xref: /qemu/include/exec/cpu-defs.h (revision 513823e7521a09ed7ad1e32e6454bac3b2cbf52d)
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 COMPILING_PER_TARGET
23 #error cpu.h included from common code
24 #endif
25 
26 #include "cpu-param.h"
27 
28 #ifndef TARGET_LONG_BITS
29 # error TARGET_LONG_BITS must be defined in cpu-param.h
30 #endif
31 #ifndef TARGET_PHYS_ADDR_SPACE_BITS
32 # error TARGET_PHYS_ADDR_SPACE_BITS must be defined in cpu-param.h
33 #endif
34 #ifndef TARGET_VIRT_ADDR_SPACE_BITS
35 # error TARGET_VIRT_ADDR_SPACE_BITS must be defined in cpu-param.h
36 #endif
37 #ifndef TARGET_PAGE_BITS
38 # ifdef TARGET_PAGE_BITS_VARY
39 #  ifndef TARGET_PAGE_BITS_MIN
40 #   error TARGET_PAGE_BITS_MIN must be defined in cpu-param.h
41 #  endif
42 # else
43 #  error TARGET_PAGE_BITS must be defined in cpu-param.h
44 # endif
45 #endif
46 
47 #include "exec/target_long.h"
48 
49 #if defined(CONFIG_SOFTMMU) && defined(CONFIG_TCG)
50 #define CPU_TLB_DYN_MIN_BITS 6
51 #define CPU_TLB_DYN_DEFAULT_BITS 8
52 
53 # if HOST_LONG_BITS == 32
54 /* Make sure we do not require a double-word shift for the TLB load */
55 #  define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS)
56 # else /* HOST_LONG_BITS == 64 */
57 /*
58  * Assuming TARGET_PAGE_BITS==12, with 2**22 entries we can cover 2**(22+12) ==
59  * 2**34 == 16G of address space. This is roughly what one would expect a
60  * TLB to cover in a modern (as of 2018) x86_64 CPU. For instance, Intel
61  * Skylake's Level-2 STLB has 16 1G entries.
62  * Also, make sure we do not size the TLB past the guest's address space.
63  */
64 #  ifdef TARGET_PAGE_BITS_VARY
65 #   define CPU_TLB_DYN_MAX_BITS                                  \
66     MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
67 #  else
68 #   define CPU_TLB_DYN_MAX_BITS                                  \
69     MIN_CONST(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
70 #  endif
71 # endif
72 
73 #endif /* CONFIG_SOFTMMU && CONFIG_TCG */
74 
75 #endif
76