From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 03/10] KVM: SVM: Fix schedule-while-atomic on nested exception handling Date: Thu, 18 Feb 2010 15:52:20 +0200 Message-ID: <4B7D4614.7040806@redhat.com> References: <1266493115-28386-1-git-send-email-joerg.roedel@amd.com> <1266493115-28386-4-git-send-email-joerg.roedel@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org To: Joerg Roedel Return-path: In-Reply-To: <1266493115-28386-4-git-send-email-joerg.roedel@amd.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 02/18/2010 01:38 PM, Joerg Roedel wrote: > Move the actual vmexit routine out of code that runs with > irqs and preemption disabled. > > Cc: stable@kernel.org > Signed-off-by: Joerg Roedel > --- > arch/x86/kvm/svm.c | 20 +++++++++++++++++--- > 1 files changed, 17 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 7c96b8b..25d26ec 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -128,6 +128,7 @@ static void svm_flush_tlb(struct kvm_vcpu *vcpu); > static void svm_complete_interrupts(struct vcpu_svm *svm); > > static int nested_svm_exit_handled(struct vcpu_svm *svm); > +static int nested_svm_exit_handled_atomic(struct vcpu_svm *svm); > static int nested_svm_vmexit(struct vcpu_svm *svm); > static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr, > bool has_error_code, u32 error_code); > @@ -1386,7 +1387,7 @@ static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr, > svm->vmcb->control.exit_info_1 = error_code; > svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2; > > - return nested_svm_exit_handled(svm); > + return nested_svm_exit_handled_atomic(svm); > } > What do you say to if (nested_svm_intercepts(svm)) svm->nested.exit_required = true; here, and recoding nested_svm_exit_handled() to call nested_svm_intercepts()? I think it improves readability a little by avoiding a function that changes behaviour according to how it is called. Long term, we may want to split out the big switch into the individual handlers, to avoid decoding the exit reason twice. -- error compiling committee.c: too many arguments to function