From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marcelo Tosatti <mtosatti@redhat.com>
Subject: Re: [PATCH v4 4/8] KVM-HV: Add VCPU running/pre-empted state for
 guest
Date: Fri, 24 Aug 2012 12:02:49 -0300
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To: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
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On Fri, Aug 24, 2012 at 10:49:26AM +0530, Nikunj A Dadhania wrote:
> On Thu, 23 Aug 2012 08:46:22 -0300, Marcelo Tosatti <mtosatti@redhat.com> wrote:
> > On Tue, Aug 21, 2012 at 04:56:43PM +0530, Nikunj A. Dadhania wrote:
> > > From: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com>
> > > 
> > > Hypervisor code to indicate guest running/pre-empteded status through
> > > msr. The page is now pinned during MSR write time and use
> > > kmap_atomic/kunmap_atomic to access the shared area vcpu_state area.
> > > 
> > > Suggested-by: Marcelo Tosatti <mtosatti@redhat.com>
> > > Signed-off-by: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com>
> > > ---
> 
> [...]
> 
> > > +
> > > +static void kvm_set_vcpu_state(struct kvm_vcpu *vcpu)
> > > +{
> > > +	struct kvm_vcpu_state *vs;
> > > +	char *kaddr;
> > > +
> > > +	if (!((vcpu->arch.v_state.msr_val & KVM_MSR_ENABLED) &&
> > > +			vcpu->arch.v_state.vs_page))
> > > +		return;
> > 
> > It was agreed it was necessary to have valid vs_page only if MSR was
> > enabled? Or was that a misunderstanding?
> >
> There is a case where MSR is enabled but vs_page is NULL, this is
> gaurding that case. The check is now:
> 
> if (!(msr_enabled && vs_page))
>    return;
> 
> I had proposed that here:
> http://www.spinics.net/lists/kvm/msg77147.html

OK, its fine.