xemu/include/exec/tb-hash.h
Lluís Vilanova 61a67f71dd exec: [tcg] Use different TBs according to the vCPU's dynamic tracing state
Every vCPU now uses a separate set of TBs for each set of dynamic
tracing event state values. Each set of TBs can be used by any number of
vCPUs to maximize TB reuse when vCPUs have the same tracing state.

This feature is later used by tracetool to optimize tracing of guest
code events.

The maximum number of TB sets is defined as 2^E, where E is the number
of events that have the 'vcpu' property (their state is stored in
CPUState->trace_dstate).

For this to work, a change on the dynamic tracing state of a vCPU will
force it to flush its virtual TB cache (which is only indexed by
address), and fall back to the physical TB cache (which now contains the
vCPU's dynamic tracing state as part of the hashing function).

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-id: 149915775266.6295.10060144081246467690.stgit@frigg.lan
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-07-17 13:11:05 +01:00

68 lines
2.2 KiB
C

/*
* internal execution defines for qemu
*
* 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 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 EXEC_TB_HASH_H
#define EXEC_TB_HASH_H
#include "exec/tb-hash-xx.h"
#ifdef CONFIG_SOFTMMU
/* Only the bottom TB_JMP_PAGE_BITS of the jump cache hash bits vary for
addresses on the same page. The top bits are the same. This allows
TLB invalidation to quickly clear a subset of the hash table. */
#define TB_JMP_PAGE_BITS (TB_JMP_CACHE_BITS / 2)
#define TB_JMP_PAGE_SIZE (1 << TB_JMP_PAGE_BITS)
#define TB_JMP_ADDR_MASK (TB_JMP_PAGE_SIZE - 1)
#define TB_JMP_PAGE_MASK (TB_JMP_CACHE_SIZE - TB_JMP_PAGE_SIZE)
static inline unsigned int tb_jmp_cache_hash_page(target_ulong pc)
{
target_ulong tmp;
tmp = pc ^ (pc >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS));
return (tmp >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS)) & TB_JMP_PAGE_MASK;
}
static inline unsigned int tb_jmp_cache_hash_func(target_ulong pc)
{
target_ulong tmp;
tmp = pc ^ (pc >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS));
return (((tmp >> (TARGET_PAGE_BITS - TB_JMP_PAGE_BITS)) & TB_JMP_PAGE_MASK)
| (tmp & TB_JMP_ADDR_MASK));
}
#else
/* In user-mode we can get better hashing because we do not have a TLB */
static inline unsigned int tb_jmp_cache_hash_func(target_ulong pc)
{
return (pc ^ (pc >> TB_JMP_CACHE_BITS)) & (TB_JMP_CACHE_SIZE - 1);
}
#endif /* CONFIG_SOFTMMU */
static inline
uint32_t tb_hash_func(tb_page_addr_t phys_pc, target_ulong pc, uint32_t flags,
uint32_t trace_vcpu_dstate)
{
return tb_hash_func6(phys_pc, pc, flags, trace_vcpu_dstate);
}
#endif