f67ff25f7b
Systemd, which is used by many main stream Linux distributions, will lead to slow boot if entropy is low. On X86 platforms, this problem can be alleviated by enabling RDRAND instructions. However, RISC-V doesn't have similar instructions. For QEMU/KVM, this problem can be solved by passing randomness from the host via virtio_rng. But gem5 doesn't have VirtIORng support now. Some user report that the boot time of riscv-ubuntu-run.py is too long. To alleviate this problem, this patch add VirtIORng device support for gem5. Change-Id: Id93b5703161701212fd6683837034cb0cff590c5 Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/55483 Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu> Maintainer: Bobby Bruce <bbruce@ucdavis.edu> Tested-by: kokoro <noreply+kokoro@google.com>
107 lines
3.6 KiB
C++
107 lines
3.6 KiB
C++
/*
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* Copyright (c) 2022 Institute of Computing Technology, Chinese Academy
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* of Sciences
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* All rights reserved
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*
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* The license below extends only to copyright in the software and shall
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* not be construed as granting a license to any other intellectual
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* property including but not limited to intellectual property relating
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* to a hardware implementation of the functionality of the software
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* licensed hereunder. You may use the software subject to the license
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* terms below provided that you ensure that this notice is replicated
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* unmodified and in its entirety in all distributions of the software,
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* modified or unmodified, in source code or in binary form.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met: redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer;
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* redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution;
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* neither the name of the copyright holders nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef __DEV_VIRTIO_RNG_HH__
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#define __DEV_VIRTIO_RNG_HH__
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#include <random>
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#include "base/compiler.hh"
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#include "dev/virtio/base.hh"
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namespace gem5
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{
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struct VirtIORngParams;
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/**
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* VirtIO Rng
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*
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* @see https://github.com/rustyrussell/virtio-spec
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* @see http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html
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*/
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class VirtIORng : public VirtIODeviceBase
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{
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public:
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typedef VirtIORngParams Params;
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VirtIORng(const Params ¶ms);
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virtual ~VirtIORng();
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void readConfig(PacketPtr pkt, Addr cfgOffset);
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protected:
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/** VirtIO device ID */
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static const DeviceId ID_RNG = 0x04;
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protected:
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/**
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* Virtqueue for data going from the host to the guest.
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*/
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class RngQueue
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: public VirtQueue
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{
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public:
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RngQueue(PortProxy &proxy, ByteOrder bo,
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uint16_t size, const std::string &rng_file_path,
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VirtIORng &_parent);
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virtual ~RngQueue() {}
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void onNotify() { trySend(); }
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/** Try to send data pending data from the terminal. */
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void trySend();
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std::string name() const { return parent.name() + ".qRecv"; }
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protected:
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VirtIORng &parent;
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private:
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// system's special file for generating random number
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int rng_fd;
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// fallback random number generator
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std::random_device rd_device;
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std::uniform_int_distribution<int> dist;
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};
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/** Receive queue for port 0 */
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RngQueue qReq;
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};
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} // namespace gem5
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#endif // __DEV_VIRTIO_RNG_HH__
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