Commit ae4b60f6 authored by Nico Boehr's avatar Nico Boehr Committed by Heiko Carstens
Browse files

s390/nmi: fix virtual-physical address confusion 



When a machine check is received while in SIE, it is reinjected into the
guest in some cases. The respective code needs to access the sie_block,
which is taken from the backed up R14.

Since reinjection only occurs while we are in SIE (i.e. between the
labels sie_entry and sie_leave in entry.S and thus if CIF_MCCK_GUEST is
set), the backed up R14 will always contain a physical address in
s390_backup_mcck_info.

This currently works, because virtual and physical addresses are
the same.

Add phys_to_virt() to resolve the virtual-physical confusion.

Signed-off-by: default avatarNico Boehr <nrb@linux.ibm.com>
Reviewed-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/20230216121208.4390-2-nrb@linux.ibm.com


Signed-off-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 8ee0d2fb

arch/s390/kernel/nmi.c

+1 −2
Original line number Diff line number Diff line
@@ -346,8 +346,7 @@ static void notrace s390_backup_mcck_info(struct pt_regs *regs) 
	struct sie_page *sie_page;



	/* r14 contains the sie block, which was set in sie64a */

	struct kvm_s390_sie_block *sie_block =

			(struct kvm_s390_sie_block *) regs->gprs[14];

	struct kvm_s390_sie_block *sie_block = phys_to_virt(regs->gprs[14]);



	if (sie_block == NULL)

		/* Something's seriously wrong, stop system. */