[S390] kvm: fix address mode switching
598841ca9919d008b520114d8a4378c4ce4e40a1 ([S390] use gmap address
spaces for kvm guest images) changed kvm to use a separate address
space for kvm guests. This address space was switched in __vcpu_run
In some cases (preemption, page fault) there is the possibility that
this address space switch is lost.
The typical symptom was a huge amount of validity intercepts or
random guest addressing exceptions.
Fix this by doing the switch in sie_loop and sie_exit and saving the
address space in the gmap structure itself. Also use the preempt
notifier.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 5f729d6..713da07 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -1076,6 +1076,11 @@
lg %r14,__LC_THREAD_INFO # pointer thread_info struct
tm __TI_flags+7(%r14),_TIF_EXIT_SIE
jnz sie_exit
+ lg %r14,__LC_GMAP # get gmap pointer
+ ltgr %r14,%r14
+ jz sie_gmap
+ lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce
+sie_gmap:
lg %r14,__SF_EMPTY(%r15) # get control block pointer
SPP __SF_EMPTY(%r15) # set guest id
sie 0(%r14)
@@ -1083,6 +1088,7 @@
SPP __LC_CMF_HPP # set host id
lg %r14,__LC_THREAD_INFO # pointer thread_info struct
sie_exit:
+ lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
ni __TI_flags+6(%r14),255-(_TIF_SIE>>8)
lg %r14,__SF_EMPTY+8(%r15) # load guest register save area
stmg %r0,%r13,0(%r14) # save guest gprs 0-13