From: Michael Mueller <mimu@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx Fixes: 8ae04b8f500b ("KVM: s390: Guest's memory access functions get access registers") Suggested-by: Vasily Gorbik <gor@xxxxxxxxxxxxx> Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxx> Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx> Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx> Reviewed-by: Heiko Carstens <hca@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240917151904.74314-3-nrb@xxxxxxxxxxxxx Acked-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/s390/kvm/diag.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/s390/kvm/diag.c +++ b/arch/s390/kvm/diag.c @@ -78,7 +78,7 @@ static int __diag_page_ref_service(struc 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) Patches currently in stable-queue which might be from mimu@xxxxxxxxxxxxx are queue-4.19/kvm-s390-change-virtual-to-physical-address-access-in-diag-0x258-handler.patch