Commit 0a28e065 authored by Claudio Imbrenda's avatar Claudio Imbrenda
Browse files

KVM: s390: Fix KVM_S390_VCPU_FAULT ioctl 



A previous commit changed the behaviour of the KVM_S390_VCPU_FAULT
ioctl. The current (wrong) implementation will trigger a guest
addressing exception if the requested address lies outside of a
memslot, unless the VM is UCONTROL.

Restore the previous behaviour by open coding the fault-in logic.

Fixes: 3762e905 ("KVM: s390: use __kvm_faultin_pfn()")
Acked-by: default avatarChristian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: default avatarSteffen Eiden <seiden@linux.ibm.com>
Signed-off-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
parent a12cc7e3

arch/s390/kvm/kvm-s390.c

+15 −3
Original line number Diff line number Diff line
@@ -5520,9 +5520,21 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
	}

#endif

	case KVM_S390_VCPU_FAULT: {

		idx = srcu_read_lock(&vcpu->kvm->srcu);

		r = vcpu_dat_fault_handler(vcpu, arg, 0);

		srcu_read_unlock(&vcpu->kvm->srcu, idx);

		gpa_t gaddr = arg;



		scoped_guard(srcu, &vcpu->kvm->srcu) {

			r = vcpu_ucontrol_translate(vcpu, &gaddr);

			if (r)

				break;



			r = kvm_s390_faultin_gfn_simple(vcpu, NULL, gpa_to_gfn(gaddr), false);

			if (r == PGM_ADDRESSING)

				r = -EFAULT;

			if (r <= 0)

				break;

			r = -EIO;

			KVM_BUG_ON(r, vcpu->kvm);

		}

		break;

	}

	case KVM_ENABLE_CAP: