How about the attached alternative, which avoids repeated reads of
VM_INTR_INFO? Also I'm not sure whether checking for
VM_EXIT_REASONS_FAILED_VMENTRY is useful, so I removed it. After all,
EXIT_REASON_MCE_DURING_VMENTRY should imply it anyway.
Perhaps we should mask exit_reason down to 16 bits right at the top of the
vmexit handler? That would save us if new flags are added to
exit_reason[30:16], also.
Anyway, let me know what you think.
-- Keir
On 05/02/2010 10:22, "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx> wrote:
> Keir/Tim, here is attached patch. Please have a look onit.
>
> 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);
>
>
00-mce
Description: Binary data
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