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+/*
+ * Copyright (c) 2014 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
+ */
+
+#ifndef __DEV_VIRTIO_BLOCK_HH__
+#define __DEV_VIRTIO_BLOCK_HH__
+
+#include "dev/virtio/base.hh"
+#include "dev/disk_image.hh"
+#include "dev/terminal.hh"
+
+struct VirtIOBlockParams;
+
+/**
+ * VirtIO block device
+ *
+ * The block device uses the following queues:
+ * -# Requests
+ *
+ * A guest issues a request by creating a descriptor chain that starts
+ * with a BlkRequest. Immediately after the BlkRequest follows the
+ * data for the request. The data buffer(s) are either input or output
+ * descriptors depending on the request type. The last byte in the
+ * descriptor chain should always be writable by the host and contains
+ * the request status code (OK/Error).
+ *
+ * The protocol supports asynchronous request completion by returning
+ * descriptor chains when they have been populated by the backing
+ * store. However, there is little point in doing so here.
+ *
+ * @see https://github.com/rustyrussell/virtio-spec
+ * @see http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html
+ */
+class VirtIOBlock : public VirtIODeviceBase
+{
+ public:
+ typedef VirtIOBlockParams Params;
+ VirtIOBlock(Params *params);
+ virtual ~VirtIOBlock();
+
+ void readConfig(PacketPtr pkt, Addr cfgOffset);
+
+ protected:
+ static const DeviceId ID_BLOCK = 0x02;
+
+ /**
+ * Block device configuration structure
+ *
+ * @note This needs to be changed if the supported feature set
+ * changes!
+ */
+ struct Config {
+ uint64_t capacity;
+ } M5_ATTR_PACKED;
+ Config config;
+
+ /** @{
+ * @name Feature bits
+ */
+ static const FeatureBits F_SIZE_MAX = (1 << 1);
+ static const FeatureBits F_SEG_MAX = (1 << 2);
+ static const FeatureBits F_GEOMETRY = (1 << 4);
+ static const FeatureBits F_RO = (1 << 5);
+ static const FeatureBits F_BLK_SIZE = (1 << 6);
+ static const FeatureBits F_TOPOLOGY = (1 << 10);
+ /** @} */
+
+ /** @{
+ * @name VirtIO block requests
+ */
+ typedef uint32_t RequestType;
+ /** Read request */
+ static const RequestType T_IN = 0;
+ /** Write request */
+ static const RequestType T_OUT = 1;
+ /** Flush device buffers */
+ static const RequestType T_FLUSH = 4;
+ /** @} */
+
+ /** @{
+ * @name VirtIO block request status
+ */
+ typedef uint8_t Status;
+ /** Request succeeded */
+ static const Status S_OK = 0;
+ /** Request failed due to a device error */
+ static const Status S_IOERR = 1;
+ /** Request not supported */
+ static const Status S_UNSUPP = 2;
+ /** @} */
+
+ /** VirtIO block device request as sent by guest */
+ struct BlkRequest {
+ RequestType type;
+ uint32_t reserved;
+ uint64_t sector;
+ } M5_ATTR_PACKED;
+
+ /**
+ * Device read request.
+ *
+ * @param req Disk request from guest.
+ * @param desc_chain Request descriptor chain (from start of
+ * request)
+ * @param off_data Offset into the descriptor chain where data
+ * should be written.
+ * @param size Request data size.
+ */
+ Status read(const BlkRequest &req, VirtDescriptor *desc_chain,
+ size_t off_data, size_t size);
+ /**
+ * Device write request.
+ *
+ * @param req Disk request from guest.
+ * @param desc_chain Request descriptor chain (from start of
+ * request)
+ * @param off_data Offset into the descriptor chain where data
+ * should be read.
+ * @param size Request data size.
+ */
+ Status write(const BlkRequest &req, VirtDescriptor *desc_chain,
+ size_t off_data, size_t size);
+
+ protected:
+ /**
+ * Virtqueue for disk requests.
+ */
+ class RequestQueue
+ : public VirtQueue
+ {
+ public:
+ RequestQueue(PortProxy &proxy, uint16_t size, VirtIOBlock &_parent)
+ : VirtQueue(proxy, size), parent(_parent) {}
+ virtual ~RequestQueue() {}
+
+ void onNotifyDescriptor(VirtDescriptor *desc);
+
+ std::string name() const { return parent.name() + ".qRequests"; }
+
+ protected:
+ VirtIOBlock &parent;
+ };
+
+ /** Device I/O request queue */
+ RequestQueue qRequests;
+
+ /** Image backing this device */
+ DiskImage &image;
+};
+
+#endif // __DEV_VIRTIO_BLOCK_HH__