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Diffstat (limited to 'pc-bios/s390-ccw/virtio.c')
-rw-r--r--pc-bios/s390-ccw/virtio.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index f438af15aa..49f2d291fc 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -13,6 +13,8 @@
struct vring block;
+static char chsc_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
+
static long kvm_hypercall(unsigned long nr, unsigned long param1,
unsigned long param2)
{
@@ -301,3 +303,19 @@ bool virtio_is_blk(struct subchannel_id schid)
return true;
}
+int enable_mss_facility(void)
+{
+ int ret;
+ struct chsc_area_sda *sda_area = (struct chsc_area_sda *) chsc_page;
+
+ memset(sda_area, 0, PAGE_SIZE);
+ sda_area->request.length = 0x0400;
+ sda_area->request.code = 0x0031;
+ sda_area->operation_code = 0x2;
+
+ ret = chsc(sda_area);
+ if ((ret == 0) && (sda_area->response.code == 0x0001)) {
+ return 0;
+ }
+ return -EIO;
+}