virtio-rng: add rate limiting support

This adds parameters to virtio-rng-pci to allow rate limiting the entropy a
guest receives.  An example command line:

$ qemu -device virtio-rng-pci,max-bytes=1024,period=1000

Would limit entropy collection to 1Kb/s.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/hw/virtio-rng.h b/hw/virtio-rng.h
index fbb0104..7324d0a 100644
--- a/hw/virtio-rng.h
+++ b/hw/virtio-rng.h
@@ -19,6 +19,8 @@
 
 struct VirtIORNGConf {
     RngBackend *rng;
+    uint64_t max_bytes;
+    uint32_t period_ms;
 };
 
 #endif