arch-riscv, dev: add VirtIO entropy device(VirtIORng) support
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>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/56245
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
diff --git a/configs/example/riscv/fs_linux.py b/configs/example/riscv/fs_linux.py
index 2947c1e..570ef22 100644
--- a/configs/example/riscv/fs_linux.py
+++ b/configs/example/riscv/fs_linux.py
@@ -75,6 +75,7 @@
# linux kernel payload)
# --disk-image (optional): Path to disk image file. Not needed if using
# ramfs (might run into issues though).
+# --virtio-rng (optional): Enable VirtIO entropy source device
# --command-line (optional): Specify to override default.
# --dtb-filename (optional): Path to DTB file. Auto-generated if empty.
# --bare-metal (boolean): Use baremetal Riscv (default False). Use this
@@ -129,6 +130,8 @@
parser.add_argument("--dtb-filename", action="store", type=str,
help="Specifies device tree blob file to use with device-tree-"\
"enabled kernels")
+parser.add_argument("--virtio-rng", action="store_true",
+ help="Enable VirtIORng device")
# ---------------------------- Parse Options --------------------------- #
args = parser.parse_args()
@@ -177,6 +180,15 @@
pio_addr=0x10008000
)
+# VirtIORng
+if args.virtio_rng:
+ system.platform.rng = RiscvMmioVirtIO(
+ vio=VirtIORng(),
+ interrupt_id=0x8,
+ pio_size=4096,
+ pio_addr=0x10007000
+ )
+
system.bridge = Bridge(delay='50ns')
system.bridge.mem_side_port = system.iobus.cpu_side_ports
system.bridge.cpu_side_port = system.membus.mem_side_ports
diff --git a/src/dev/riscv/HiFive.py b/src/dev/riscv/HiFive.py
index 2923b88..a76e456 100755
--- a/src/dev/riscv/HiFive.py
+++ b/src/dev/riscv/HiFive.py
@@ -126,6 +126,8 @@
devices = [self.uart]
if hasattr(self, "disk"):
devices.append(self.disk)
+ if hasattr(self, "rng"):
+ devices.append(self.rng)
return devices
def _on_chip_ranges(self):
diff --git a/src/dev/virtio/SConscript b/src/dev/virtio/SConscript
index bf083e7..b00679c 100644
--- a/src/dev/virtio/SConscript
+++ b/src/dev/virtio/SConscript
@@ -44,6 +44,7 @@
'VirtIODeviceBase', 'VirtIODummyDevice', 'PciVirtIO'])
SimObject('VirtIOConsole.py', sim_objects=['VirtIOConsole'])
SimObject('VirtIOBlock.py', sim_objects=['VirtIOBlock'])
+SimObject('VirtIORng.py', sim_objects=['VirtIORng'])
SimObject('VirtIO9P.py', sim_objects=[
'VirtIO9PBase', 'VirtIO9PProxy', 'VirtIO9PDiod', 'VirtIO9PSocket'])
@@ -52,8 +53,10 @@
Source('console.cc')
Source('block.cc')
Source('fs9p.cc')
+Source('rng.cc')
DebugFlag('VIO', 'VirtIO base functionality')
+DebugFlag('VIORng', 'VirtIO entropy source device ')
DebugFlag('VIOIface', 'VirtIO transport')
DebugFlag('VIOConsole', 'VirtIO console device')
DebugFlag('VIOBlock', 'VirtIO block device')
diff --git a/src/dev/virtio/VirtIORng.py b/src/dev/virtio/VirtIORng.py
new file mode 100644
index 0000000..54848ee
--- /dev/null
+++ b/src/dev/virtio/VirtIORng.py
@@ -0,0 +1,50 @@
+# -*- mode:python -*-
+
+# Copyright (c) 2022 Institute of Computing Technology, Chinese
+# Academy of Sciences
+# All rights reserved.
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder. You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from m5.params import *
+from m5.proxy import *
+from m5.objects.VirtIO import VirtIODeviceBase
+
+class VirtIORng(VirtIODeviceBase):
+ type = 'VirtIORng'
+ cxx_header = 'dev/virtio/rng.hh'
+ cxx_class = 'gem5::VirtIORng'
+
+ qSize = Param.Unsigned(16, "Request queue size")
+
+ entropy_source = Param.String("/dev/random", "The source of entropy")
diff --git a/src/dev/virtio/rng.cc b/src/dev/virtio/rng.cc
new file mode 100644
index 0000000..50a747c
--- /dev/null
+++ b/src/dev/virtio/rng.cc
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2022 Institute of Computing Technology, Chinese Academy
+ * of Sciences
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder. You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "dev/virtio/rng.hh"
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "debug/VIORng.hh"
+#include "params/VirtIORng.hh"
+#include "sim/system.hh"
+
+namespace gem5
+{
+
+VirtIORng::VirtIORng(const Params ¶ms)
+ : VirtIODeviceBase(params, ID_RNG, 0, 0),
+ qReq(params.system->physProxy, byteOrder, params.qSize,
+ params.entropy_source, *this)
+{
+ registerQueue(qReq);
+}
+
+VirtIORng::~VirtIORng()
+{
+}
+
+VirtIORng::RngQueue::RngQueue(PortProxy &proxy, ByteOrder bo,
+ uint16_t size, const std::string &rng_file_path,
+ VirtIORng &_parent)
+ : VirtQueue(proxy, bo, size), parent(_parent), dist(0,255)
+{
+ rng_fd = open(rng_file_path.c_str(), O_RDONLY);
+ if (rng_fd < 0) {
+ DPRINTF(VIORng, "error when open entropy source: %s\n",
+ rng_file_path.c_str());
+ }
+}
+
+void
+VirtIORng::readConfig(PacketPtr pkt, Addr cfgOffset)
+{
+ // There are no configuration for RNG device
+ pkt->makeResponse();
+}
+
+void
+VirtIORng::RngQueue::trySend()
+{
+ DPRINTF(VIORng, "try send\n");
+
+ VirtDescriptor *d;
+ while ((d = consumeDescriptor())) {
+ DPRINTF(VIORng, "Got descriptor (len: %i)\n", d->size());
+ size_t len = 0;
+ while (len < d->size()) {
+ uint8_t byte = 0;
+ bool rng_read_success = false;
+ if (rng_fd >= 0) {
+ ssize_t result = read(rng_fd, &byte, sizeof(uint8_t));
+ rng_read_success = (result > 0);
+ }
+ if (!rng_read_success) {
+ // fallback to C++ std rng generator
+ byte = dist(rd_device);
+ }
+ d->chainWrite(len, &byte, sizeof(uint8_t));
+ ++len;
+ }
+
+ // Tell the guest that we are done with this descriptor.
+ produceDescriptor(d, len);
+ parent.kick();
+ }
+}
+
+} // namespace gem5
diff --git a/src/dev/virtio/rng.hh b/src/dev/virtio/rng.hh
new file mode 100644
index 0000000..50a3723
--- /dev/null
+++ b/src/dev/virtio/rng.hh
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2022 Institute of Computing Technology, Chinese Academy
+ * of Sciences
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder. You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __DEV_VIRTIO_RNG_HH__
+#define __DEV_VIRTIO_RNG_HH__
+
+#include <random>
+
+#include "base/compiler.hh"
+#include "dev/virtio/base.hh"
+
+namespace gem5
+{
+
+struct VirtIORngParams;
+
+/**
+ * VirtIO Rng
+ *
+ * @see https://github.com/rustyrussell/virtio-spec
+ * @see http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html
+ */
+class VirtIORng : public VirtIODeviceBase
+{
+ public:
+ typedef VirtIORngParams Params;
+ VirtIORng(const Params ¶ms);
+ virtual ~VirtIORng();
+
+ void readConfig(PacketPtr pkt, Addr cfgOffset);
+
+ protected:
+ /** VirtIO device ID */
+ static const DeviceId ID_RNG = 0x04;
+
+ protected:
+ /**
+ * Virtqueue for data going from the host to the guest.
+ */
+ class RngQueue
+ : public VirtQueue
+ {
+ public:
+ RngQueue(PortProxy &proxy, ByteOrder bo,
+ uint16_t size, const std::string &rng_file_path,
+ VirtIORng &_parent);
+ virtual ~RngQueue() {}
+
+ void onNotify() { trySend(); }
+
+ /** Try to send data pending data from the terminal. */
+ void trySend();
+
+ std::string name() const { return parent.name() + ".qRecv"; }
+
+ protected:
+ VirtIORng &parent;
+ private:
+ // system's special file for generating random number
+ int rng_fd;
+ // fallback random number generator
+ std::random_device rd_device;
+ std::uniform_int_distribution<int> dist;
+ };
+ /** Receive queue for port 0 */
+ RngQueue qReq;
+};
+
+} // namespace gem5
+
+#endif // __DEV_VIRTIO_RNG_HH__
diff --git a/src/python/gem5/components/boards/riscv_board.py b/src/python/gem5/components/boards/riscv_board.py
index 7c5b547..7dfa9db 100644
--- a/src/python/gem5/components/boards/riscv_board.py
+++ b/src/python/gem5/components/boards/riscv_board.py
@@ -54,6 +54,7 @@
RawDiskImage,
RiscvMmioVirtIO,
VirtIOBlock,
+ VirtIORng,
Frequency,
Port,
)
@@ -119,10 +120,18 @@
pio_addr=0x10008000,
)
+ # The virtio rng
+ self.rng = RiscvMmioVirtIO(
+ vio=VirtIORng(),
+ interrupt_id=0x8,
+ pio_size=4096,
+ pio_addr=0x10007000,
+ )
+
# Note: This overrides the platform's code because the platform isn't
# general enough.
self._on_chip_devices = [self.platform.clint, self.platform.plic]
- self._off_chip_devices = [self.platform.uart, self.disk]
+ self._off_chip_devices = [self.platform.uart, self.disk, self.rng]
def _setup_io_devices(self) -> None:
"""Connect the I/O devices to the I/O bus"""
@@ -337,6 +346,18 @@
disk_node.appendCompatible(["virtio,mmio"])
soc_node.append(disk_node)
+ # VirtIO MMIO rng node
+ rng = self.rng
+ rng_node = rng.generateBasicPioDeviceNode(
+ soc_state, "virtio_mmio", rng.pio_addr, rng.pio_size
+ )
+ rng_node.append(FdtPropertyWords("interrupts", [rng.interrupt_id]))
+ rng_node.append(
+ FdtPropertyWords("interrupt-parent", soc_state.phandle(plic))
+ )
+ rng_node.appendCompatible(["virtio,mmio"])
+ soc_node.append(rng_node)
+
root.append(soc_node)
fdt = Fdt()
