KVM: s390: sie intercept handling

This path introduces handling of sie intercepts in three flavors: Intercepts
are either handled completely in-kernel by kvm_handle_sie_intercept(),
or passed to userspace with corresponding data in struct kvm_run in case
kvm_handle_sie_intercept() returns -ENOTSUPP.
In case of partial execution in kernel with the need of userspace support,
kvm_handle_sie_intercept() may choose to set up struct kvm_run and return
-EREMOTE.

The trivial intercept reasons are handled in this patch:
handle_noop() just does nothing for intercepts that don't require our support
  at all
handle_stop() is called when a cpu enters stopped state, and it drops out to
  userland after updating our vcpu state
handle_validity() faults in the cpu lowcore if needed, or passes the request
  to userland

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 2367ff0c5dd0..f2acd6b9ab4d 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -74,6 +74,7 @@ struct kvm_irqchip {
 #define KVM_EXIT_INTR             10
 #define KVM_EXIT_SET_TPR          11
 #define KVM_EXIT_TPR_ACCESS       12
+#define KVM_EXIT_S390_SIEIC       13
 
 /* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
 struct kvm_run {
@@ -138,6 +139,14 @@ struct kvm_run {
                         __u32 is_write;
                         __u32 pad;
                 } tpr_access;
+                /* KVM_EXIT_S390_SIEIC */
+                struct {
+                        __u8 icptcode;
+                        __u64 mask; /* psw upper half */
+                        __u64 addr; /* psw lower half */
+                        __u16 ipa;
+                        __u32 ipb;
+                } s390_sieic;
                 /* Fix the size of the union. */
                 char padding[256];
         };