM > * CPUID_SVM_LBRV >=20 > As using "enforce" mode is the only way to ensure guest ABI doesn't > change when moving to a different host, we should make "enforce" mode > the default or at least encourage management software to always use i= t. >=20 > In turn, to make "enforce" usable, we need CPU models that work witho= ut > always requiring some features to be explicitly disabled. This patch > removes the above features from all CPU model definitions. >=20 > We won't need any machine-type compat code for those changes, because= it > is impossible to have existing VMs with those features enabled. >=20 > Signed-off-by: Eduardo Habkost > Cc: Aurelien Jarno > --- > Changes v1 -> v2: > * Trivial typo fix in comment > --- > target-i386/cpu.c | 33 ++++++++++++++++++++------------- > 1 file changed, 20 insertions(+), 13 deletions(-) >=20 > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > index 4119fca..1e9fff9 100644 > --- a/target-i386/cpu.c > +++ b/target-i386/cpu.c > @@ -681,10 +681,11 @@ static X86CPUDefinition builtin_x86_defs[] =3D = { > .family =3D 16, > .model =3D 2, > .stepping =3D 3, > + /* Missing: CPUID_HT */ > .features[FEAT_1_EDX] =3D > PPRO_FEATURES | > CPUID_MTRR | CPUID_CLFLUSH | CPUID_MCA | > - CPUID_PSE36 | CPUID_VME | CPUID_HT, > + CPUID_PSE36 | CPUID_VME, > .features[FEAT_1_ECX] =3D > CPUID_EXT_SSE3 | CPUID_EXT_MONITOR | CPUID_EXT_CX16 | > CPUID_EXT_POPCNT, [snip] I'm okay with retaining these as comments. Anyone any objections? Andreas --=20 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imend=F6rffer; HRB 16746 AG N=FCrn= berg