On Fri, 23 Feb 2018 12:04:19 +0100
Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote:
> On 02/23/2018 12:00 PM, David Hildenbrand wrote:
> > On 23.02.2018 09:11, Christian Borntraeger wrote:
> >> We want to count IO exit requests in kvm_stat. At the same time
> >> we can get rid of the handle_noop function.
> >>
> >> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> >> ---
> >> arch/s390/include/asm/kvm_host.h | 1 +
> >> arch/s390/kvm/intercept.c | 19 +++++--------------
> >> arch/s390/kvm/kvm-s390.c | 1 +
> >> 3 files changed, 7 insertions(+), 14 deletions(-)
> >> diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
> >> index 07c6e81163bf..cad2ea216007 100644
> >> --- a/arch/s390/kvm/intercept.c
> >> +++ b/arch/s390/kvm/intercept.c
> >> @@ -50,18 +50,6 @@ u8 kvm_s390_get_ilen(struct kvm_vcpu *vcpu)
> >> return ilen;
> >> }
> >>
> >> -static int handle_noop(struct kvm_vcpu *vcpu)
> >> -{
> >> - switch (vcpu->arch.sie_block->icptcode) {
> >> - case 0x10:
> >> - vcpu->stat.exit_external_request++;
> >> - break;
> >> - default:
> >> - break; /* nothing */
> >> - }
> >> - return 0;
> >> -}
> >> -
> >> static int handle_stop(struct kvm_vcpu *vcpu)
> >> {
> >> struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
> >> @@ -458,15 +446,18 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
> >>
> >> int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
> >> {
> >> - int rc, per_rc = 0;
> >> + int rc = 0, per_rc = 0;
> >>
> >> if (kvm_is_ucontrol(vcpu->kvm))
> >> return -EOPNOTSUPP;
> >>
> >> switch (vcpu->arch.sie_block->icptcode) {
> >> case ICPT_EXTREQ:
> >> + vcpu->stat.exit_external_request++;
> >> + break;
> >> case ICPT_IOREQ:
> >> - return handle_noop(vcpu);
> >> + vcpu->stat.exit_io_request++;
> >> + break;
> >
> > You now end up executing the code following this switch-case.
> >
> > But I assume vcpu->arch.sie_block->icptstatus will never indicate
> > instruction fetching, so this should be fine.
>
> To play safe I could replace the "break;" with "return 0;" ?
At least that would make it clear that this patch does not intend to
change behaviour.
