| Message ID | 1244449939.8361.591.camel@yhuang-dev.sh.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Huang Ying wrote: > From: Andi Kleen <ak@linux.intel.com> > > 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.
On Mon, 2009-06-08 at 16:48 +0800, Avi Kivity wrote: > Huang Ying wrote: > > From: Andi Kleen <ak@linux.intel.com> > > > > 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. OK. I will do this. > > --- 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. OK. Best Regards, Huang Ying -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- a/arch/x86/include/asm/vmx.h +++ b/arch/x86/include/asm/vmx.h @@ -247,6 +247,7 @@ enum vmcs_field { #define EXIT_REASON_MSR_READ 31 #define EXIT_REASON_MSR_WRITE 32 #define EXIT_REASON_MWAIT_INSTRUCTION 36 +#define EXIT_REASON_MCE_DURING_VMENTRY 41 #define EXIT_REASON_TPR_BELOW_THRESHOLD 43 #define EXIT_REASON_APIC_ACCESS 44 #define EXIT_REASON_EPT_VIOLATION 48 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -32,6 +32,7 @@ #include <asm/desc.h> #include <asm/vmx.h> #include <asm/virtext.h> +#include <asm/mce.h> #define __ex(x) __kvm_handle_fault_on_reboot(x) @@ -487,7 +488,7 @@ static void update_exception_bitmap(stru { u32 eb; - eb = (1u << PF_VECTOR) | (1u << UD_VECTOR); + eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR); if (!vcpu->fpu_active) eb |= 1u << NM_VECTOR; if (vcpu->guest_debug & KVM_GUESTDBG_ENABLE) { @@ -2605,6 +2606,29 @@ static int handle_rmode_exception(struct return 0; } +/* + * Trigger machine check on the host. We assume all the MSRs are already set up + * by the CPU and that we still run on the same CPU as the MCE occurred on. + * We pass a fake environment to the machine check handler because we want + * the guest to be always treated like user space, no matter what context + * it used internally. + */ +static void kvm_machine_check(void) +{ + struct pt_regs regs = { + .cs = 3, /* Fake ring 3 no matter what the guest ran on */ + .flags = X86_EFLAGS_IF, + }; + + do_machine_check(®s, 0); +} + +static int handle_machine_check(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) +{ + /* already handled by vcpu_run */ + return 1; +} + 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); + if ((vect_info & VECTORING_INFO_VALID_MASK) && !is_page_fault(intr_info)) printk(KERN_ERR "%s: unexpected, vectoring info 0x%x " @@ -2662,7 +2690,6 @@ static int handle_exception(struct kvm_v return 1; } - ex_no = intr_info & INTR_INFO_VECTOR_MASK; switch (ex_no) { case DB_VECTOR: dr6 = vmcs_readl(EXIT_QUALIFICATION); @@ -3189,6 +3216,7 @@ static int (*kvm_vmx_exit_handlers[])(st [EXIT_REASON_WBINVD] = handle_wbinvd, [EXIT_REASON_TASK_SWITCH] = handle_task_switch, [EXIT_REASON_EPT_VIOLATION] = handle_ept_violation, + [EXIT_REASON_MCE_DURING_VMENTRY] = handle_machine_check, }; static const int kvm_vmx_max_exit_handlers = @@ -3200,7 +3228,7 @@ static const int kvm_vmx_max_exit_handle */ static int vmx_handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) { - u32 exit_reason = vmcs_read32(VM_EXIT_REASON); + u32 exit_reason = vcpu->arch.exit_reason; struct vcpu_vmx *vmx = to_vmx(vcpu); u32 vectoring_info = vmx->idt_vectoring_info; @@ -3284,6 +3312,13 @@ static void vmx_complete_interrupts(stru exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO); + vmx->vcpu.arch.exit_reason = vmcs_read32(VM_EXIT_REASON); + + /* Handle machine checks before interrupts are enabled */ + if ((vmx->vcpu.arch.exit_reason == EXIT_REASON_MCE_DURING_VMENTRY) || + (exit_intr_info & INTR_INFO_VECTOR_MASK) == MC_VECTOR) + kvm_machine_check(); + /* We need to handle NMIs before interrupts are enabled */ if ((exit_intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_NMI_INTR && (exit_intr_info & INTR_INFO_VALID_MASK)) { --- 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; }; struct kvm_mem_alias { --- a/arch/x86/kernel/cpu/mcheck/mce_64.c +++ b/arch/x86/kernel/cpu/mcheck/mce_64.c @@ -420,6 +420,7 @@ void do_machine_check(struct pt_regs * r out2: atomic_dec(&mce_entry); } +EXPORT_SYMBOL_GPL(do_machine_check); #ifdef CONFIG_X86_MCE_INTEL /***