From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54528) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1alc93-0002zK-EW for qemu-devel@nongnu.org; Thu, 31 Mar 2016 08:56:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1alc8y-00058T-Ev for qemu-devel@nongnu.org; Thu, 31 Mar 2016 08:56:17 -0400 References: <1459371583-4824-1-git-send-email-pbonzini@redhat.com> From: Laszlo Ersek Message-ID: <56FD1E68.5020604@redhat.com> Date: Thu, 31 Mar 2016 14:56:08 +0200 MIME-Version: 1.0 In-Reply-To: <1459371583-4824-1-git-send-email-pbonzini@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] target-i386: do not read/write MSR_TSC_AUX from KVM if CPUID bit is not set List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , qemu-devel@nongnu.org Cc: ehabkost@redhat.com, qemu-stable@nongnu.org On 03/30/16 22:59, Paolo Bonzini wrote: > KVM does not let you read or write this MSR if the corresponding CPUID > bit is not set. This in turn causes MSRs that come after MSR_TSC_AUX > to be ignored by KVM_SET_MRSS. typo: KVM_SET_MRSS / KVM_SET_MSRS Thanks for fixing this. Laszlo > > One visible symptom is that s3.flat from kvm-unit-tests fails with > CPUs that do not have RDTSCP, because the SMBASE is not reset to > 0x30000 after reset. > > Fixes: c9b8f6b6210847b4381c5b2ee172b1c7eb9985d6 > Cc: qemu-stable@nongnu.org > Signed-off-by: Paolo Bonzini > --- > target-i386/kvm.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/target-i386/kvm.c b/target-i386/kvm.c > index 87ab969..19e2d94 100644 > --- a/target-i386/kvm.c > +++ b/target-i386/kvm.c > @@ -917,6 +917,9 @@ int kvm_arch_init_vcpu(CPUState *cs) > if (env->features[FEAT_1_EDX] & CPUID_MTRR) { > has_msr_mtrr = true; > } > + if (!(env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_RDTSCP)) { > + has_msr_tsc_aux = false; > + } > > return 0; > } >