We will place the request virtqueues in the flexible array member.

Refining the virtqueue API would let us drop the sglist copy, at
which point the pointer-to-array-of-pointers can become a simple
pointer-to-array.  It would both simplify the allocation and remove a
dereference in several hot paths.

Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
 drivers/scsi/virtio_scsi.c |   23 +++++++++++++++--------
 1 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 595af1a..62fec04 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -77,7 +77,7 @@ struct virtio_scsi {
        /* Get some buffers ready for event vq */
        struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
 
-       struct virtio_scsi_target_state *tgt[];
+       struct virtio_scsi_target_state **tgt;
 };
 
 static struct kmem_cache *virtscsi_cmd_cache;
@@ -615,10 +615,13 @@ static void virtscsi_remove_vqs(struct virtio_device 
*vdev)
        /* Stop all the virtqueues. */
        vdev->config->reset(vdev);
 
-       num_targets = sh->max_id;
-       for (i = 0; i < num_targets; i++) {
-               kfree(vscsi->tgt[i]);
-               vscsi->tgt[i] = NULL;
+       if (vscsi->tgt) {
+               num_targets = sh->max_id;
+               for (i = 0; i < num_targets; i++) {
+                       kfree(vscsi->tgt[i]);
+                       vscsi->tgt[i] = NULL;
+               }
+               kfree(vscsi->tgt);
        }
 
        vdev->config->del_vqs(vdev);
@@ -660,6 +663,12 @@ static int virtscsi_init(struct virtio_device *vdev,
        /* We need to know how many segments before we allocate.  */
        sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
 
+       vscsi->tgt = kmalloc(num_targets *
+                       sizeof(struct virtio_scsi_target_state *), GFP_KERNEL);
+       if (!vscsi->tgt) {
+               err = -ENOMEM;
+               goto out;
+       }
        for (i = 0; i < num_targets; i++) {
                vscsi->tgt[i] = virtscsi_alloc_tgt(vdev, sg_elems);
                if (!vscsi->tgt[i]) {
@@ -685,9 +694,7 @@ static int __devinit virtscsi_probe(struct virtio_device 
*vdev)
 
        /* Allocate memory and link the structs together.  */
        num_targets = virtscsi_config_get(vdev, max_target) + 1;
-       shost = scsi_host_alloc(&virtscsi_host_template,
-               sizeof(*vscsi)
-               + num_targets * sizeof(struct virtio_scsi_target_state));
+       shost = scsi_host_alloc(&virtscsi_host_template, sizeof(*vscsi));
 
        if (!shost)
                return -ENOMEM;
-- 
1.7.1


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