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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/storage/disk_image.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 ℑ
};
#endif // __DEV_VIRTIO_BLOCK_HH__
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