virtio: find_vqs/del_vqs virtio operations

This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations,
and updates all drivers. This is needed for MSI support, because MSI
needs to know the total number of vectors upfront.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)

1 files changed, 34 insertions, 2 deletions

diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index ba8995fbf041..e38e5d306faf 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -227,6 +227,38 @@ static void kvm_del_vq(struct virtqueue *vq)
                                        KVM_S390_VIRTIO_RING_ALIGN));
 }
 
+static void kvm_del_vqs(struct virtio_device *vdev)
+{
+        struct virtqueue *vq, *n;
+
+        list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+                kvm_del_vq(vq);
+}
+
+static int kvm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+                        struct virtqueue *vqs[],
+                        vq_callback_t *callbacks[],
+                        const char *names[])
+{
+        struct kvm_device *kdev = to_kvmdev(vdev);
+        int i;
+
+        /* We must have this many virtqueues. */
+        if (nvqs > kdev->desc->num_vq)
+                return -ENOENT;
+
+        for (i = 0; i < nvqs; ++i) {
+                vqs[i] = kvm_find_vq(vdev, i, callbacks[i], names[i]);
+                if (IS_ERR(vqs[i]))
+                        goto error;
+        }
+        return 0;
+
+error:
+        kvm_del_vqs(vdev);
+        return PTR_ERR(vqs[i]);
+}
+
 /*
  * The config ops structure as defined by virtio config
  */
@@ -238,8 +270,8 @@ static struct virtio_config_ops kvm_vq_configspace_ops = {
         .get_status = kvm_get_status,
         .set_status = kvm_set_status,
         .reset = kvm_reset,
-        .find_vq = kvm_find_vq,
-        .del_vq = kvm_del_vq,
+        .find_vqs = kvm_find_vqs,
+        .del_vqs = kvm_del_vqs,
 };
 
 /*