xref: /openbmc/qemu/include/exec/cpu-defs.h (revision 597f9b2d)
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 2.1 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 #ifndef CONFIG_USER_ONLY
29 #include "exec/hwaddr.h"
30 #endif
31 #include "exec/memattrs.h"
32 #include "hw/core/cpu.h"
33 
34 #include "cpu-param.h"
35 
36 #ifndef TARGET_LONG_BITS
37 # error TARGET_LONG_BITS must be defined in cpu-param.h
38 #endif
39 #ifndef NB_MMU_MODES
40 # error NB_MMU_MODES must be defined in cpu-param.h
41 #endif
42 #ifndef TARGET_PHYS_ADDR_SPACE_BITS
43 # error TARGET_PHYS_ADDR_SPACE_BITS must be defined in cpu-param.h
44 #endif
45 #ifndef TARGET_VIRT_ADDR_SPACE_BITS
46 # error TARGET_VIRT_ADDR_SPACE_BITS must be defined in cpu-param.h
47 #endif
48 #ifndef TARGET_PAGE_BITS
49 # ifdef TARGET_PAGE_BITS_VARY
50 #  ifndef TARGET_PAGE_BITS_MIN
51 #   error TARGET_PAGE_BITS_MIN must be defined in cpu-param.h
52 #  endif
53 # else
54 #  error TARGET_PAGE_BITS must be defined in cpu-param.h
55 # endif
56 #endif
57 
58 #define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
59 
60 /* target_ulong is the type of a virtual address */
61 #if TARGET_LONG_SIZE == 4
62 typedef int32_t target_long;
63 typedef uint32_t target_ulong;
64 #define TARGET_FMT_lx "%08x"
65 #define TARGET_FMT_ld "%d"
66 #define TARGET_FMT_lu "%u"
67 #elif TARGET_LONG_SIZE == 8
68 typedef int64_t target_long;
69 typedef uint64_t target_ulong;
70 #define TARGET_FMT_lx "%016" PRIx64
71 #define TARGET_FMT_ld "%" PRId64
72 #define TARGET_FMT_lu "%" PRIu64
73 #else
74 #error TARGET_LONG_SIZE undefined
75 #endif
76 
77 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
78 
79 /* use a fully associative victim tlb of 8 entries */
80 #define CPU_VTLB_SIZE 8
81 
82 #if HOST_LONG_BITS == 32 && TARGET_LONG_BITS == 32
83 #define CPU_TLB_ENTRY_BITS 4
84 #else
85 #define CPU_TLB_ENTRY_BITS 5
86 #endif
87 
88 #define CPU_TLB_DYN_MIN_BITS 6
89 #define CPU_TLB_DYN_DEFAULT_BITS 8
90 
91 # if HOST_LONG_BITS == 32
92 /* Make sure we do not require a double-word shift for the TLB load */
93 #  define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS)
94 # else /* HOST_LONG_BITS == 64 */
95 /*
96  * Assuming TARGET_PAGE_BITS==12, with 2**22 entries we can cover 2**(22+12) ==
97  * 2**34 == 16G of address space. This is roughly what one would expect a
98  * TLB to cover in a modern (as of 2018) x86_64 CPU. For instance, Intel
99  * Skylake's Level-2 STLB has 16 1G entries.
100  * Also, make sure we do not size the TLB past the guest's address space.
101  */
102 #  ifdef TARGET_PAGE_BITS_VARY
103 #   define CPU_TLB_DYN_MAX_BITS                                  \
104     MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
105 #  else
106 #   define CPU_TLB_DYN_MAX_BITS                                  \
107     MIN_CONST(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
108 #  endif
109 # endif
110 
111 /* Minimalized TLB entry for use by TCG fast path. */
112 typedef struct CPUTLBEntry {
113     /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
114        bit TARGET_PAGE_BITS-1..4  : Nonzero for accesses that should not
115                                     go directly to ram.
116        bit 3                      : indicates that the entry is invalid
117        bit 2..0                   : zero
118     */
119     union {
120         struct {
121             target_ulong addr_read;
122             target_ulong addr_write;
123             target_ulong addr_code;
124             /* Addend to virtual address to get host address.  IO accesses
125                use the corresponding iotlb value.  */
126             uintptr_t addend;
127         };
128         /* padding to get a power of two size */
129         uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
130     };
131 } CPUTLBEntry;
132 
133 QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
134 
135 
136 #endif  /* !CONFIG_USER_ONLY && CONFIG_TCG */
137 
138 #if !defined(CONFIG_USER_ONLY)
139 /*
140  * The full TLB entry, which is not accessed by generated TCG code,
141  * so the layout is not as critical as that of CPUTLBEntry. This is
142  * also why we don't want to combine the two structs.
143  */
144 typedef struct CPUTLBEntryFull {
145     /*
146      * @xlat_section contains:
147      *  - in the lower TARGET_PAGE_BITS, a physical section number
148      *  - with the lower TARGET_PAGE_BITS masked off, an offset which
149      *    must be added to the virtual address to obtain:
150      *     + the ram_addr_t of the target RAM (if the physical section
151      *       number is PHYS_SECTION_NOTDIRTY or PHYS_SECTION_ROM)
152      *     + the offset within the target MemoryRegion (otherwise)
153      */
154     hwaddr xlat_section;
155 
156     /*
157      * @phys_addr contains the physical address in the address space
158      * given by cpu_asidx_from_attrs(cpu, @attrs).
159      */
160     hwaddr phys_addr;
161 
162     /* @attrs contains the memory transaction attributes for the page. */
163     MemTxAttrs attrs;
164 
165     /* @prot contains the complete protections for the page. */
166     uint8_t prot;
167 
168     /* @lg_page_size contains the log2 of the page size. */
169     uint8_t lg_page_size;
170 
171     /*
172      * Allow target-specific additions to this structure.
173      * This may be used to cache items from the guest cpu
174      * page tables for later use by the implementation.
175      */
176 #ifdef TARGET_PAGE_ENTRY_EXTRA
177     TARGET_PAGE_ENTRY_EXTRA
178 #endif
179 } CPUTLBEntryFull;
180 #endif  /* !CONFIG_USER_ONLY */
181 
182 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
183 /*
184  * Data elements that are per MMU mode, minus the bits accessed by
185  * the TCG fast path.
186  */
187 typedef struct CPUTLBDesc {
188     /*
189      * Describe a region covering all of the large pages allocated
190      * into the tlb.  When any page within this region is flushed,
191      * we must flush the entire tlb.  The region is matched if
192      * (addr & large_page_mask) == large_page_addr.
193      */
194     target_ulong large_page_addr;
195     target_ulong large_page_mask;
196     /* host time (in ns) at the beginning of the time window */
197     int64_t window_begin_ns;
198     /* maximum number of entries observed in the window */
199     size_t window_max_entries;
200     size_t n_used_entries;
201     /* The next index to use in the tlb victim table.  */
202     size_t vindex;
203     /* The tlb victim table, in two parts.  */
204     CPUTLBEntry vtable[CPU_VTLB_SIZE];
205     CPUTLBEntryFull vfulltlb[CPU_VTLB_SIZE];
206     CPUTLBEntryFull *fulltlb;
207 } CPUTLBDesc;
208 
209 /*
210  * Data elements that are per MMU mode, accessed by the fast path.
211  * The structure is aligned to aid loading the pair with one insn.
212  */
213 typedef struct CPUTLBDescFast {
214     /* Contains (n_entries - 1) << CPU_TLB_ENTRY_BITS */
215     uintptr_t mask;
216     /* The array of tlb entries itself. */
217     CPUTLBEntry *table;
218 } CPUTLBDescFast QEMU_ALIGNED(2 * sizeof(void *));
219 
220 /*
221  * Data elements that are shared between all MMU modes.
222  */
223 typedef struct CPUTLBCommon {
224     /* Serialize updates to f.table and d.vtable, and others as noted. */
225     QemuSpin lock;
226     /*
227      * Within dirty, for each bit N, modifications have been made to
228      * mmu_idx N since the last time that mmu_idx was flushed.
229      * Protected by tlb_c.lock.
230      */
231     uint16_t dirty;
232     /*
233      * Statistics.  These are not lock protected, but are read and
234      * written atomically.  This allows the monitor to print a snapshot
235      * of the stats without interfering with the cpu.
236      */
237     size_t full_flush_count;
238     size_t part_flush_count;
239     size_t elide_flush_count;
240 } CPUTLBCommon;
241 
242 /*
243  * The entire softmmu tlb, for all MMU modes.
244  * The meaning of each of the MMU modes is defined in the target code.
245  * Since this is placed within CPUNegativeOffsetState, the smallest
246  * negative offsets are at the end of the struct.
247  */
248 
249 typedef struct CPUTLB {
250     CPUTLBCommon c;
251     CPUTLBDesc d[NB_MMU_MODES];
252     CPUTLBDescFast f[NB_MMU_MODES];
253 } CPUTLB;
254 
255 /* This will be used by TCG backends to compute offsets.  */
256 #define TLB_MASK_TABLE_OFS(IDX) \
257     ((int)offsetof(ArchCPU, neg.tlb.f[IDX]) - (int)offsetof(ArchCPU, env))
258 
259 #else
260 
261 typedef struct CPUTLB { } CPUTLB;
262 
263 #endif  /* !CONFIG_USER_ONLY && CONFIG_TCG */
264 
265 /*
266  * This structure must be placed in ArchCPU immediately
267  * before CPUArchState, as a field named "neg".
268  */
269 typedef struct CPUNegativeOffsetState {
270     CPUTLB tlb;
271     IcountDecr icount_decr;
272 } CPUNegativeOffsetState;
273 
274 #endif
275