5.4-stable review patch. If anyone has any objections, please let me know.
------------------
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)
