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authorHalil Pasic <pasic@linux.vnet.ibm.com>2016-01-25 21:10:40 +0300
committerCornelia Huck <cornelia.huck@de.ibm.com>2016-04-20 15:27:32 +0300
commit6d28f789bf81540d4069342b1a28bfd41dab38a3 (patch)
tree81573b9b5e05e974806c9b0473b8abd3800afe5a /Documentation
parentdad7eefbd048a2f44c990303751159671e988d13 (diff)
downloadlinux-6d28f789bf81540d4069342b1a28bfd41dab38a3.tar.xz
KVM: s390: add clear I/O irq operation for FLIC
Introduce a FLIC operation for clearing I/O interrupts for a subchannel. Rationale: According to the platform specification, pending I/O interruption requests have to be revoked in certain situations. For instance, according to the Principles of Operation (page 17-27), a subchannel put into the installed parameters initialized state is in the same state as after an I/O system reset (just parameters possibly changed). This implies that any I/O interrupts for that subchannel are no longer pending (as I/O system resets clear I/O interrupts). Therefore, we need an interface to clear pending I/O interrupts. Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/virtual/kvm/devices/s390_flic.txt6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt
index 646f47470f98..8478de1c0192 100644
--- a/Documentation/virtual/kvm/devices/s390_flic.txt
+++ b/Documentation/virtual/kvm/devices/s390_flic.txt
@@ -11,6 +11,7 @@ FLIC provides support to
- add interrupts (KVM_DEV_FLIC_ENQUEUE)
- inspect currently pending interrupts (KVM_FLIC_GET_ALL_IRQS)
- purge all pending floating interrupts (KVM_DEV_FLIC_CLEAR_IRQS)
+- purge one pending floating I/O interrupt (KVM_DEV_FLIC_CLEAR_IO_IRQ)
- enable/disable for the guest transparent async page faults
- register and modify adapter interrupt sources (KVM_DEV_FLIC_ADAPTER_*)
@@ -40,6 +41,11 @@ Groups:
Simply deletes all elements from the list of currently pending floating
interrupts. No interrupts are injected into the guest.
+ KVM_DEV_FLIC_CLEAR_IO_IRQ
+ Deletes one (if any) I/O interrupt for a subchannel identified by the
+ subsystem identification word passed via the buffer specified by
+ attr->addr (address) and attr->attr (length).
+
KVM_DEV_FLIC_APF_ENABLE
Enables async page faults for the guest. So in case of a major page fault
the host is allowed to handle this async and continues the guest.