On 18.12.20 15:18, Claudio Imbrenda wrote:
> Add kvm_s390_vsie_mvpg_check to perform the necessary checks in case an
> MVPG instruction intercepts in a VSIE guest.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
> ---
> arch/s390/kvm/gaccess.c | 55 +++++++++++++++++++++++++++++++++++++++++
> arch/s390/kvm/gaccess.h | 3 +++
> 2 files changed, 58 insertions(+)
>
> diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
> index 8e256a233583..90e9baff6eac 100644
> --- a/arch/s390/kvm/gaccess.c
> +++ b/arch/s390/kvm/gaccess.c
> @@ -1228,3 +1228,58 @@ int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *sg,
> mmap_read_unlock(sg->mm);
> return rc;
> }
> +
> +static int kvm_s390_mvpg_check_one(struct kvm_vcpu *vcpu, unsigned long *addr,
> + const int edat, const union asce asce,
> + const enum gacc_mode mode, unsigned long *pteptr)
> +{
> + enum prot_type prot;
> + int rc;
> +
> + rc = guest_translate(vcpu, *addr, addr, asce, mode, &prot, pteptr);
> + if (rc <= 0)
> + return rc;
> +
> + switch (rc) {
> + case PGM_REGION_FIRST_TRANS:
> + case PGM_REGION_SECOND_TRANS:
> + case PGM_REGION_THIRD_TRANS:
> + case PGM_SEGMENT_TRANSLATION:
> + if (!edat)
> + return trans_exc(vcpu, rc, *addr, 0, mode, prot);
> + *pteptr |= 4;
Hmmm, I wonder why that is necessary. Can't we set that in all relevant
cases in guest_translate() just as you do via
*entryptr |= dat_protection ? 6 : 4;
Can you enlighten me? :)
> + fallthrough;
> + case PGM_PAGE_TRANSLATION:
> + return -ENOENT;
> + default:
> + return rc;
> + }
> +}
> +
> +int kvm_s390_vsie_mvpg_check(struct kvm_vcpu *vcpu, unsigned long r1,
> + unsigned long r2, void *gpei)
> +{
> + unsigned long pei[2] = {0};
> + union ctlreg0 cr0;
> + union asce cr1;
> + int edat, rc1, rc2;
> +
> + cr0.val = vcpu->arch.sie_block->gcr[0];
> + cr1.val = vcpu->arch.sie_block->gcr[1];
> + edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
> +
> + rc1 = kvm_s390_mvpg_check_one(vcpu, &r1, edat, cr1, GACC_FETCH, pei);
> + rc2 = kvm_s390_mvpg_check_one(vcpu, &r2, edat, cr1, GACC_STORE, pei + 1);
> +
> + if (rc1 == -ENOENT || rc2 == -ENOENT) {
> + memcpy(gpei, pei, sizeof(pei));
I'd really prefer just passing two unsigned long pointers to
kvm_s390_vsie_mvpg_check() and eventually directly forwarding them to
kvm_s390_mvpg_check_one().
> + return -ENOENT;
> + }
> +
> + if (rc2 < 0)
> + return rc2;
> + if (rc1 < 0)
> + return rc1;
> +
> + return 0;
> +}
> diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
> index f4c51756c462..2c53cee3b29f 100644
> --- a/arch/s390/kvm/gaccess.h
> +++ b/arch/s390/kvm/gaccess.h
> @@ -166,6 +166,9 @@ int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
> int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
> unsigned long len, enum gacc_mode mode);
>
> +int kvm_s390_vsie_mvpg_check(struct kvm_vcpu *vcpu, unsigned long r1,
> + unsigned long r2, void *gpei);
> +
> int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
> void *data, unsigned long len, enum gacc_mode mode);
>
>
--
Thanks,
David / dhildenb
