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/*
* Copyright (c) 2012 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.
*/
#ifndef __MEM_PHYSICAL_HH__
#define __MEM_PHYSICAL_HH__
#include <cstdint>
#include <string>
#include <vector>
#include "base/addr_range.hh"
#include "base/addr_range_map.hh"
#include "mem/packet.hh"
#include "sim/serialize.hh"
namespace gem5
{
namespace memory
{
/**
* Forward declaration to avoid header dependencies.
*/
class AbstractMemory;
/**
* A single entry for the backing store.
*/
class BackingStoreEntry
{
public:
/**
* Create a backing store entry. Don't worry about managing the memory
* pointers, because PhysicalMemory is responsible for that.
*/
BackingStoreEntry(AddrRange range, uint8_t* pmem,
bool conf_table_reported, bool in_addr_map, bool kvm_map,
int shm_fd=-1, off_t shm_offset=0)
: range(range), pmem(pmem), confTableReported(conf_table_reported),
inAddrMap(in_addr_map), kvmMap(kvm_map), shmFd(shm_fd),
shmOffset(shm_offset)
{}
/**
* The address range covered in the guest.
*/
AddrRange range;
/**
* Pointer to the host memory this range maps to. This memory is the same
* size as the range field.
*/
uint8_t* pmem;
/**
* Whether this memory should be reported to the configuration table
*/
bool confTableReported;
/**
* Whether this memory should appear in the global address map
*/
bool inAddrMap;
/**
* Whether KVM should map this memory into the guest address space during
* acceleration.
*/
bool kvmMap;
/**
* If this backing store is based on a shared memory, this is the fd to
* the shared memory. Otherwise, it should be -1.
*/
int shmFd;
/**
* If this backing store is based on a shared memory, this is the offset
* of this backing store in the share memory. Otherwise, the value is 0.
*/
off_t shmOffset;
};
/**
* The physical memory encapsulates all memories in the system and
* provides basic functionality for accessing those memories without
* going through the memory system and interconnect.
*
* The physical memory is also responsible for providing the host
* system backingstore used by the memories in the simulated guest
* system. When the system is created, the physical memory allocates
* the backing store based on the address ranges that are populated in
* the system, and does so independent of how those map to actual
* memory controllers. Thus, the physical memory completely abstracts
* the mapping of the backing store of the host system and the address
* mapping in the guest system. This enables us to arbitrarily change
* the number of memory controllers, and their address mapping, as
* long as the ranges stay the same.
*/
class PhysicalMemory : public Serializable
{
private:
// Name for debugging
std::string _name;
// Global address map
AddrRangeMap<AbstractMemory*, 1> addrMap;
// All address-mapped memories
std::vector<AbstractMemory*> memories;
// The total memory size
uint64_t size;
// Let the user choose if we reserve swap space when calling mmap
const bool mmapUsingNoReserve;
const std::string sharedBackstore;
uint64_t sharedBackstoreSize;
long pageSize;
// The physical memory used to provide the memory in the simulated
// system
std::vector<BackingStoreEntry> backingStore;
// Prevent copying
PhysicalMemory(const PhysicalMemory&);
// Prevent assignment
PhysicalMemory& operator=(const PhysicalMemory&);
/**
* Create the memory region providing the backing store for a
* given address range that corresponds to a set of memories in
* the simulated system.
*
* @param range The address range covered
* @param memories The memories this range maps to
* @param kvm_map Should KVM map this memory for the guest
*/
void createBackingStore(AddrRange range,
const std::vector<AbstractMemory*>& _memories,
bool conf_table_reported,
bool in_addr_map, bool kvm_map);
public:
/**
* Create a physical memory object, wrapping a number of memories.
*/
PhysicalMemory(const std::string& _name,
const std::vector<AbstractMemory*>& _memories,
bool mmap_using_noreserve,
const std::string& shared_backstore,
bool auto_unlink_shared_backstore);
/**
* Unmap all the backing store we have used.
*/
~PhysicalMemory();
/**
* Return the name for debugging and for creation of sections for
* checkpointing.
*/
const std::string name() const { return _name; }
/**
* Check if a physical address is within a range of a memory that
* is part of the global address map.
*
* @param addr A physical address
* @return Whether the address corresponds to a memory
*/
bool isMemAddr(Addr addr) const;
/**
* Get the memory ranges for all memories that are to be reported
* to the configuration table. The ranges are merged before they
* are returned such that any interleaved ranges appear as a
* single range.
*
* @return All configuration table memory ranges
*/
AddrRangeList getConfAddrRanges() const;
/**
* Get the total physical memory size.
*
* @return The sum of all memory sizes
*/
uint64_t totalSize() const { return size; }
/**
* Get the pointers to the backing store for external host
* access. Note that memory in the guest should be accessed using
* access() or functionalAccess(). This interface is primarily
* intended for CPU models using hardware virtualization. Note
* that memories that are null are not present, and that the
* backing store may also contain memories that are not part of
* the OS-visible global address map and thus are allowed to
* overlap.
*
* @return Pointers to the memory backing store
*/
std::vector<BackingStoreEntry> getBackingStore() const
{ return backingStore; }
/**
* Perform an untimed memory access and update all the state
* (e.g. locked addresses) and statistics accordingly. The packet
* is turned into a response if required.
*
* @param pkt Packet performing the access
*/
void access(PacketPtr pkt);
/**
* Perform an untimed memory read or write without changing
* anything but the memory itself. No stats are affected by this
* access. In addition to normal accesses this also facilitates
* print requests.
*
* @param pkt Packet performing the access
*/
void functionalAccess(PacketPtr pkt);
/**
* Serialize all the memories in the system. This is independent
* of the logical memory layout, and the serialization only sees
* the contigous backing store, independent of how this maps to
* logical memories in the guest system.
*
* @param os stream to serialize to
*/
void serialize(CheckpointOut &cp) const override;
/**
* Serialize a specific store.
*
* @param store_id Unique identifier of this backing store
* @param range The address range of this backing store
* @param pmem The host pointer to this backing store
*/
void serializeStore(CheckpointOut &cp, unsigned int store_id,
AddrRange range, uint8_t* pmem) const;
/**
* Unserialize the memories in the system. As with the
* serialization, this action is independent of how the address
* ranges are mapped to logical memories in the guest system.
*/
void unserialize(CheckpointIn &cp) override;
/**
* Unserialize a specific backing store, identified by a section.
*/
void unserializeStore(CheckpointIn &cp);
};
} // namespace memory
} // namespace gem5
#endif //__MEM_PHYSICAL_HH__