4.19-stable review patch. If anyone has any objections, please let me know.
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From: Michael Mueller mimu@linux.ibm.com
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 --- 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)