dev-arm: Add a MMIO transport interface for VirtIO

The MMIO interface currently only supports a subset of version 0.9.5
of the VirtIO specification. It has the following known limitations:

  * The queue size hint (the QUEUE_NUM register) is ignored.

  * Queue alignment is assumed to be hard-coded to
    VirtQueue::ALIGN_SIZE (4096 bytes).

  * Only 4096 byte pages are currently supported.

Change-Id: Ifd318f5e5bddab0b6a42d8c8af9ff2fbb477f98b
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Rekai Gonzalez Alberquilla <rekai.gonzalezalberquilla@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2326
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/src/dev/arm/VirtIOMMIO.py b/src/dev/arm/VirtIOMMIO.py
new file mode 100644
index 000000000..2c95ef3ce
--- /dev/null
+++ b/src/dev/arm/VirtIOMMIO.py
@@ -0,0 +1,63 @@
+# -*- mode:python -*-
+
+# Copyright (c) 2014, 2016-2018 ARM Limited
+# 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.
+#
+# Authors: Andreas Sandberg
+
+from m5.SimObject import SimObject
+from m5.params import *
+from m5.proxy import *
+
+from Device import BasicPioDevice
+from Gic import ArmInterruptPin
+from VirtIO import VirtIODeviceBase, VirtIODummyDevice
+
+class MmioVirtIO(BasicPioDevice):
+    type = 'MmioVirtIO'
+    cxx_header = 'dev/arm/vio_mmio.hh'
+
+    pio_size = Param.Addr(4096, "IO range")
+    interrupt = Param.ArmInterruptPin("Interrupt to use for this device")
+
+    vio = Param.VirtIODeviceBase(VirtIODummyDevice(), "VirtIO device")
+
+    def generateDeviceTree(self, state):
+        node = self.generateBasicPioDeviceNode(state, 'virtio', self.pio_addr,
+                                               int(self.pio_size), [
+                                                   int(self.interrupt.num),
+                                               ])
+        node.appendCompatible(["virtio,mmio"])
+        yield node