s390: Add a hypercall registration interface.

Allow virtio machines to register for different diag500 function
codes and convert s390-virtio to use it.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

2 files changed, 37 insertions, 0 deletions

diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
index 4a5a5d8..1b40c2e 100644
--- a/hw/s390x/Makefile.objs
+++ b/hw/s390x/Makefile.objs
@@ -1,6 +1,7 @@
 obj-y = s390-virtio-bus.o s390-virtio.o
 
 obj-y := $(addprefix ../,$(obj-y))
+obj-y += s390-virtio-hcall.o
 obj-y += sclp.o
 obj-y += event-facility.o
 obj-y += sclpquiesce.o sclpconsole.o
diff --git a/hw/s390x/s390-virtio-hcall.c b/hw/s390x/s390-virtio-hcall.c
new file mode 100644
index 0000000..d7938c0
--- /dev/null
+++ b/hw/s390x/s390-virtio-hcall.c
@@ -0,0 +1,36 @@
+/*
+ * Support for virtio hypercalls on s390
+ *
+ * Copyright 2012 IBM Corp.
+ * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include "cpu.h"
+#include "hw/s390-virtio.h"
+
+#define MAX_DIAG_SUBCODES 255
+
+static s390_virtio_fn s390_diag500_table[MAX_DIAG_SUBCODES];
+
+void s390_register_virtio_hypercall(uint64_t code, s390_virtio_fn fn)
+{
+    assert(code < MAX_DIAG_SUBCODES);
+    assert(!s390_diag500_table[code]);
+
+    s390_diag500_table[code] = fn;
+}
+
+int s390_virtio_hypercall(CPUS390XState *env)
+{
+    s390_virtio_fn fn = s390_diag500_table[env->regs[1]];
+
+    if (!fn) {
+        return -EINVAL;
+    }
+
+    return fn(&env->regs[2]);
+}