KVM: s390: ucontrol: export page faults to user

This patch introduces a new exit reason in the kvm_run structure
named KVM_EXIT_S390_UCONTROL. This exit indicates, that a virtual cpu
has regognized a fault on the host page table. The idea is that
userspace can handle this fault by mapping memory at the fault
location into the cpu's address space and then continue to run the
virtual cpu.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 0a66c1072691..7f686f6708b0 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -162,6 +162,7 @@ struct kvm_pit_config {
 #define KVM_EXIT_INTERNAL_ERROR   17
 #define KVM_EXIT_OSI              18
 #define KVM_EXIT_PAPR_HCALL       19
+#define KVM_EXIT_S390_UCONTROL    20
 
 /* For KVM_EXIT_INTERNAL_ERROR */
 #define KVM_INTERNAL_ERROR_EMULATION 1
@@ -249,6 +250,11 @@ struct kvm_run {
 #define KVM_S390_RESET_CPU_INIT  8
 #define KVM_S390_RESET_IPL       16
                 __u64 s390_reset_flags;
+                /* KVM_EXIT_S390_UCONTROL */
+                struct {
+                        __u64 trans_exc_code;
+                        __u32 pgm_code;
+                } s390_ucontrol;
                 /* KVM_EXIT_DCR */
                 struct {
                         __u32 dcrn;