Re: 2.6.35-rc1 regression with pvclock and smp guests

Michael Tokarev
2010-09-30T23:02:48Z

30.09.2010 23:05, Marcelo Tosatti wrote:
[]
> Arjan, Michael, can you try the following:
>
> From 3823c018162dc708b543cbdc680a4c7d63533fee Mon Sep 17 00:00:00 2001
> From: Zachary Amsden <zamsden@redhat.com>
> Date: Sat, 29 May 2010 17:52:46 -1000
> Subject: [KVM V2 04/25] Fix SVM VMCB reset
> Cc: Avi Kivity <avi@redhat.com>,
> Marcelo Tosatti <mtosatti@redhat.com>,
> Glauber Costa <glommer@redhat.com>,
> linux-kernel@vger.kernel.org
>
> On reset, VMCB TSC should be set to zero. Instead, code was setting
> tsc_offset to zero, which passes through the underlying TSC.
>
> Signed-off-by: Zachary Amsden <zamsden@redhat.com>
> ---
> arch/x86/kvm/svm.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 760c86e..46856d2 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -781,7 +781,7 @@ static void init_vmcb(struct vcpu_svm *svm)
>
> control->iopm_base_pa = iopm_base;
> control->msrpm_base_pa = __pa(svm->msrpm);
> - control->tsc_offset = 0;
> + guest_write_tsc(&svm->vcpu, 0);
> control->int_ctl = V_INTR_MASKING_MASK;

This fails to compile on 2.6.35.5:

arch/x86/kvm/svm.c: In function ‘init_vmcb’:
arch/x86/kvm/svm.c:769: error: implicit declaration of function ‘guest_write_tsc’

I'll take a look tomorrow where that comes from.. hopefully ;)

Thanks!

/mjt