linux-kernel - Re: [PATCH 05/18] Warn about unstable TSC

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Message-ID: <4C43140E.4070206@redhat.com>
Date:	Sun, 18 Jul 2010 17:47:42 +0300
From:	Avi Kivity <avi@...hat.com>
To:	Zachary Amsden <zamsden@...hat.com>
CC:	KVM <kvm@...r.kernel.org>, Marcelo Tosatti <mtosatti@...hat.com>,
	Glauber Costa <glommer@...hat.com>,
	Linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 05/18] Warn about unstable TSC

On 07/13/2010 05:25 AM, Zachary Amsden wrote:
> If creating an SMP guest with unstable host TSC, issue a warning
>
> Signed-off-by: Zachary Amsden<zamsden@...hat.com>
> ---
>   arch/x86/kvm/x86.c |    4 ++++
>   1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 2d5b97a..36ef649 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -5449,6 +5449,10 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
>   struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
>   						unsigned int id)
>   {
> +	if (check_tsc_unstable()&&  id != 0)
> +		printk_once(KERN_WARNING
> +		"kvm: SMP vm created on host with unstable TSC; "
> +		"guest TSC will not be reliable\n");
>   	return kvm_x86_ops->vcpu_create(kvm, id);
>   }
>
>    

'id' check not accurate (you can have a uniprocessor guest with id = 
1).  Better check online_vcpus.



-- 
error compiling committee.c: too many arguments to function

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