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From:   Laurent Vivier <lvivier@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     amit@kernel.org, Herbert Xu <herbert@gondor.apana.org.au>,
        Matt Mackall <mpm@selenic.com>,
        virtualization@lists.linux-foundation.org,
        Dmitriy Vyukov <dvyukov@google.com>, rusty@rustcorp.com.au,
        akong@redhat.com, Alexander Potapenko <glider@google.com>,
        "Michael S . Tsirkin" <mst@redhat.com>,
        linux-crypto@vger.kernel.org, Laurent Vivier <lvivier@redhat.com>
Subject: [PATCH v2 0/4] hwrng: virtio - add an internal buffer
Date:   Thu, 28 Oct 2021 12:11:07 +0200
Message-Id: <20211028101111.128049-1-lvivier@redhat.com>
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hwrng core uses two buffers that can be mixed in the virtio-rng queue.=0D
=0D
This series fixes the problem by adding an internal buffer in virtio-rng.=0D
=0D
Once the internal buffer is added, we can fix two other problems:=0D
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- to be able to release the driver without waiting the device releases the=
=0D
  buffer=0D
=0D
- actually returns some data when wait=3D0 as we can have some already=0D
  available data=0D
=0D
It also tries to improve the performance by always having a buffer in=0D
the queue of the device.=0D
=0D
v2:=0D
fixes issue reported by syzbot+b86736b5935e0d25b446@syzkaller.appspotmail.c=
om=0D
by reseting data_idx to 0 when the buffer is submitted not when it is=0D
received as the consumer checks for data_avail, not only for the completion=
.=0D
=0D
Laurent Vivier (4):=0D
  hwrng: virtio - add an internal buffer=0D
  hwrng: virtio - don't wait on cleanup=0D
  hwrng: virtio - don't waste entropy=0D
  hwrng: virtio - always add a pending request=0D
=0D
 drivers/char/hw_random/virtio-rng.c | 86 ++++++++++++++++++++++-------=0D
 1 file changed, 65 insertions(+), 21 deletions(-)=0D
=0D
-- =0D
2.31.1=0D
=0D