| Message ID | 20230216121208.4390-2-nrb@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390: nmi: fix virtual-physical address confusion | expand |
On Thu, 16 Feb 2023 13:12:08 +0100 Nico Boehr <nrb@linux.ibm.com> wrote: > 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> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> > --- > arch/s390/kernel/nmi.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c > index 5dbf274719a9..56d9c559afa1 100644 > --- a/arch/s390/kernel/nmi.c > +++ b/arch/s390/kernel/nmi.c > @@ -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. */
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index 5dbf274719a9..56d9c559afa1 100644 --- a/arch/s390/kernel/nmi.c +++ b/arch/s390/kernel/nmi.c @@ -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. */
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 | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)