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[Qemu-devel] [PULL 05/58] tcg: Prepare safe tb_jmp_cache lookup out of t
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 05/58] tcg: Prepare safe tb_jmp_cache lookup out of tb_lock |
Date: |
Tue, 13 Sep 2016 19:15:36 +0200 |
From: Sergey Fedorov <address@hidden>
Ensure atomicity of CPU's 'tb_jmp_cache' access for future translation
block lookup out of 'tb_lock'.
Note that this patch does *not* make CPU's TLB invalidation safe if it
is done from some other thread while the CPU is in its execution loop.
Signed-off-by: Alex Bennée <address@hidden>
Signed-off-by: Sergey Fedorov <address@hidden>
Signed-off-by: Sergey Fedorov <address@hidden>
Reviewed-by: Alex Bennée <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
cpu-exec.c | 4 ++--
translate-all.c | 10 +++++++---
2 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/cpu-exec.c b/cpu-exec.c
index cf511f1..32b58ed 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -315,7 +315,7 @@ static TranslationBlock *tb_find_slow(CPUState *cpu,
found:
/* we add the TB in the virtual pc hash table */
- cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)] = tb;
+ atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)], tb);
return tb;
}
@@ -333,7 +333,7 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu,
is executed. */
cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
tb_lock();
- tb = cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)];
+ tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]);
if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base ||
tb->flags != flags)) {
tb = tb_find_slow(cpu, pc, cs_base, flags);
diff --git a/translate-all.c b/translate-all.c
index 0dd6466..77ae59d 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -851,7 +851,11 @@ void tb_flush(CPUState *cpu)
tcg_ctx.tb_ctx.nb_tbs = 0;
CPU_FOREACH(cpu) {
- memset(cpu->tb_jmp_cache, 0, sizeof(cpu->tb_jmp_cache));
+ int i;
+
+ for (i = 0; i < TB_JMP_CACHE_SIZE; ++i) {
+ atomic_set(&cpu->tb_jmp_cache[i], NULL);
+ }
cpu->tb_flushed = true;
}
@@ -1010,8 +1014,8 @@ void tb_phys_invalidate(TranslationBlock *tb,
tb_page_addr_t page_addr)
/* remove the TB from the hash list */
h = tb_jmp_cache_hash_func(tb->pc);
CPU_FOREACH(cpu) {
- if (cpu->tb_jmp_cache[h] == tb) {
- cpu->tb_jmp_cache[h] = NULL;
+ if (atomic_read(&cpu->tb_jmp_cache[h]) == tb) {
+ atomic_set(&cpu->tb_jmp_cache[h], NULL);
}
}
--
1.8.3.1
- [Qemu-devel] [PULL 00/58] First round of misc patches for QEMU 2.8, Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 01/58] qtail: clean up direct access to tqe_prev field, Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 04/58] tcg: Pass last_tb by value to tb_find_fast(), Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 03/58] util: fix some coding style issue, Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 05/58] tcg: Prepare safe tb_jmp_cache lookup out of tb_lock,
Paolo Bonzini <=
- [Qemu-devel] [PULL 08/58] tcg: set up tb->page_addr before insertion, Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 02/58] util/qemu-sockets: revert Yoda Conditions to normal, Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 07/58] tcg: Prepare TB invalidation for lockless TB lookup, Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 11/58] tcg: Merge tb_find_slow() and tb_find_fast(), Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 09/58] tcg: cpu-exec: remove tb_lock from the hot-path, Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 12/58] tcg: rename tb_find_physical(), Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 06/58] tcg: Prepare safe access to tb_flushed out of tb_lock, Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 10/58] tcg: Avoid bouncing tb_lock between tb_gen_code() and tb_add_jump(), Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 13/58] rules.mak: Don't extract libs from .mo-libs in link command, Paolo Bonzini, 2016/09/13
- [Qemu-devel] [PULL 14/58] timer: update comments, Paolo Bonzini, 2016/09/13