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/*
* Copyright (c) 2014-2017 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_FS9P_HH__
#define __DEV_VIRTIO_FS9P_HH__
#include <map>
#include <memory>
#include <string>
#include "base/pollevent.hh"
#include "dev/virtio/base.hh"
struct VirtIO9PBaseParams;
typedef uint8_t P9MsgType;
typedef uint16_t P9Tag;
struct P9MsgHeader {
/** Length including header */
uint32_t len;
/** Message type */
P9MsgType type;
/** Message tag */
P9Tag tag;
} M5_ATTR_PACKED;
/** Convert p9 byte order (LE) to host byte order */
template <typename T> inline T
p9toh(T v) { return letoh(v); }
/** Convert host byte order to p9 byte order (LE) */
template <typename T> inline T
htop9(T v) { return htole(v); }
template <> inline P9MsgHeader
p9toh(P9MsgHeader v)
{
v.len = p9toh(v.len);
v.type = p9toh(v.type);
v.tag = p9toh(v.tag);
return v;
}
template <> inline P9MsgHeader
htop9(P9MsgHeader v)
{
v.len = htop9(v.len);
v.type = htop9(v.type);
v.tag = htop9(v.tag);
return v;
}
/**
* This class implements a VirtIO transport layer for the 9p network
* file system.
*
* The 9p VirtIO transport uses the following queues:
* -# 9p requests and replies
*
* Each 9p request and response is sent in its own descriptor
* chain. The guest initiates a transaction by packing a T message
* (see the 9p spec) into the first part of a descriptor chain. After
* the T message, the guest reserves space for the reply (R message)
* by including one or more writable descriptors. The server replies
* by writing an R message into the writable descriptors and putting
* the chain in the used ring (VirtQueue::produceDescriptor()).
*
* @see https://github.com/rustyrussell/virtio-spec
* @see https://github.com/ericvh/9p-rfc
* @see https://code.google.com/p/diod/wiki/protocol
*/
class VirtIO9PBase : public VirtIODeviceBase
{
public:
typedef VirtIO9PBaseParams Params;
VirtIO9PBase(Params *params);
virtual ~VirtIO9PBase();
void readConfig(PacketPtr pkt, Addr cfgOffset);
protected:
/**
* VirtIO 9p configuration structure
*
* @note The fields in this structure depend on the features
* exposed to the guest.
*/
struct Config {
uint16_t len;
char tag[];
} M5_ATTR_PACKED;
/** Currently active configuration (host byte order) */
std::unique_ptr<Config> config;
/** VirtIO device ID */
static const DeviceId ID_9P = 0x09;
/** @{
* @name Feature bits
*/
/** Device provides a name of the resource in its configuration */
static const FeatureBits F_MOUNT_TAG = 0x01;
/** @} */
protected:
/**
* Virtqueue for 9p requests
*/
class FSQueue : public VirtQueue
{
public:
FSQueue(PortProxy &proxy, uint16_t size, VirtIO9PBase &_parent)
: VirtQueue(proxy, size), parent(_parent) {}
virtual ~FSQueue() {}
void onNotifyDescriptor(VirtDescriptor *desc);
std::string name() const { return parent.name() + ".queue"; }
protected:
VirtIO9PBase &parent;
};
FSQueue queue;
protected:
/**
* Handle incoming 9p RPC message.
*
* @param header 9p message header.
* @param data Pointer to data in message.
* @param size Size of data (excluding header)
*/
virtual void recvTMsg(const P9MsgHeader &header, const uint8_t *data, size_t size) = 0;
/**
* Send a 9p RPC message reply.
*
* @param header 9p message header.
* @param data Pointer to data in message.
* @param size Size of data (excluding header)
*/
void sendRMsg(const P9MsgHeader &header, const uint8_t *data, size_t size);
/**
* Dump a 9p RPC message on the debug output
*
* @param header 9p message header.
* @param data Pointer to data in message.
* @param size Size of data (excluding header)
*/
void dumpMsg(const P9MsgHeader &header, const uint8_t *data, size_t size);
private:
/**
* Map between 9p transaction tags and descriptors where they
* appeared.
*
* When handling asynchronous requests, we need to ensure that
* replies are posted in the same descriptor as queries. The 9p
* RPC protocol uses the tag field in the header to match requests
* and replies, which we use here to find the relevant descriptor.
*/
std::map<P9Tag, VirtDescriptor *> pendingTransactions;
};
struct VirtIO9PProxyParams;
/**
* VirtIO 9p proxy base class.
*
* This base class provides basic functionality shared by different 9p
* proxy implementations.
*/
class VirtIO9PProxy : public VirtIO9PBase
{
public:
typedef VirtIO9PProxyParams Params;
VirtIO9PProxy(Params *params);
virtual ~VirtIO9PProxy();
void serialize(CheckpointOut &cp) const override;
void unserialize(CheckpointIn &cp) override;
protected:
void recvTMsg(const P9MsgHeader &header, const uint8_t *data,
size_t size) override;
/** Notification of pending data from server */
void serverDataReady();
/**
* Read data from the server behind the proxy.
*
* @note This method may return read fewer than len bytes.
*
* @param data Memory location to store results in.
* @param len Maximum length to read.
* @return Number of bytes read, -errno on failure.
*/
virtual ssize_t read(uint8_t *data, size_t len) = 0;
/**
* Write data to the server behind the proxy.
*
* @note This method may return write fewer than len bytes.
*
* @param data Pointer to data to write.
* @param len Maximum length to write.
* @return Number of bytes written, -errno on failure.
*/
virtual ssize_t write(const uint8_t *data, size_t len) = 0;
/**
* Convenience function that reads exactly len bytes.
*
* This method calls read until exactly len number of bytes has
* been read. A read() call is retried if the underlying syscall
* was interrupted.
*
* @param data Memory location to store results in.
* @param len Number of bytes to read.
*/
void readAll(uint8_t *data, size_t len);
/**
* Convenience function that writes exactly len bytes.
*
* This method calls write until exactly len number of bytes has
* been written. A write() call is retried if the underlying
* syscall was interrupted.
*
* @param data Data to write.
* @param len Number of bytes to write.
*/
void writeAll(const uint8_t *data, size_t len);
/**
* Bool to track if the device has been used or not.
*
* We need to keep track of if the device has been used as we are
* unable to checkpoint the device in the event that the device
* has been mounted in the guest system. This is due to the fact
* that we do not, and cannot, track the complete state across
* host and guest.
*/
bool deviceUsed;
};
struct VirtIO9PDiodParams;
/**
* VirtIO 9p proxy that communicates with the diod 9p server using
* pipes.
*/
class VirtIO9PDiod : public VirtIO9PProxy
{
public:
typedef VirtIO9PDiodParams Params;
VirtIO9PDiod(Params *params);
virtual ~VirtIO9PDiod();
void startup();
protected:
/**
* Start diod and setup the communication pipes.
*/
void startDiod();
ssize_t read(uint8_t *data, size_t len);
ssize_t write(const uint8_t *data, size_t len);
/** Kill the diod child process at the end of the simulation */
void terminateDiod();
private:
class DiodDataEvent : public PollEvent
{
public:
DiodDataEvent(VirtIO9PDiod &_parent, int fd, int event)
: PollEvent(fd, event), parent(_parent) {}
virtual ~DiodDataEvent() {};
void process(int revent);
private:
VirtIO9PDiod &parent;
};
/** fd for data pipe going to diod (write end) */
int fd_to_diod;
/** fd for data pipe coming from diod (read end) */
int fd_from_diod;
std::unique_ptr<DiodDataEvent> dataEvent;
/** PID of diod process */
int diod_pid;
};
struct VirtIO9PSocketParams;
/**
* VirtIO 9p proxy that communicates with a 9p server over tcp
* sockets.
*/
class VirtIO9PSocket : public VirtIO9PProxy
{
public:
typedef VirtIO9PSocketParams Params;
VirtIO9PSocket(Params *params);
virtual ~VirtIO9PSocket();
void startup();
protected:
/**
* Try to resolve the server name and connect to the 9p server.
*/
void connectSocket();
/** 9p server disconnect notification */
void socketDisconnect();
ssize_t read(uint8_t *data, size_t len);
ssize_t write(const uint8_t *data, size_t len);
private:
class SocketDataEvent : public PollEvent
{
public:
SocketDataEvent(VirtIO9PSocket &_parent, int fd, int event)
: PollEvent(fd, event), parent(_parent) {}
virtual ~SocketDataEvent() {};
void process(int revent);
private:
VirtIO9PSocket &parent;
};
/** Socket connected to the 9p server */
int fdSocket;
std::unique_ptr<SocketDataEvent> dataEvent;
};
#endif // __DEV_VIRTIO_FS9P_HH__