[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Qemu-devel] [PATCH] virtio-rng: ask for more data if queue is not fully

From: Ladi Prosek
Subject: [Qemu-devel] [PATCH] virtio-rng: ask for more data if queue is not fully drained
Date: Thu, 3 Mar 2016 10:48:34 +0100

This commit effectively reverts:

  commit 4621c1768ef5d12171cca2aa1473595ecb9f1c9e
  Author: Amit Shah <address@hidden>
  Date:   Wed Nov 21 11:21:19 2012 +0530

  virtio-rng: remove extra request for entropy

but instead of calling virtio_rng_process unconditionally, it
first checks to see if the queue is empty as a little bit of

Signed-off-by: Ladi Prosek <address@hidden>
This commit has a logical dependency on

[PATCH v3 0/4] rng-random: implement request queue

which removes a synchronous invocation of the receive_func callback in
rng_random_request_entropy, thereby eliminating the risk of infinite

 hw/virtio/virtio-rng.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c
index 17da2f8..d713464 100644
--- a/hw/virtio/virtio-rng.c
+++ b/hw/virtio/virtio-rng.c
@@ -69,6 +69,13 @@ static void chr_read(void *opaque, const void *buf, size_t 
     virtio_notify(vdev, vrng->vq);
+    if (!virtio_queue_empty(vrng->vq)) {
+        /* If we didn't drain the queue, call virtio_rng_process
+         * to take care of asking for more data as appropriate.
+         */
+        virtio_rng_process(vrng);
+    }
 static void virtio_rng_process(VirtIORNG *vrng)

reply via email to

[Prev in Thread] Current Thread [Next in Thread]