unicorn/qemu/tcg-runtime.c
Emilio G. Cota 210d13ec49
tcg: consolidate TB lookups in tb_lookup__cpu_state
This avoids duplicating code. cpu_exec_step will also use the
new common function once we integrate parallel_cpus into tb->cflags.

Note that in this commit we also fix a race, described by Richard Henderson
during review. Think of this scenario with threads A and B:

(A) Lookup succeeds for TB in hash without tb_lock
(B) Sets the TB's tb->invalid flag
(B) Removes the TB from tb_htable
(B) Clears all CPU's tb_jmp_cache
(A) Store TB into local tb_jmp_cache

Given that order of events, (A) will keep executing that invalid TB until
another flush of its tb_jmp_cache happens, which in theory might never happen.
We can fix this by checking the tb->invalid flag every time we look up a TB
from tb_jmp_cache, so that in the above scenario, next time we try to find
that TB in tb_jmp_cache, we won't, and will therefore be forced to look it
up in tb_htable.

Performance-wise, I measured a small improvement when booting debian-arm.
Note that inlining pays off:

Performance counter stats for 'taskset -c 0 qemu-system-arm \
-machine type=virt -nographic -smp 1 -m 4096 \
-netdev user,id=unet,hostfwd=tcp::2222-:22 \
-device virtio-net-device,netdev=unet \
-drive file=jessie.qcow2,id=myblock,index=0,if=none \
-device virtio-blk-device,drive=myblock \
-kernel kernel.img -append console=ttyAMA0 root=/dev/vda1 \
-name arm,debug-threads=on -smp 1' (10 runs):

Before:
18714.917392 task-clock # 0.952 CPUs utilized ( +- 0.95% )
23,142 context-switches # 0.001 M/sec ( +- 0.50% )
1 CPU-migrations # 0.000 M/sec
10,558 page-faults # 0.001 M/sec ( +- 0.95% )
53,957,727,252 cycles # 2.883 GHz ( +- 0.91% ) [83.33%]
24,440,599,852 stalled-cycles-frontend # 45.30% frontend cycles idle ( +- 1.20% ) [83.33%]
16,495,714,424 stalled-cycles-backend # 30.57% backend cycles idle ( +- 0.95% ) [66.66%]
76,267,572,582 instructions # 1.41 insns per cycle
12,692,186,323 branches # 678.186 M/sec ( +- 0.92% ) [83.35%]
263,486,879 branch-misses # 2.08% of all branches ( +- 0.73% ) [83.34%]

19.648474449 seconds time elapsed ( +- 0.82% )

After, w/ inline (this patch):
18471.376627 task-clock # 0.955 CPUs utilized ( +- 0.96% )
23,048 context-switches # 0.001 M/sec ( +- 0.48% )
1 CPU-migrations # 0.000 M/sec
10,708 page-faults # 0.001 M/sec ( +- 0.81% )
53,208,990,796 cycles # 2.881 GHz ( +- 0.98% ) [83.34%]
23,941,071,673 stalled-cycles-frontend # 44.99% frontend cycles idle ( +- 0.95% ) [83.34%]
16,161,773,848 stalled-cycles-backend # 30.37% backend cycles idle ( +- 0.76% ) [66.67%]
75,786,269,766 instructions # 1.42 insns per cycle
12,573,617,143 branches # 680.708 M/sec ( +- 1.34% ) [83.33%]
260,235,550 branch-misses # 2.07% of all branches ( +- 0.66% ) [83.33%]

19.340502161 seconds time elapsed ( +- 0.56% )

After, w/o inline:
18791.253967 task-clock # 0.954 CPUs utilized ( +- 0.78% )
23,230 context-switches # 0.001 M/sec ( +- 0.42% )
1 CPU-migrations # 0.000 M/sec
10,563 page-faults # 0.001 M/sec ( +- 1.27% )
54,168,674,622 cycles # 2.883 GHz ( +- 0.80% ) [83.34%]
24,244,712,629 stalled-cycles-frontend # 44.76% frontend cycles idle ( +- 1.37% ) [83.33%]
16,288,648,572 stalled-cycles-backend # 30.07% backend cycles idle ( +- 0.95% ) [66.66%]
77,659,755,503 instructions # 1.43 insns per cycle
12,922,780,045 branches # 687.702 M/sec ( +- 1.06% ) [83.34%]
261,962,386 branch-misses # 2.03% of all branches ( +- 0.71% ) [83.35%]

19.700174670 seconds time elapsed ( +- 0.56% )

Backports commit f6bb84d53110398f4899c19dab4e0fe9908ec060 from qemu
2018-03-05 02:42:46 -05:00

226 lines
5.3 KiB
C

/*
* Tiny Code Generator for QEMU
*
* Copyright (c) 2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "unicorn/platform.h"
#include "qemu/host-utils.h"
#include "cpu.h"
#include "exec/helper-proto.h"
#include "exec/cpu_ldst.h"
#include "exec/exec-all.h"
#include "exec/tb-lookup.h"
/* 32-bit helpers */
int32_t HELPER(div_i32)(int32_t arg1, int32_t arg2)
{
return arg1 / arg2;
}
int32_t HELPER(rem_i32)(int32_t arg1, int32_t arg2)
{
return arg1 % arg2;
}
uint32_t HELPER(divu_i32)(uint32_t arg1, uint32_t arg2)
{
return arg1 / arg2;
}
uint32_t HELPER(remu_i32)(uint32_t arg1, uint32_t arg2)
{
return arg1 % arg2;
}
/* 64-bit helpers */
uint64_t HELPER(shl_i64)(uint64_t arg1, uint64_t arg2)
{
return arg1 << arg2;
}
uint64_t HELPER(shr_i64)(uint64_t arg1, uint64_t arg2)
{
return arg1 >> arg2;
}
int64_t HELPER(sar_i64)(int64_t arg1, int64_t arg2)
{
return arg1 >> arg2;
}
int64_t HELPER(div_i64)(int64_t arg1, int64_t arg2)
{
return arg1 / arg2;
}
int64_t HELPER(rem_i64)(int64_t arg1, int64_t arg2)
{
return arg1 % arg2;
}
uint64_t HELPER(divu_i64)(uint64_t arg1, uint64_t arg2)
{
return arg1 / arg2;
}
uint64_t HELPER(remu_i64)(uint64_t arg1, uint64_t arg2)
{
return arg1 % arg2;
}
uint64_t HELPER(muluh_i64)(uint64_t arg1, uint64_t arg2)
{
uint64_t l, h;
mulu64(&l, &h, arg1, arg2);
return h;
}
int64_t HELPER(mulsh_i64)(int64_t arg1, int64_t arg2)
{
uint64_t l, h;
muls64(&l, &h, arg1, arg2);
return h;
}
uint32_t HELPER(clz_i32)(uint32_t arg, uint32_t zero_val)
{
return arg ? clz32(arg) : zero_val;
}
uint32_t HELPER(ctz_i32)(uint32_t arg, uint32_t zero_val)
{
return arg ? ctz32(arg) : zero_val;
}
uint64_t HELPER(clz_i64)(uint64_t arg, uint64_t zero_val)
{
return arg ? clz64(arg) : zero_val;
}
uint64_t HELPER(ctz_i64)(uint64_t arg, uint64_t zero_val)
{
return arg ? ctz64(arg) : zero_val;
}
uint32_t HELPER(clrsb_i32)(uint32_t arg)
{
return clrsb32(arg);
}
uint64_t HELPER(clrsb_i64)(uint64_t arg)
{
return clrsb64(arg);
}
uint32_t HELPER(ctpop_i32)(uint32_t arg)
{
return ctpop32(arg);
}
uint64_t HELPER(ctpop_i64)(uint64_t arg)
{
return ctpop64(arg);
}
void *HELPER(lookup_tb_ptr)(CPUArchState *env)
{
TCGContext *tcg_ctx = env->uc->tcg_ctx;
CPUState *cpu = ENV_GET_CPU(env);
TranslationBlock *tb;
target_ulong cs_base, pc;
uint32_t flags;
tb = tb_lookup__cpu_state(cpu, &pc, &cs_base, &flags);
if (tb == NULL) {
return tcg_ctx->code_gen_epilogue;
}
// Unicorn: commented out
//qemu_log_mask_and_addr(CPU_LOG_EXEC, pc,
// "Chain %p [%d: " TARGET_FMT_lx "] %s\n",
// tb->tc_ptr, cpu->cpu_index, pc,
// lookup_symbol(pc));
return tb->tc_ptr;
}
void HELPER(exit_atomic)(CPUArchState *env)
{
cpu_loop_exit_atomic(ENV_GET_CPU(env), GETPC());
}
#ifndef CONFIG_SOFTMMU
/* The softmmu versions of these helpers are in cputlb.c. */
/* Do not allow unaligned operations to proceed. Return the host address. */
static void *atomic_mmu_lookup(CPUArchState *env, target_ulong addr,
int size, uintptr_t retaddr)
{
/* Enforce qemu required alignment. */
if (unlikely(addr & (size - 1))) {
cpu_loop_exit_atomic(ENV_GET_CPU(env), retaddr);
}
return g2h(addr);
}
/* Macro to call the above, with local variables from the use context. */
#define ATOMIC_MMU_LOOKUP atomic_mmu_lookup(env, addr, DATA_SIZE, GETPC())
#define ATOMIC_NAME(X) HELPER(glue(glue(atomic_ ## X, SUFFIX), END))
#define EXTRA_ARGS
#define DATA_SIZE 1
#include "atomic_template.h"
#define DATA_SIZE 2
#include "atomic_template.h"
#define DATA_SIZE 4
#include "atomic_template.h"
#ifdef CONFIG_ATOMIC64
#define DATA_SIZE 8
#include "atomic_template.h"
#endif
/* The following is only callable from other helpers, and matches up
with the softmmu version. */
#ifdef CONFIG_ATOMIC128
#undef EXTRA_ARGS
#undef ATOMIC_NAME
#undef ATOMIC_MMU_LOOKUP
#define EXTRA_ARGS , TCGMemOpIdx oi, uintptr_t retaddr
#define ATOMIC_NAME(X) \
HELPER(glue(glue(glue(atomic_ ## X, SUFFIX), END), _mmu))
#define ATOMIC_MMU_LOOKUP atomic_mmu_lookup(env, addr, DATA_SIZE, retaddr)
#define DATA_SIZE 16
#include "atomic_template.h"
#endif /* CONFIG_ATOMIC128 */
#endif /* !CONFIG_SOFTMMU */