Re: [PATCH 3/9] KVM: SVM: Add tracepoint for nested vmrun

[Avi Kivity]

On 10/08/2009 06:15 PM, Joerg Roedel wrote:
> On Thu, Oct 08, 2009 at 05:58:22PM +0200, Avi Kivity wrote:
>    
> > On 10/08/2009 12:03 PM, Joerg Roedel wrote:
> >      
> > > This patch adds a dedicated kvm tracepoint for a nested
> > > vmrun.
> > >
> > > Signed-off-by: Joerg Roedel<joerg.roedel@xxxxxxx>
> > > ---
> > >   arch/x86/kvm/svm.c   |    6 ++++++
> > >   arch/x86/kvm/trace.h |   33 +++++++++++++++++++++++++++++++++
> > >   arch/x86/kvm/x86.c   |    1 +
> > >   3 files changed, 40 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> > > index 884bffc..907af3f 100644
> > > --- a/arch/x86/kvm/svm.c
> > > +++ b/arch/x86/kvm/svm.c
> > > @@ -1726,6 +1726,12 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
> > >   	/* nested_vmcb is our indicator if nested SVM is activated */
> > >   	svm->nested.vmcb = svm->vmcb->save.rax;
> > >
> > > +	trace_kvm_nested_vmrun(svm->vmcb->save.rip - 3, svm->nested.vmcb,
> > > +			       nested_vmcb->save.rip,
> > > +			       nested_vmcb->control.int_ctl,
> > > +			       nested_vmcb->control.event_inj,
> > > +			       nested_vmcb->control.nested_ctl);
> > > +
> > >        
> > It's better to pass only 'svm' as argument and have the tracepoint
> > code derive everything else, since (I think) argument setup is done
> > unconditionally, and only the actual trace_kvm call is patched out.
> > It may not work out due to where the trace code is compiled, but
> > it's worth trying.
> >      
> Hmm, struct vcpu_svm is defined in svm.c and local to that file. It is
> not known in x86.c, where the tracepoints are compiled, or in svm.c
> where trace.h is included. Is this tracepoint it worth it to move the
> definition of vcpu_svm into a (x86-)global header?
>    

I was talking about all svm tracepoints, but no, it isn't worth it.  
Let's leave it till later.

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

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