On 23.02.2018 12:04, Christian Borntraeger 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/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
>>> index 27918b15a8ba..22615af0b6e6 100644
>>> --- a/arch/s390/include/asm/kvm_host.h
>>> +++ b/arch/s390/include/asm/kvm_host.h
>>> @@ -294,6 +294,7 @@ struct kvm_vcpu_stat {
>>> u64 exit_userspace;
>>> u64 exit_null;
>>> u64 exit_external_request;
>>> + u64 exit_io_request;
>>> u64 exit_external_interrupt;
>>> u64 exit_stop_request;
>>> u64 exit_validity;
>>> 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;" ?
Yes, please do.
Can you also have a look if ICPT_KSS is correct?
I can see that we don't retry the instruction. So
vcpu->arch.sie_block->icptstatus might remain set.
1. For ICPT_KSS, has the PSW been forwarded? I assume not.
2. Can ICPT_KSS even set the icptstatus?
As we're retrying, no event is to be injected.
I assume a "return kvm_s390_skey_check_enable(vcpu)" can't hurt.
--
Thanks,
David / dhildenb
