KVM: s390: virtio-ccw revision 1 SET_VQ

The CCW_CMD_SET_VQ command has a different format for revision 1+
devices, allowing to specify a more complex virtqueue layout. For
now, we stay however with the old layout and simply use the new
command format for virtio-1 devices.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>

1 files changed, 42 insertions, 12 deletions

diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index f6eb47b4775b..1c21c08f33be 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -68,13 +68,22 @@ struct virtio_ccw_device {
         void *airq_info;
 };
 
-struct vq_info_block {
+struct vq_info_block_legacy {
         __u64 queue;
         __u32 align;
         __u16 index;
         __u16 num;
 } __packed;
 
+struct vq_info_block {
+        __u64 desc;
+        __u32 res0;
+        __u16 index;
+        __u16 num;
+        __u64 avail;
+        __u64 used;
+} __packed;
+
 struct virtio_feature_desc {
         __u32 features;
         __u8 index;
@@ -100,7 +109,10 @@ struct virtio_ccw_vq_info {
         struct virtqueue *vq;
         int num;
         void *queue;
-        struct vq_info_block *info_block;
+        union {
+                struct vq_info_block s;
+                struct vq_info_block_legacy l;
+        } *info_block;
         int bit_nr;
         struct list_head node;
         long cookie;
@@ -411,13 +423,22 @@ static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
         spin_unlock_irqrestore(&vcdev->lock, flags);
 
         /* Release from host. */
-        info->info_block->queue = 0;
-        info->info_block->align = 0;
-        info->info_block->index = index;
-        info->info_block->num = 0;
+        if (vcdev->revision == 0) {
+                info->info_block->l.queue = 0;
+                info->info_block->l.align = 0;
+                info->info_block->l.index = index;
+                info->info_block->l.num = 0;
+                ccw->count = sizeof(info->info_block->l);
+        } else {
+                info->info_block->s.desc = 0;
+                info->info_block->s.index = index;
+                info->info_block->s.num = 0;
+                info->info_block->s.avail = 0;
+                info->info_block->s.used = 0;
+                ccw->count = sizeof(info->info_block->s);
+        }
         ccw->cmd_code = CCW_CMD_SET_VQ;
         ccw->flags = 0;
-        ccw->count = sizeof(*info->info_block);
         ccw->cda = (__u32)(unsigned long)(info->info_block);
         ret = ccw_io_helper(vcdev, ccw,
                             VIRTIO_CCW_DOING_SET_VQ | index);
@@ -500,13 +521,22 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
         }
 
         /* Register it with the host. */
-        info->info_block->queue = (__u64)info->queue;
-        info->info_block->align = KVM_VIRTIO_CCW_RING_ALIGN;
-        info->info_block->index = i;
-        info->info_block->num = info->num;
+        if (vcdev->revision == 0) {
+                info->info_block->l.queue = (__u64)info->queue;
+                info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
+                info->info_block->l.index = i;
+                info->info_block->l.num = info->num;
+                ccw->count = sizeof(info->info_block->l);
+        } else {
+                info->info_block->s.desc = (__u64)info->queue;
+                info->info_block->s.index = i;
+                info->info_block->s.num = info->num;
+                info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
+                info->info_block->s.used = (__u64)virtqueue_get_used(vq);
+                ccw->count = sizeof(info->info_block->s);
+        }
         ccw->cmd_code = CCW_CMD_SET_VQ;
         ccw->flags = 0;
-        ccw->count = sizeof(*info->info_block);
         ccw->cda = (__u32)(unsigned long)(info->info_block);
         err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
         if (err) {