Re: [PATCH v2 9/9] KVM: x86: remove exit_int_info warning in svm_handle_exit

[Liam Merwick]

On 09/11/2022 09:15, Maxim Levitsky wrote:
> On Sun, 2022-11-06 at 15:53 +0000, Liam Merwick wrote:
> > On 03/11/2022 14:13, Maxim Levitsky wrote:
> > > It is valid to receive external interrupt and have broken IDT entry,
> > > which will lead to #GP with exit_int_into that will contain the index of
> > > the IDT entry (e.g any value).
> > >
> > > Other exceptions can happen as well, like #NP or #SS
> > > (if stack switch fails).
> > >
> > > Thus this warning can be user triggred and has very little value.
> > >
> > > Cc: stable@xxxxxxxxxxxxxxx
> > > Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
> > > ---
> > >    arch/x86/kvm/svm/svm.c | 9 ---------
> > >    1 file changed, 9 deletions(-)
> > >
> > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> > > index e9cec1b692051c..36f651ce842174 100644
> > > --- a/arch/x86/kvm/svm/svm.c
> > > +++ b/arch/x86/kvm/svm/svm.c
> > > @@ -3428,15 +3428,6 @@ static int svm_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
> > >                  return 0;
> > >          }
> > >    
> > > -       if (is_external_interrupt(svm->vmcb->control.exit_int_info) &&
> > > -           exit_code != SVM_EXIT_EXCP_BASE + PF_VECTOR &&
> > > -           exit_code != SVM_EXIT_NPF && exit_code != SVM_EXIT_TASK_SWITCH &&
> > > -           exit_code != SVM_EXIT_INTR && exit_code != SVM_EXIT_NMI)
> > > -               printk(KERN_ERR "%s: unexpected exit_int_info 0x%x "
> > > -                      "exit_code 0x%x\n",
> > > -                      __func__, svm->vmcb->control.exit_int_info,
> > > -                      exit_code);
> > > -
> > >          if (exit_fastpath != EXIT_FASTPATH_NONE)
> > >                  return 1;
> > >    
> >
> > This was the only caller of is_external_interrupt() - should the
> > definition be removed also to avoid a 'defined but not used' warning?
>
> I hate to say it but I have seen a warning about an unused function,
> but I really didn't expect that to come from this patch.
> I somehow thought that its some leftover in kvm/queue.
>
> I'll remove the unused function in a next version.

Reviewed-by: Liam Merwick <liam.merwick@xxxxxxxxxx>