debian/patches/0005-virtio-rng-ask-for-more-data-if-queue-is-not-fully-d.patch

   1 From b5f29c3cdd14243de19d974320f49fb3bdd37a6d Mon Sep 17 00:00:00 2001
   2 From: Ladi Prosek <lprosek@redhat.com>
   3 Date: Thu, 3 Mar 2016 10:48:34 +0100
   4 Subject: [PATCH 5/5] virtio-rng: ask for more data if queue is not fully
   5  drained
   6
   7 This commit effectively reverts:
   8
   9   commit 4621c1768ef5d12171cca2aa1473595ecb9f1c9e
  10   Author: Amit Shah <amit.shah@redhat.com>
  11   Date:   Wed Nov 21 11:21:19 2012 +0530
  12
  13   virtio-rng: remove extra request for entropy
  14
  15 but instead of calling virtio_rng_process unconditionally, it
  16 first checks to see if the queue is empty as a little bit of
  17 optimization.
  18
  19 Signed-off-by: Ladi Prosek <lprosek@redhat.com>
  20 Reviewed-by: Amit Shah <amit.shah@redhat.com>
  21 Message-Id: <1456998514-19271-1-git-send-email-lprosek@redhat.com>
  22 Signed-off-by: Amit Shah <amit.shah@redhat.com>
  23 ---
  24  hw/virtio/virtio-rng.c | 7 +++++++
  25  1 file changed, 7 insertions(+)
  26
  27 diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c
  28 index 97d1541..3124461 100644
  29 --- a/hw/virtio/virtio-rng.c
  30 +++ b/hw/virtio/virtio-rng.c
  31 @@ -66,6 +66,13 @@ static void chr_read(void *opaque, const void *buf, size_t size)
  32          trace_virtio_rng_pushed(vrng, len);
  33      }
  34      virtio_notify(vdev, vrng->vq);
  35 +
  36 +    if (!virtio_queue_empty(vrng->vq)) {
  37 +        /* If we didn't drain the queue, call virtio_rng_process
  38 +         * to take care of asking for more data as appropriate.
  39 +         */
  40 +        virtio_rng_process(vrng);
  41 +    }
  42  }
  43
  44  static void virtio_rng_process(VirtIORNG *vrng)
  45 --
  46 2.1.4
  47