Re: [PATCH v1] KVM: s390: interrupt: fix virtual-physical confusion for next alert GISA

Janosch Frank
2023-03-08T09:54:09Z

On 3/7/23 14:53, Michael Mueller wrote:
>
>
> On 23.02.23 17:22, Nico Boehr wrote:
>> We sometimes put a virtual address in next_alert, which should always be
>> a physical address, since it is shared with hardware.
>>
>> This currently works, because virtual and physical addresses are
>> the same.
>>
>> Add phys_to_virt() to resolve the virtual-physical confusion.
>>
>> Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
>> ---
>> arch/s390/kvm/interrupt.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
>> index ab26aa53ee37..20743c5b000a 100644
>> --- a/arch/s390/kvm/interrupt.c
>> +++ b/arch/s390/kvm/interrupt.c
>> @@ -305,7 +305,7 @@ static inline u8 gisa_get_ipm_or_restore_iam(struct kvm_s390_gisa_interrupt *gi)
>>
>> static inline int gisa_in_alert_list(struct kvm_s390_gisa *gisa)
>> {
>> - return READ_ONCE(gisa->next_alert) != (u32)(u64)gisa;
>> + return READ_ONCE(gisa->next_alert) != (u32)virt_to_phys(gisa);
>> }
>>
>> static inline void gisa_set_ipm_gisc(struct kvm_s390_gisa *gisa, u32 gisc)
>> @@ -3167,7 +3167,7 @@ void kvm_s390_gisa_init(struct kvm *kvm)
>> hrtimer_init(&gi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
>> gi->timer.function = gisa_vcpu_kicker;
>> memset(gi->origin, 0, sizeof(struct kvm_s390_gisa));
>> - gi->origin->next_alert = (u32)(u64)gi->origin;
>> + gi->origin->next_alert = (u32)virt_to_phys(gi->origin);
>> VM_EVENT(kvm, 3, "gisa 0x%pK initialized", gi->origin);
>> }
>>
>
> Here is my
>
> Signed-off-by: Michael Mueller <mimu@linux.ibm.com>

After a consultation with Michael I'm now a 100% sure this is a rev-by
and not a s-o-b. I've picked the patch with his rev-by.