From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Wolf Subject: Re: [PATCH v3 3/4] KVM: SVM: Fix CPL updates Date: Mon, 06 Feb 2012 10:18:35 +0100 Message-ID: <4F2F9AEB.9080406@redhat.com> References: <1328293765-13663-1-git-send-email-kwolf@redhat.com> <1328293765-13663-4-git-send-email-kwolf@redhat.com> <20120205111617.GT23536@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, joerg.roedel@amd.com, yoshikawa.takuya@oss.ntt.co.jp, avi@redhat.com, mtosatti@redhat.com To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33410 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753991Ab2BFJPM (ORCPT ); Mon, 6 Feb 2012 04:15:12 -0500 In-Reply-To: <20120205111617.GT23536@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Am 05.02.2012 12:16, schrieb Gleb Natapov: > On Fri, Feb 03, 2012 at 07:29:24PM +0100, Kevin Wolf wrote: >> Keep CPL at 0 in real mode and at 3 in VM86. In protected/long mode, use >> RPL rather than DPL of the code segment. >> >> Signed-off-by: Kevin Wolf >> --- >> arch/x86/kvm/svm.c | 19 ++++++++++++++++--- >> 1 files changed, 16 insertions(+), 3 deletions(-) >> >> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c >> index 6a977c1..4124a7e 100644 >> --- a/arch/x86/kvm/svm.c >> +++ b/arch/x86/kvm/svm.c >> @@ -1263,6 +1263,21 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu) >> wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]); >> } >> >> +static void svm_update_cpl(struct kvm_vcpu *vcpu) >> +{ >> + struct vcpu_svm *svm = to_svm(vcpu); >> + int cpl; >> + >> + if (!is_protmode(vcpu)) >> + cpl = 0; >> + else if (svm->vmcb->save.rflags & X86_EFLAGS_VM) >> + cpl = 3; >> + else >> + cpl = svm->vmcb->save.cs.selector & 0x3; >> + >> + svm->vmcb->save.cpl = cpl; >> +} >> + > As you probably know already I think cpl should be updated in > svm_get_rflags() too. With current patch restoring CS segment > register before rflags register after migration may cause cpl > to get wrong value for instance. I think you mean set_rflags rather than get_rflags? Patch 4 adds this with the set_rflags emulator callback. Kevin