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@vger.kernel.org Signed-off-by: Claudio Imbrenda imbrenda@linux.ibm.com

---

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);