KVM: s390: Change virtual to physical address access in diag 0x258 handler

commit cad4b3d4ab1f062708fff33f44d246853f51e966 upstream.

The parameters for the diag 0x258 are real addresses, not virtual, but
KVM was using them as virtual addresses. This only happened to work, since
the Linux kernel as a guest used to have a 1:1 mapping for physical vs
virtual addresses.

Fix KVM so that it correctly uses the addresses as real addresses.

Cc: stable@vger.kernel.org
Fixes: 8ae04b8f500b ("KVM: s390: Guest's memory access functions get access registers")
Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20240917151904.74314-3-nrb@linux.ibm.com
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index 5b8ec1c447e141a710f17b5466ee90e0360d91c5..01582fb5ad65fca5958ef4a12d58ed834d5642c8 100644 (file)
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -77,7 +77,7 @@ static int __diag_page_ref_service(struct kvm_vcpu *vcpu)
        vcpu->stat.diagnose_258++;
        if (vcpu->run->s.regs.gprs[rx] & 7)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
-       rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm));
+       rc = read_guest_real(vcpu, vcpu->run->s.regs.gprs[rx], &parm, sizeof(parm));
        if (rc)
                return kvm_s390_inject_prog_cond(vcpu, rc);
        if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258)