[PATCH v1 1/1] s390: nmi: fix virtual-physical address confusion

[Nico Boehr <nrb@linux.ibm.com>]

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: Nico Boehr <nrb@linux.ibm.com>
---
 arch/s390/kernel/nmi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 5dbf274719a9..322160328866 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -347,7 +347,7 @@ static void notrace s390_backup_mcck_info(struct pt_regs *regs)
 
 	/* 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 *)phys_to_virt(regs->gprs[14]);
 
 	if (sie_block == NULL)
 		/* Something's seriously wrong, stop system. */
-- 
2.39.1