Commit 0d8d769085 introduced
a regression in virtio-net performance because it looks
into the ring aggressively while we really only care
about a single packet worth of buffers.
Reported as bugzilla 1066055 in launchpad.
To fix, add parameters limiting lookahead, and
use in virtqueue_avail_bytes.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reported-by: Edivaldo de Araujo Pereira <edivaldoapereira@yahoo.com.br>
Tested-by: Edivaldo de Araujo Pereira <edivaldoapereira@yahoo.com.br>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
g_assert_cmpint is not available on glib 2.12, which is the minimum
version required to build QEMU (we only require 2.16 to run tests,
since that is the first version including GTester). Do not use it
in hardware models, use a normal assertion instead.
This fixes the buildbot failure for default_x86_64_rhel5.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Fix typos, whitespace and update comments to match current
implementation.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Disable the rate-limit timer on device remove (e.g. hot-unplug).
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
If we got fewer bytes from the backend than requested, don't poke the
backend for more bytes; the guest will ask for more (or if the guest has
already asked for more, the backend knows about it via handle_input()).
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Popping an elem from the vq just to find out its length causes problems
with save/load later on. Use the new virtqueue_get_avail_bytes()
function instead, saves us the complexity in the migration code, as well
as makes the migration endian-safe.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
The Linux kernel already has a virtio-rng driver, this is the device
implementation.
When the guest asks for entropy from the virtio hwrng, it puts a buffer
in the vq. We then put entropy into that buffer, and push it back to
the guest.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
aliguori: converted to new RngBackend interface
aliguori: remove entropy needed event
aliguori: fix migration
Paolo Bonzini