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

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>

diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index 2a32438e09cebaa698a8935c4aec03bf1f2cbc58..74f73141f9b96b5dcebe2f6a92c55fa161aaf118 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.instruction_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)