Tim, thanks for review. I add printk here because that is something not always
happen.
--jyh
>-----Original Message-----
>From: Tim Deegan [mailto:Tim.Deegan@xxxxxxxxxx]
>Sent: Friday, February 05, 2010 6:42 PM
>To: Jiang, Yunhong
>Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Keir Fraser
>Subject: Re: [Xen-devel] RE: [PATCH] Don't enable irq for machine check vmexit
>
>At 10:22 +0000 on 05 Feb (1265365365), Jiang, Yunhong wrote:
>> Keir/Tim, here is attached patch. Please have a look onit.
>
>Yep, that looks better. Not sure that the dprintk is useful, though.
>
>Cheers,
>
>Tim.
>
>> Thanks
>> Yunhong Jiang
>>
>> # HG changeset patch
>> # User Yunhong Jiang <yunhong.jiang@xxxxxxxxx>
>> # Date 1265363638 -28800
>> # Node ID 01b2ce3f2cc95dd2e9c6defe2cee8a892e867187
>> # Parent 7b751b0e6f1bc7485b0718e634ed7cb9ce9ab68c
>> We should not enable irq for machine check VMExit
>>
>> In changeset 18658:824892134573, IRQ is enabled during VMExit except external
>interrupt. The exception should apply for machine check also, because :
>> a) The mce_logout_lock should be held in irq_disabled context.
>> b) The machine check event should be handled as quickly as possible, enable
>> irq will
>increase the period greatly.
>>
>> Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx>
>>
>> diff -r 7b751b0e6f1b -r 01b2ce3f2cc9 xen/arch/x86/hvm/vmx/vmx.c
>> --- a/xen/arch/x86/hvm/vmx/vmx.c Thu Feb 04 19:40:19 2010 +0000
>> +++ b/xen/arch/x86/hvm/vmx/vmx.c Fri Feb 05 17:53:58 2010 +0800
>> @@ -2168,7 +2168,7 @@ static void vmx_failed_vmentry(unsigned
>> case EXIT_REASON_MCE_DURING_VMENTRY:
>> printk("caused by machine check.\n");
>> HVMTRACE_0D(MCE);
>> - do_machine_check(regs);
>> + /* Handled already */
>> break;
>> default:
>> printk("reason not known yet!");
>> @@ -2259,6 +2259,23 @@ err:
>> err:
>> vmx_inject_hw_exception(TRAP_gp_fault, 0);
>> return -1;
>> +}
>> +
>> +int vmx_mce_exit(int exit_reason)
>> +{
>> + if ( unlikely(exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY &&
>> + (uint16_t)exit_reason == EXIT_REASON_MCE_DURING_VMENTRY) )
>> + return 1;
>> + else if (unlikely(exit_reason == EXIT_REASON_EXCEPTION_NMI))
>> + {
>> + uint32_t vector;
>> +
>> + vector = __vmread(VM_EXIT_INTR_INFO) &
>INTR_INFO_VECTOR_MASK;
>> + if (vector == TRAP_machine_check)
>> + return 1;
>> + }
>> +
>> + return 0;
>> }
>>
>> asmlinkage void vmx_vmexit_handler(struct cpu_user_regs *regs)
>> @@ -2287,6 +2304,9 @@ asmlinkage void vmx_vmexit_handler(struc
>> /* Handle the interrupt we missed before allowing any more in. */
>> if ( exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT )
>> vmx_do_extint(regs);
>> +
>> + if ( vmx_mce_exit(exit_reason) )
>> + do_machine_check(regs);
>>
>> /* Now enable interrupts so it's safe to take locks. */
>> local_irq_enable();
>> @@ -2447,8 +2467,9 @@ asmlinkage void vmx_vmexit_handler(struc
>> self_nmi(); /* Real NMI, vector 2: normal processing. */
>> break;
>> case TRAP_machine_check:
>> + dprintk(XENLOG_INFO, "VMexit for machine check\n");
>> HVMTRACE_0D(MCE);
>> - do_machine_check(regs);
>> + /* Handled already */
>> break;
>> case TRAP_invalid_op:
>> vmx_vmexit_ud_intercept(regs);
>>
>>
>
>
>Content-Description: ATT00001.txt
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel
>
>
>--
>Tim Deegan <Tim.Deegan@xxxxxxxxxx>
>Principal Software Engineer, Citrix Systems (R&D) Ltd.
>[Company #02300071, SL9 0DZ, UK.]
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