kernel-hacking-2024-linux-s.../Documentation/virtual
David Hildenbrand 2444b352c3 KVM: s390: forward most SIGP orders to user space
Most SIGP orders are handled partially in kernel and partially in
user space. In order to:
- Get a correct SIGP SET PREFIX handler that informs user space
- Avoid race conditions between concurrently executed SIGP orders
- Serialize SIGP orders per VCPU

We need to handle all "slow" SIGP orders in user space. The remaining
ones to be handled completely in kernel are:
- SENSE
- SENSE RUNNING
- EXTERNAL CALL
- EMERGENCY SIGNAL
- CONDITIONAL EMERGENCY SIGNAL
According to the PoP, they have to be fast. They can be executed
without conflicting to the actions of other pending/concurrently
executing orders (e.g. STOP vs. START).

This patch introduces a new capability that will - when enabled -
forward all but the mentioned SIGP orders to user space. The
instruction counters in the kernel are still updated.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23 13:25:37 +01:00
..
kvm KVM: s390: forward most SIGP orders to user space 2015-01-23 13:25:37 +01:00
uml sched: Rename sched.c as sched/core.c in comments and Documentation 2013-06-19 12:58:42 +02:00
00-INDEX Remove Documentation/virtual/virtio-spec.txt 2013-03-12 15:45:18 +10:30