diff options
| author | Fan Zhang <zhangfan@linux.vnet.ibm.com> | 2015-05-13 10:58:41 +0200 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2015-08-04 14:38:37 +0200 |
| commit | fdf036507f1fc036d5a06753e9e8b13f46de73e8 (patch) | |
| tree | b9533136fecbd73e24f9e955edcd261060ee5957 /arch/s390/include | |
| parent | 554726d33c20791653dbd1c047c83f93459bc586 (diff) | |
KVM: s390: host STP toleration for VMs
If the host has STP enabled, the TOD of the host will be changed during
synchronization phases. These are performed during a stop_machine() call.
As the guest TOD is based on the host TOD, we have to make sure that:
- no VCPU is in the SIE (implicitly guaranteed via stop_machine())
- manual guest TOD calculations are not affected
"Epoch" is the guest TOD clock delta to the host TOD clock. We have to
adjust that value during the STP synchronization and make sure that code
that accesses the epoch won't get interrupted in between (via disabling
preemption).
Signed-off-by: Fan Zhang <zhangfan@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/include')
| -rw-r--r-- | arch/s390/include/asm/etr.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/s390/include/asm/etr.h b/arch/s390/include/asm/etr.h index 629b79a93165..f7e5c36688c3 100644 --- a/arch/s390/include/asm/etr.h +++ b/arch/s390/include/asm/etr.h @@ -214,6 +214,9 @@ static inline int etr_ptff(void *ptff_block, unsigned int func) void etr_switch_to_local(void); void etr_sync_check(void); +/* notifier for syncs */ +extern struct atomic_notifier_head s390_epoch_delta_notifier; + /* STP interruption parameter */ struct stp_irq_parm { unsigned int _pad0 : 14; |