Re: [PATCH] KVM: x86: Remove user space triggerable MCE error message

[Huang Ying <ying.huang@intel.com>]

On Sat, 2011-01-15 at 17:00 +0800, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
> 
> This case is a pure user space error we do not need to record. Moreover,
> it can be misused to flood the kernel log. Remove it.

I don't think this is a pure user space error.  This happens on real
hardware too, if the Machine Check exception is raised during early boot
stage or the second MC exception is raised before the first MC exception
is processed/cleared.

So I use printk here to help debugging these issues.

To avoid flooding the kernel log, we can use ratelimit.

Best Regards,
Huang Ying

> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  arch/x86/kvm/x86.c |    3 ---
>  1 files changed, 0 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 9dda70d..7f7e4a5 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -2575,9 +2575,6 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
>  	if (mce->status & MCI_STATUS_UC) {
>  		if ((vcpu->arch.mcg_status & MCG_STATUS_MCIP) ||
>  		    !kvm_read_cr4_bits(vcpu, X86_CR4_MCE)) {
> -			printk(KERN_DEBUG "kvm: set_mce: "
> -			       "injects mce exception while "
> -			       "previous one is in progress!\n");
>  			kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
>  			return 0;
>  		}