qemu/include/exec/cpu-defs.h
Richard Henderson 0b3c75ad1a accel/tcg: Introduce tlb_read_idx
Instead of playing with offsetof in various places, use
MMUAccessType to index an array.  This is easily defined
instead of the previous dummy padding array in the union.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-05-11 09:53:41 +01:00

264 lines
8.1 KiB
C

/*
* common defines for all CPUs
*
* Copyright (c) 2003 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef CPU_DEFS_H
#define CPU_DEFS_H
#ifndef NEED_CPU_H
#error cpu.h included from common code
#endif
#include "qemu/host-utils.h"
#include "qemu/thread.h"
#ifndef CONFIG_USER_ONLY
#include "exec/hwaddr.h"
#endif
#include "exec/memattrs.h"
#include "hw/core/cpu.h"
#include "cpu-param.h"
#ifndef TARGET_LONG_BITS
# error TARGET_LONG_BITS must be defined in cpu-param.h
#endif
#ifndef TARGET_PHYS_ADDR_SPACE_BITS
# error TARGET_PHYS_ADDR_SPACE_BITS must be defined in cpu-param.h
#endif
#ifndef TARGET_VIRT_ADDR_SPACE_BITS
# error TARGET_VIRT_ADDR_SPACE_BITS must be defined in cpu-param.h
#endif
#ifndef TARGET_PAGE_BITS
# ifdef TARGET_PAGE_BITS_VARY
# ifndef TARGET_PAGE_BITS_MIN
# error TARGET_PAGE_BITS_MIN must be defined in cpu-param.h
# endif
# else
# error TARGET_PAGE_BITS must be defined in cpu-param.h
# endif
#endif
#include "exec/target_long.h"
/*
* Fix the number of mmu modes to 16, which is also the maximum
* supported by the softmmu tlb api.
*/
#define NB_MMU_MODES 16
#if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
/* use a fully associative victim tlb of 8 entries */
#define CPU_VTLB_SIZE 8
#if HOST_LONG_BITS == 32 && TARGET_LONG_BITS == 32
#define CPU_TLB_ENTRY_BITS 4
#else
#define CPU_TLB_ENTRY_BITS 5
#endif
#define CPU_TLB_DYN_MIN_BITS 6
#define CPU_TLB_DYN_DEFAULT_BITS 8
# if HOST_LONG_BITS == 32
/* Make sure we do not require a double-word shift for the TLB load */
# define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS)
# else /* HOST_LONG_BITS == 64 */
/*
* Assuming TARGET_PAGE_BITS==12, with 2**22 entries we can cover 2**(22+12) ==
* 2**34 == 16G of address space. This is roughly what one would expect a
* TLB to cover in a modern (as of 2018) x86_64 CPU. For instance, Intel
* Skylake's Level-2 STLB has 16 1G entries.
* Also, make sure we do not size the TLB past the guest's address space.
*/
# ifdef TARGET_PAGE_BITS_VARY
# define CPU_TLB_DYN_MAX_BITS \
MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
# else
# define CPU_TLB_DYN_MAX_BITS \
MIN_CONST(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
# endif
# endif
/* Minimalized TLB entry for use by TCG fast path. */
typedef struct CPUTLBEntry {
/* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
bit TARGET_PAGE_BITS-1..4 : Nonzero for accesses that should not
go directly to ram.
bit 3 : indicates that the entry is invalid
bit 2..0 : zero
*/
union {
struct {
target_ulong addr_read;
target_ulong addr_write;
target_ulong addr_code;
/* Addend to virtual address to get host address. IO accesses
use the corresponding iotlb value. */
uintptr_t addend;
};
/*
* Padding to get a power of two size, as well as index
* access to addr_{read,write,code}.
*/
target_ulong addr_idx[(1 << CPU_TLB_ENTRY_BITS) / TARGET_LONG_SIZE];
};
} CPUTLBEntry;
QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
#endif /* !CONFIG_USER_ONLY && CONFIG_TCG */
#if !defined(CONFIG_USER_ONLY)
/*
* The full TLB entry, which is not accessed by generated TCG code,
* so the layout is not as critical as that of CPUTLBEntry. This is
* also why we don't want to combine the two structs.
*/
typedef struct CPUTLBEntryFull {
/*
* @xlat_section contains:
* - in the lower TARGET_PAGE_BITS, a physical section number
* - with the lower TARGET_PAGE_BITS masked off, an offset which
* must be added to the virtual address to obtain:
* + the ram_addr_t of the target RAM (if the physical section
* number is PHYS_SECTION_NOTDIRTY or PHYS_SECTION_ROM)
* + the offset within the target MemoryRegion (otherwise)
*/
hwaddr xlat_section;
/*
* @phys_addr contains the physical address in the address space
* given by cpu_asidx_from_attrs(cpu, @attrs).
*/
hwaddr phys_addr;
/* @attrs contains the memory transaction attributes for the page. */
MemTxAttrs attrs;
/* @prot contains the complete protections for the page. */
uint8_t prot;
/* @lg_page_size contains the log2 of the page size. */
uint8_t lg_page_size;
/*
* Allow target-specific additions to this structure.
* This may be used to cache items from the guest cpu
* page tables for later use by the implementation.
*/
#ifdef TARGET_PAGE_ENTRY_EXTRA
TARGET_PAGE_ENTRY_EXTRA
#endif
} CPUTLBEntryFull;
#endif /* !CONFIG_USER_ONLY */
#if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
/*
* Data elements that are per MMU mode, minus the bits accessed by
* the TCG fast path.
*/
typedef struct CPUTLBDesc {
/*
* Describe a region covering all of the large pages allocated
* into the tlb. When any page within this region is flushed,
* we must flush the entire tlb. The region is matched if
* (addr & large_page_mask) == large_page_addr.
*/
target_ulong large_page_addr;
target_ulong large_page_mask;
/* host time (in ns) at the beginning of the time window */
int64_t window_begin_ns;
/* maximum number of entries observed in the window */
size_t window_max_entries;
size_t n_used_entries;
/* The next index to use in the tlb victim table. */
size_t vindex;
/* The tlb victim table, in two parts. */
CPUTLBEntry vtable[CPU_VTLB_SIZE];
CPUTLBEntryFull vfulltlb[CPU_VTLB_SIZE];
CPUTLBEntryFull *fulltlb;
} CPUTLBDesc;
/*
* Data elements that are per MMU mode, accessed by the fast path.
* The structure is aligned to aid loading the pair with one insn.
*/
typedef struct CPUTLBDescFast {
/* Contains (n_entries - 1) << CPU_TLB_ENTRY_BITS */
uintptr_t mask;
/* The array of tlb entries itself. */
CPUTLBEntry *table;
} CPUTLBDescFast QEMU_ALIGNED(2 * sizeof(void *));
/*
* Data elements that are shared between all MMU modes.
*/
typedef struct CPUTLBCommon {
/* Serialize updates to f.table and d.vtable, and others as noted. */
QemuSpin lock;
/*
* Within dirty, for each bit N, modifications have been made to
* mmu_idx N since the last time that mmu_idx was flushed.
* Protected by tlb_c.lock.
*/
uint16_t dirty;
/*
* Statistics. These are not lock protected, but are read and
* written atomically. This allows the monitor to print a snapshot
* of the stats without interfering with the cpu.
*/
size_t full_flush_count;
size_t part_flush_count;
size_t elide_flush_count;
} CPUTLBCommon;
/*
* The entire softmmu tlb, for all MMU modes.
* The meaning of each of the MMU modes is defined in the target code.
* Since this is placed within CPUNegativeOffsetState, the smallest
* negative offsets are at the end of the struct.
*/
typedef struct CPUTLB {
CPUTLBCommon c;
CPUTLBDesc d[NB_MMU_MODES];
CPUTLBDescFast f[NB_MMU_MODES];
} CPUTLB;
/* This will be used by TCG backends to compute offsets. */
#define TLB_MASK_TABLE_OFS(IDX) \
((int)offsetof(ArchCPU, neg.tlb.f[IDX]) - (int)offsetof(ArchCPU, env))
#else
typedef struct CPUTLB { } CPUTLB;
#endif /* !CONFIG_USER_ONLY && CONFIG_TCG */
/*
* This structure must be placed in ArchCPU immediately
* before CPUArchState, as a field named "neg".
*/
typedef struct CPUNegativeOffsetState {
CPUTLB tlb;
IcountDecr icount_decr;
} CPUNegativeOffsetState;
#endif