On 02/07/2018 02:58 PM, David Hildenbrand wrote:
> On 07.02.2018 14:47, Collin L. Walling wrote:
>> On 02/07/2018 06:46 AM, David Hildenbrand wrote:
>>> Missed when enabling the Multiple-epoch facility. If the facility is
>>> installed and the control is set, a sign based comaprison has to be
>>> performed.
>>>
>>> Right now we would inject wrong interrupts and ignore interrupt
>>> conditions. Also the sleep time is calculated in a wrong way.
>>>
>>> Signed-off-by: David Hildenbrand<david@xxxxxxxxxx>
>>> ---
>>> arch/s390/kvm/interrupt.c | 25 +++++++++++++++++++------
>>> 1 file changed, 19 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
>>> index 3ea9cfa31b16..a616e9b65f91 100644
>>> --- a/arch/s390/kvm/interrupt.c
>>> +++ b/arch/s390/kvm/interrupt.c
>>> @@ -169,8 +169,15 @@ static int ckc_interrupts_enabled(struct kvm_vcpu *vcpu)
>>>
>>> static int ckc_irq_pending(struct kvm_vcpu *vcpu)
>>> {
>>> - if (vcpu->arch.sie_block->ckc >= kvm_s390_get_tod_clock_fast(vcpu->kvm))
>>> + const u64 now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
>>> + const u64 ckc = vcpu->arch.sie_block->ckc;
>>> +
>>> + if (vcpu->arch.sie_block->gcr[0] & 0x0020000000000000ul) {
>>> + if ((s64)ckc >= (s64)now)
>>> + return 0;
>>> + } else if (ckc >= now) {
>>> return 0;
>>> + }
>>> return ckc_interrupts_enabled(vcpu);
>>> }
>>>
>>> @@ -1042,13 +1049,19 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
>>>
>>> static u64 __calculate_sltime(struct kvm_vcpu *vcpu)
>>> {
>>> - u64 now, cputm, sltime = 0;
>>> + const u64 now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
>>> + const u64 ckc = vcpu->arch.sie_block->ckc;
>>> + u64 cputm, sltime = 0;
>>>
>>> if (ckc_interrupts_enabled(vcpu)) {
>>> - now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
>>> - sltime = tod_to_ns(vcpu->arch.sie_block->ckc - now);
>>> - /* already expired or overflow? */
>>> - if (!sltime || vcpu->arch.sie_block->ckc <= now)
>>> + if (vcpu->arch.sie_block->gcr[0] & 0x0020000000000000ul) {
>>> + if ((s64)now < (s64)ckc)
>>> + sltime = tod_to_ns((s64)ckc - (s64)now);
>>> + } else if (now < ckc) {
>>> + sltime = tod_to_ns(ckc - now);
>>> + }
>>> + /* already expired */
>>> + if (!sltime)
>>> return 0;
>>> if (cpu_timer_interrupts_enabled(vcpu)) {
>>> cputm = kvm_s390_get_cpu_timer(vcpu);
>> I think it would assist with readability if you defined the sign
>> comparison bit. Seeing
>> something that yells "SIGNED" would make sense as to what's going on here.
>
> If we want that than I suggest introducing defines for all control
> registers we use in kvm code in a separate patch.
We could add those defines to
arch/s390/include/asm/ctl_reg.h
