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

[Michael Mueller <mimu@linux.ibm.com>]

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);
>   }
>   

I ran hades tests as well. Thanks.

Here is my

Reviewed-by: Michael Mueller <mimu@linux.ibm.com>