From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH -v3] KVM: Add VT-x machine check support Date: Mon, 08 Jun 2009 11:48:13 +0300 Message-ID: <4A2CD04D.7070603@redhat.com> References: <1244449939.8361.591.camel@yhuang-dev.sh.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , Andi Kleen To: Huang Ying Return-path: In-Reply-To: <1244449939.8361.591.camel@yhuang-dev.sh.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Huang Ying wrote: > From: Andi Kleen > > VT-x needs an explicit MC vector intercept to handle machine checks in the > hyper visor. > > It also has a special option to catch machine checks that happen > during VT entry. > > Do these interceptions and forward them to the Linux machine check > handler. Make it always look like user space is interrupted because > the machine check handler treats kernel/user space differently. > > Thanks to Jiang Yunhong for help and testing. > > Noticed an additional problem. See below. > static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) > { > struct vcpu_vmx *vmx = to_vmx(vcpu); > @@ -2616,6 +2640,10 @@ static int handle_exception(struct kvm_v > vect_info = vmx->idt_vectoring_info; > intr_info = vmcs_read32(VM_EXIT_INTR_INFO); > > + ex_no = intr_info & INTR_INFO_VECTOR_MASK; > + if (ex_no == MC_VECTOR) > + return handle_machine_check(vcpu, kvm_run); > + > It isn't sufficient to check the vector number; you also need to check the interrupt type. See for example is_page_fault() and is_no_device(). I suggest you add an is_machine_check() along similar lines. Later we can collapse all those functions to use a single helper. > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -382,6 +382,8 @@ struct kvm_vcpu_arch { > u64 mcg_status; > u64 mcg_ctl; > u64 *mce_banks; > + > + u32 exit_reason; > }; > Please move this into struct vcpu_vmx. -- error compiling committee.c: too many arguments to function