KVM: s390: Add support for channel I/O instructions.
Add a new capability, KVM_CAP_S390_CSS_SUPPORT, which will pass
intercepts for channel I/O instructions to userspace. Only I/O
instructions interacting with I/O interrupts need to be handled
in-kernel:
- TEST PENDING INTERRUPTION (tpi) dequeues and stores pending
interrupts entirely in-kernel.
- TEST SUBCHANNEL (tsch) dequeues pending interrupts in-kernel
and exits via KVM_EXIT_S390_TSCH to userspace for subchannel-
related processing.
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 80bb3b8..8bb0bf8 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -168,6 +168,7 @@
#define KVM_EXIT_PAPR_HCALL 19
#define KVM_EXIT_S390_UCONTROL 20
#define KVM_EXIT_WATCHDOG 21
+#define KVM_EXIT_S390_TSCH 22
/* For KVM_EXIT_INTERNAL_ERROR */
/* Emulate instruction failed. */
@@ -285,6 +286,15 @@
__u64 ret;
__u64 args[9];
} papr_hcall;
+ /* KVM_EXIT_S390_TSCH */
+ struct {
+ __u16 subchannel_id;
+ __u16 subchannel_nr;
+ __u32 io_int_parm;
+ __u32 io_int_word;
+ __u32 ipb;
+ __u8 dequeued;
+ } s390_tsch;
/* Fix the size of the union. */
char padding[256];
};
@@ -645,6 +655,7 @@
#define KVM_CAP_IRQFD_RESAMPLE 82
#define KVM_CAP_PPC_BOOKE_WATCHDOG 83
#define KVM_CAP_PPC_HTAB_FD 84
+#define KVM_CAP_S390_CSS_SUPPORT 85
#ifdef KVM_CAP_IRQ_ROUTING