include/exec/cpu-defs.h

   1 /*
   2  * common defines for all CPUs
   3  *
   4  * Copyright (c) 2003 Fabrice Bellard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #ifndef CPU_DEFS_H
  20 #define CPU_DEFS_H
  21
  22 #ifndef NEED_CPU_H
  23 #error cpu.h included from common code
  24 #endif
  25
  26 #include "qemu/host-utils.h"
  27 #include "qemu/thread.h"
  28 #ifdef CONFIG_TCG
  29 #include "tcg-target.h"
  30 #endif
  31 #ifndef CONFIG_USER_ONLY
  32 #include "exec/hwaddr.h"
  33 #endif
  34 #include "exec/memattrs.h"
  35 #include "hw/core/cpu.h"
  36
  37 #include "cpu-param.h"
  38
  39 #ifndef TARGET_LONG_BITS
  40 # error TARGET_LONG_BITS must be defined in cpu-param.h
  41 #endif
  42 #ifndef NB_MMU_MODES
  43 # error NB_MMU_MODES must be defined in cpu-param.h
  44 #endif
  45 #ifndef TARGET_PHYS_ADDR_SPACE_BITS
  46 # error TARGET_PHYS_ADDR_SPACE_BITS must be defined in cpu-param.h
  47 #endif
  48 #ifndef TARGET_VIRT_ADDR_SPACE_BITS
  49 # error TARGET_VIRT_ADDR_SPACE_BITS must be defined in cpu-param.h
  50 #endif
  51 #ifndef TARGET_PAGE_BITS
  52 # ifdef TARGET_PAGE_BITS_VARY
  53 #  ifndef TARGET_PAGE_BITS_MIN
  54 #   error TARGET_PAGE_BITS_MIN must be defined in cpu-param.h
  55 #  endif
  56 # else
  57 #  error TARGET_PAGE_BITS must be defined in cpu-param.h
  58 # endif
  59 #endif
  60
  61 #define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
  62
  63 /* target_ulong is the type of a virtual address */
  64 #if TARGET_LONG_SIZE == 4
  65 typedef int32_t target_long;
  66 typedef uint32_t target_ulong;
  67 #define TARGET_FMT_lx "%08x"
  68 #define TARGET_FMT_ld "%d"
  69 #define TARGET_FMT_lu "%u"
  70 #elif TARGET_LONG_SIZE == 8
  71 typedef int64_t target_long;
  72 typedef uint64_t target_ulong;
  73 #define TARGET_FMT_lx "%016" PRIx64
  74 #define TARGET_FMT_ld "%" PRId64
  75 #define TARGET_FMT_lu "%" PRIu64
  76 #else
  77 #error TARGET_LONG_SIZE undefined
  78 #endif
  79
  80 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
  81
  82 /* use a fully associative victim tlb of 8 entries */
  83 #define CPU_VTLB_SIZE 8
  84
  85 #if HOST_LONG_BITS == 32 && TARGET_LONG_BITS == 32
  86 #define CPU_TLB_ENTRY_BITS 4
  87 #else
  88 #define CPU_TLB_ENTRY_BITS 5
  89 #endif
  90
  91 #define CPU_TLB_DYN_MIN_BITS 6
  92 #define CPU_TLB_DYN_DEFAULT_BITS 8
  93
  94 # if HOST_LONG_BITS == 32
  95 /* Make sure we do not require a double-word shift for the TLB load */
  96 #  define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS)
  97 # else /* HOST_LONG_BITS == 64 */
  98 /*
  99  * Assuming TARGET_PAGE_BITS==12, with 2**22 entries we can cover 2**(22+12) ==
 100  * 2**34 == 16G of address space. This is roughly what one would expect a
 101  * TLB to cover in a modern (as of 2018) x86_64 CPU. For instance, Intel
 102  * Skylake's Level-2 STLB has 16 1G entries.
 103  * Also, make sure we do not size the TLB past the guest's address space.
 104  */
 105 #  ifdef TARGET_PAGE_BITS_VARY
 106 #   define CPU_TLB_DYN_MAX_BITS                                  \
 107     MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
 108 #  else
 109 #   define CPU_TLB_DYN_MAX_BITS                                  \
 110     MIN_CONST(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
 111 #  endif
 112 # endif
 113
 114 typedef struct CPUTLBEntry {
 115     /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
 116        bit TARGET_PAGE_BITS-1..4  : Nonzero for accesses that should not
 117                                     go directly to ram.
 118        bit 3                      : indicates that the entry is invalid
 119        bit 2..0                   : zero
 120     */
 121     union {
 122         struct {
 123             target_ulong addr_read;
 124             target_ulong addr_write;
 125             target_ulong addr_code;
 126             /* Addend to virtual address to get host address.  IO accesses
 127                use the corresponding iotlb value.  */
 128             uintptr_t addend;
 129         };
 130         /* padding to get a power of two size */
 131         uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
 132     };
 133 } CPUTLBEntry;
 134
 135 QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
 136
 137 /* The IOTLB is not accessed directly inline by generated TCG code,
 138  * so the CPUIOTLBEntry layout is not as critical as that of the
 139  * CPUTLBEntry. (This is also why we don't want to combine the two
 140  * structs into one.)
 141  */
 142 typedef struct CPUIOTLBEntry {
 143     /*
 144      * @addr contains:
 145      *  - in the lower TARGET_PAGE_BITS, a physical section number
 146      *  - with the lower TARGET_PAGE_BITS masked off, an offset which
 147      *    must be added to the virtual address to obtain:
 148      *     + the ram_addr_t of the target RAM (if the physical section
 149      *       number is PHYS_SECTION_NOTDIRTY or PHYS_SECTION_ROM)
 150      *     + the offset within the target MemoryRegion (otherwise)
 151      */
 152     hwaddr addr;
 153     MemTxAttrs attrs;
 154 } CPUIOTLBEntry;
 155
 156 /*
 157  * Data elements that are per MMU mode, minus the bits accessed by
 158  * the TCG fast path.
 159  */
 160 typedef struct CPUTLBDesc {
 161     /*
 162      * Describe a region covering all of the large pages allocated
 163      * into the tlb.  When any page within this region is flushed,
 164      * we must flush the entire tlb.  The region is matched if
 165      * (addr & large_page_mask) == large_page_addr.
 166      */
 167     target_ulong large_page_addr;
 168     target_ulong large_page_mask;
 169     /* host time (in ns) at the beginning of the time window */
 170     int64_t window_begin_ns;
 171     /* maximum number of entries observed in the window */
 172     size_t window_max_entries;
 173     size_t n_used_entries;
 174     /* The next index to use in the tlb victim table.  */
 175     size_t vindex;
 176     /* The tlb victim table, in two parts.  */
 177     CPUTLBEntry vtable[CPU_VTLB_SIZE];
 178     CPUIOTLBEntry viotlb[CPU_VTLB_SIZE];
 179     /* The iotlb.  */
 180     CPUIOTLBEntry *iotlb;
 181 } CPUTLBDesc;
 182
 183 /*
 184  * Data elements that are per MMU mode, accessed by the fast path.
 185  * The structure is aligned to aid loading the pair with one insn.
 186  */
 187 typedef struct CPUTLBDescFast {
 188     /* Contains (n_entries - 1) << CPU_TLB_ENTRY_BITS */
 189     uintptr_t mask;
 190     /* The array of tlb entries itself. */
 191     CPUTLBEntry *table;
 192 } CPUTLBDescFast QEMU_ALIGNED(2 * sizeof(void *));
 193
 194 /*
 195  * Data elements that are shared between all MMU modes.
 196  */
 197 typedef struct CPUTLBCommon {
 198     /* Serialize updates to f.table and d.vtable, and others as noted. */
 199     QemuSpin lock;
 200     /*
 201      * Within dirty, for each bit N, modifications have been made to
 202      * mmu_idx N since the last time that mmu_idx was flushed.
 203      * Protected by tlb_c.lock.
 204      */
 205     uint16_t dirty;
 206     /*
 207      * Statistics.  These are not lock protected, but are read and
 208      * written atomically.  This allows the monitor to print a snapshot
 209      * of the stats without interfering with the cpu.
 210      */
 211     size_t full_flush_count;
 212     size_t part_flush_count;
 213     size_t elide_flush_count;
 214 } CPUTLBCommon;
 215
 216 /*
 217  * The entire softmmu tlb, for all MMU modes.
 218  * The meaning of each of the MMU modes is defined in the target code.
 219  * Since this is placed within CPUNegativeOffsetState, the smallest
 220  * negative offsets are at the end of the struct.
 221  */
 222
 223 typedef struct CPUTLB {
 224     CPUTLBCommon c;
 225     CPUTLBDesc d[NB_MMU_MODES];
 226     CPUTLBDescFast f[NB_MMU_MODES];
 227 } CPUTLB;
 228
 229 /* This will be used by TCG backends to compute offsets.  */
 230 #define TLB_MASK_TABLE_OFS(IDX) \
 231     ((int)offsetof(ArchCPU, neg.tlb.f[IDX]) - (int)offsetof(ArchCPU, env))
 232
 233 #else
 234
 235 typedef struct CPUTLB { } CPUTLB;
 236
 237 #endif  /* !CONFIG_USER_ONLY && CONFIG_TCG */
 238
 239 /*
 240  * This structure must be placed in ArchCPU immediately
 241  * before CPUArchState, as a field named "neg".
 242  */
 243 typedef struct CPUNegativeOffsetState {
 244     CPUTLB tlb;
 245     IcountDecr icount_decr;
 246 } CPUNegativeOffsetState;
 247
 248 #endif