On Thu, Apr 9, 2020 at 5:11 PM Xu, Like <like.xu@xxxxxxxxx> wrote:
>
> Hi Bizjak,
>
> On 2020/4/9 19:49, Uros Bizjak wrote:
> > The function returns no value.
> >
> > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> > Fixes: 199cd1d7b534 ("KVM: SVM: Split svm_vcpu_run inline assembly to separate file")
> > Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
> > ---
> > arch/x86/kvm/svm/svm.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> > index 2be5bbae3a40..061d19e69c73 100644
> > --- a/arch/x86/kvm/svm/svm.c
> > +++ b/arch/x86/kvm/svm/svm.c
> > @@ -3276,7 +3276,7 @@ static void svm_cancel_injection(struct kvm_vcpu *vcpu)
> > svm_complete_interrupts(svm);
> > }
> >
> > -bool __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs);
> Just curious if __svm_vcpu_run() will fail to enter SVM guest mode,
> and a return value could indicate that nothing went wrong rather than
> blindly keeping silent.
vmload, vmrun and vmsave do not return anything in flags or registers,
so we can't detect anything at this point, modulo exception that is
handled below the respective instruction.
BTW: the change by itself does not change the generated code, the fake
return value from __svm_vcpu_run is already ignored. So, the change is
mostly cosmetic.
Uros.
