Re: [PATCH 7/9] KVM: VMX: Refactor vmx_complete_atomic_exit()

[Avi Kivity <avi@redhat.com>]

On 03/15/2011 11:40 PM, Marcelo Tosatti wrote:
> On Tue, Mar 08, 2011 at 03:57:43PM +0200, Avi Kivity wrote:
> >  Move the exit reason checks to the front of the function, for early
> >  exit in the common case.
> >
>
> >
> >   static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
> >   {
> >  -	u32 exit_intr_info = vmx->exit_intr_info;
> >  +	u32 exit_intr_info;
> >  +
> >  +	if (!(vmx->exit_reason == EXIT_REASON_MCE_DURING_VMENTRY
> >  +	      || vmx->exit_reason == EXIT_REASON_EXCEPTION_NMI))
> >  +		return;
> >  +
> >  +	exit_intr_info = vmx->exit_intr_info;
>
> So you're saving a vmread on exception and mce_during_vmentry exits?

Well, the real goal is patch 8, which removes the unconditional read of 
VM_EXIT_INTR_INFO.  Right now we have 2 reads on exceptions and one on 
other exits, we drop both by 1.

> Managing nmi_known_unmasked appears tricky... perhaps worthwhile to
> have it in a helper that sets the bit in interruptibility info +
> nmi_known_unmasked.

I'll look into it, likely as an add-on patch.

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