src/mem/physical.hh

   1 /*
   2  * Copyright (c) 2012 ARM Limited
   3  * All rights reserved
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #ifndef __MEM_PHYSICAL_HH__
  39 #define __MEM_PHYSICAL_HH__
  40
  41 #include "base/addr_range_map.hh"
  42 #include "mem/packet.hh"
  43
  44 /**
  45  * Forward declaration to avoid header dependencies.
  46  */
  47 class AbstractMemory;
  48
  49 /**
  50  * A single entry for the backing store.
  51  */
  52 class BackingStoreEntry
  53 {
  54   public:
  55
  56     /**
  57      * Create a backing store entry. Don't worry about managing the memory
  58      * pointers, because PhysicalMemory is responsible for that.
  59      */
  60     BackingStoreEntry(AddrRange range, uint8_t* pmem,
  61                       bool conf_table_reported, bool in_addr_map, bool kvm_map)
  62         : range(range), pmem(pmem), confTableReported(conf_table_reported),
  63           inAddrMap(in_addr_map), kvmMap(kvm_map)
  64         {}
  65
  66     /**
  67      * The address range covered in the guest.
  68      */
  69      AddrRange range;
  70
  71     /**
  72      * Pointer to the host memory this range maps to. This memory is the same
  73      * size as the range field.
  74      */
  75      uint8_t* pmem;
  76
  77      /**
  78       * Whether this memory should be reported to the configuration table
  79       */
  80      bool confTableReported;
  81
  82      /**
  83       * Whether this memory should appear in the global address map
  84       */
  85      bool inAddrMap;
  86
  87      /**
  88       * Whether KVM should map this memory into the guest address space during
  89       * acceleration.
  90       */
  91      bool kvmMap;
  92 };
  93
  94 /**
  95  * The physical memory encapsulates all memories in the system and
  96  * provides basic functionality for accessing those memories without
  97  * going through the memory system and interconnect.
  98  *
  99  * The physical memory is also responsible for providing the host
 100  * system backingstore used by the memories in the simulated guest
 101  * system. When the system is created, the physical memory allocates
 102  * the backing store based on the address ranges that are populated in
 103  * the system, and does so independent of how those map to actual
 104  * memory controllers. Thus, the physical memory completely abstracts
 105  * the mapping of the backing store of the host system and the address
 106  * mapping in the guest system. This enables us to arbitrarily change
 107  * the number of memory controllers, and their address mapping, as
 108  * long as the ranges stay the same.
 109  */
 110 class PhysicalMemory : public Serializable
 111 {
 112
 113   private:
 114
 115     // Name for debugging
 116     std::string _name;
 117
 118     // Global address map
 119     AddrRangeMap<AbstractMemory*, 1> addrMap;
 120
 121     // All address-mapped memories
 122     std::vector<AbstractMemory*> memories;
 123
 124     // The total memory size
 125     uint64_t size;
 126
 127     // Let the user choose if we reserve swap space when calling mmap
 128     const bool mmapUsingNoReserve;
 129
 130     // The physical memory used to provide the memory in the simulated
 131     // system
 132     std::vector<BackingStoreEntry> backingStore;
 133
 134     // Prevent copying
 135     PhysicalMemory(const PhysicalMemory&);
 136
 137     // Prevent assignment
 138     PhysicalMemory& operator=(const PhysicalMemory&);
 139
 140     /**
 141      * Create the memory region providing the backing store for a
 142      * given address range that corresponds to a set of memories in
 143      * the simulated system.
 144      *
 145      * @param range The address range covered
 146      * @param memories The memories this range maps to
 147      * @param kvm_map Should KVM map this memory for the guest
 148      */
 149     void createBackingStore(AddrRange range,
 150                             const std::vector<AbstractMemory*>& _memories,
 151                             bool conf_table_reported,
 152                             bool in_addr_map, bool kvm_map);
 153
 154   public:
 155
 156     /**
 157      * Create a physical memory object, wrapping a number of memories.
 158      */
 159     PhysicalMemory(const std::string& _name,
 160                    const std::vector<AbstractMemory*>& _memories,
 161                    bool mmap_using_noreserve);
 162
 163     /**
 164      * Unmap all the backing store we have used.
 165      */
 166     ~PhysicalMemory();
 167
 168     /**
 169      * Return the name for debugging and for creation of sections for
 170      * checkpointing.
 171      */
 172     const std::string name() const { return _name; }
 173
 174     /**
 175      * Check if a physical address is within a range of a memory that
 176      * is part of the global address map.
 177      *
 178      * @param addr A physical address
 179      * @return Whether the address corresponds to a memory
 180      */
 181     bool isMemAddr(Addr addr) const;
 182
 183     /**
 184      * Get the memory ranges for all memories that are to be reported
 185      * to the configuration table. The ranges are merged before they
 186      * are returned such that any interleaved ranges appear as a
 187      * single range.
 188      *
 189      * @return All configuration table memory ranges
 190      */
 191     AddrRangeList getConfAddrRanges() const;
 192
 193     /**
 194      * Get the total physical memory size.
 195      *
 196      * @return The sum of all memory sizes
 197      */
 198     uint64_t totalSize() const { return size; }
 199
 200      /**
 201      * Get the pointers to the backing store for external host
 202      * access. Note that memory in the guest should be accessed using
 203      * access() or functionalAccess(). This interface is primarily
 204      * intended for CPU models using hardware virtualization. Note
 205      * that memories that are null are not present, and that the
 206      * backing store may also contain memories that are not part of
 207      * the OS-visible global address map and thus are allowed to
 208      * overlap.
 209      *
 210      * @return Pointers to the memory backing store
 211      */
 212     std::vector<BackingStoreEntry> getBackingStore() const
 213     { return backingStore; }
 214
 215     /**
 216      * Perform an untimed memory access and update all the state
 217      * (e.g. locked addresses) and statistics accordingly. The packet
 218      * is turned into a response if required.
 219      *
 220      * @param pkt Packet performing the access
 221      */
 222     void access(PacketPtr pkt);
 223
 224     /**
 225      * Perform an untimed memory read or write without changing
 226      * anything but the memory itself. No stats are affected by this
 227      * access. In addition to normal accesses this also facilitates
 228      * print requests.
 229      *
 230      * @param pkt Packet performing the access
 231      */
 232     void functionalAccess(PacketPtr pkt);
 233
 234     /**
 235      * Serialize all the memories in the system. This is independent
 236      * of the logical memory layout, and the serialization only sees
 237      * the contigous backing store, independent of how this maps to
 238      * logical memories in the guest system.
 239      *
 240      * @param os stream to serialize to
 241      */
 242     void serialize(CheckpointOut &cp) const override;
 243
 244     /**
 245      * Serialize a specific store.
 246      *
 247      * @param store_id Unique identifier of this backing store
 248      * @param range The address range of this backing store
 249      * @param pmem The host pointer to this backing store
 250      */
 251     void serializeStore(CheckpointOut &cp, unsigned int store_id,
 252                         AddrRange range, uint8_t* pmem) const;
 253
 254     /**
 255      * Unserialize the memories in the system. As with the
 256      * serialization, this action is independent of how the address
 257      * ranges are mapped to logical memories in the guest system.
 258      */
 259     void unserialize(CheckpointIn &cp) override;
 260
 261     /**
 262      * Unserialize a specific backing store, identified by a section.
 263      */
 264     void unserializeStore(CheckpointIn &cp);
 265
 266 };
 267
 268 #endif //__MEM_PHYSICAL_HH__