From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:47191) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tw9ek-0004ga-GG for qemu-devel@nongnu.org; Fri, 18 Jan 2013 05:58:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tw9ei-0006im-PP for qemu-devel@nongnu.org; Fri, 18 Jan 2013 05:58:42 -0500 Received: from cantor2.suse.de ([195.135.220.15]:32801 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tw9ei-0006ii-Fy for qemu-devel@nongnu.org; Fri, 18 Jan 2013 05:58:40 -0500 Message-ID: <50F92ADA.9080203@suse.de> Date: Fri, 18 Jan 2013 11:58:34 +0100 From: =?ISO-8859-15?Q?Andreas_F=E4rber?= MIME-Version: 1.0 References: <1358456378-29248-1-git-send-email-ehabkost@redhat.com> <1358456378-29248-3-git-send-email-ehabkost@redhat.com> In-Reply-To: <1358456378-29248-3-git-send-email-ehabkost@redhat.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH for-1.4 02/12] target-i386: Don't set any KVM flag by default if KVM is disabled List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: Igor Mammedov , Gleb Natapov , qemu-devel@nongnu.org, Anthony Liguori , "kvm@vger.kernel.org list" Am 17.01.2013 21:59, schrieb Eduardo Habkost: > This is a cleanup that tries to solve two small issues: >=20 > - We don't need a separate kvm_pv_eoi_features variable just to keep a > constant calculated at compile-time, and this style would require > adding a separate variable (that's declared twice because of the > CONFIG_KVM ifdef) for each feature that's going to be enabled/disabl= e > by machine-type compat code. > - The pc-1.3 code is setting the kvm_pv_eoi flag on cpuid_kvm_features > even when KVM is disabled at runtime. This small incosistency in > the cpuid_kvm_features field isn't a problem today because > cpuid_kvm_features is ignored by the TCG code, but it may cause > unexpected problems later when refactoring the CPUID handling code. >=20 > This patch eliminates the kvm_pv_eoi_features variable and simply uses > kvm_enabled() inside the enable_kvm_pv_eoi() compat function, so it > enables kvm_pv_eoi only if KVM is enabled. I believe this makes the > behavior of enable_kvm_pv_eoi() clearer and easier to understand. >=20 > Signed-off-by: Eduardo Habkost Fine with me if KVM folks agree. Andreas > --- > Cc: kvm@vger.kernel.org > Cc: Michael S. Tsirkin > Cc: Gleb Natapov > Cc: Marcelo Tosatti >=20 > Changes v2: > - Coding style fix >=20 > Changes v3: > - Eliminate #ifdef by using the fake KVM_FEATURE_PV_EOI #define >=20 > Changes v4: > - Check kvm_enabled() when actually using kvm_default_features > - Eliminate Yet Another #ifdef by using the fake KVM_FEATURE_* > #defines on kvm_default_features initialization >=20 > Changes v5: > - Rebase and move the kvm_enabled() check to cpu_x86_register() > --- > target-i386/cpu.c | 12 ++++-------- > 1 file changed, 4 insertions(+), 8 deletions(-) >=20 > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > index 333745b..754eb6f 100644 > --- a/target-i386/cpu.c > +++ b/target-i386/cpu.c > @@ -206,22 +206,16 @@ typedef struct model_features_t { > int check_cpuid =3D 0; > int enforce_cpuid =3D 0; > =20 > -#if defined(CONFIG_KVM) > static uint32_t kvm_default_features =3D (1 << KVM_FEATURE_CLOCKSOURCE= ) | > (1 << KVM_FEATURE_NOP_IO_DELAY) | > (1 << KVM_FEATURE_CLOCKSOURCE2) | > (1 << KVM_FEATURE_ASYNC_PF) | > (1 << KVM_FEATURE_STEAL_TIME) | > (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT); > -static const uint32_t kvm_pv_eoi_features =3D (0x1 << KVM_FEATURE_PV_E= OI); > -#else > -static uint32_t kvm_default_features =3D 0; > -static const uint32_t kvm_pv_eoi_features =3D 0; > -#endif > =20 > void enable_kvm_pv_eoi(void) > { > - kvm_default_features |=3D kvm_pv_eoi_features; > + kvm_default_features |=3D (1UL << KVM_FEATURE_PV_EOI); > } > =20 > void host_cpuid(uint32_t function, uint32_t count, > @@ -1602,7 +1596,9 @@ int cpu_x86_register(X86CPU *cpu, const char *cpu= _model) > goto out; > } > =20 > - def->kvm_features |=3D kvm_default_features; > + if (kvm_enabled()) { > + def->kvm_features |=3D kvm_default_features; > + } > def->ext_features |=3D CPUID_EXT_HYPERVISOR; > =20 > if (cpu_x86_parse_featurestr(def, features) < 0) { >=20 --=20 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imend=F6rffer; HRB 16746 AG N=FCrnbe= rg