Re: [PATCH] KVM: nVMX: Replace kvm_set_cr0 with vmx_set_cr0 in load_vmcs12_host_state

[Gleb Natapov <gleb@redhat.com>]

On Sun, Apr 28, 2013 at 12:20:38PM +0200, Jan Kiszka wrote:
> On 2013-02-23 22:35, Jan Kiszka wrote:
> > From: Jan Kiszka <jan.kiszka@siemens.com>
> > 
> > Likely a typo, but a fatal one as kvm_set_cr0 performs checks on the
> > state transition that may prevent loading L1's cr0.
> > 
> > Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> > ---
> >  arch/x86/kvm/vmx.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> > index 26d47e9..94f3b66 100644
> > --- a/arch/x86/kvm/vmx.c
> > +++ b/arch/x86/kvm/vmx.c
> > @@ -7429,7 +7429,7 @@ static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
> >  	 * fpu_active (which may have changed).
> >  	 * Note that vmx_set_cr0 refers to efer set above.
> >  	 */
> > -	kvm_set_cr0(vcpu, vmcs12->host_cr0);
> > +	vmx_set_cr0(vcpu, vmcs12->host_cr0);
> >  	/*
> >  	 * If we did fpu_activate()/fpu_deactivate() during L2's run, we need
> >  	 * to apply the same changes to L1's vmcs. We just set cr0 correctly,
> > 
> 
> This one still applies, is necessary for nested unrestricted guest mode,
> and I'm still convinced it's an appropriate way to fix the bug. How to
> proceed?
> 
What check that is done by kvm_set_cr0() fails?

--
			Gleb.