Re: [PATCH RFC 2/5] s390x: implement diag260

[Cornelia Huck]

On Mon, 13 Jul 2020 13:54:41 +0200
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> On 10.07.20 10:32, David Hildenbrand wrote:
> 
> >>> --- a/target/s390x/misc_helper.c
> >>> +++ b/target/s390x/misc_helper.c
> >>> @@ -116,6 +116,12 @@ void HELPER(diag)(CPUS390XState *env, uint32_t r1, 
> >>> uint32_t r3, uint32_t num)
> >>>      uint64_t r;
> >>>  
> >>>      switch (num) {
> >>> +    case 0x260:
> >>> +        qemu_mutex_lock_iothread();
> >>> +        handle_diag_260(env, r1, r3, GETPC());
> >>> +        qemu_mutex_unlock_iothread();
> >>> +        r = 0;
> >>> +        break;
> >>>      case 0x500:
> >>>          /* KVM hypercall */
> >>>          qemu_mutex_lock_iothread();  
> >>
> >> Looking at the doc referenced above, it seems that we treat every diag
> >> call as privileged under tcg; but it seems that 0x44 isn't? (Unrelated
> >> to your patch; maybe I'm misreading.)  
> > 
> > That's also a BUG in kvm then?
> > 
> > int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
> > {
> > ...
> >     if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
> >             return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
> > ...
> > }  
> 
> diag 44 gives a PRIVOP on LPAR, so I think this is fine. 
> 

Seems like a bug/inconsistency in CP (or its documentation), then.