diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2016-07-19 08:36:18 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-09-13 19:08:43 +0200 |
| commit | 6d21e4208f382dd8ca1f7995a6dd9ea7ca281163 (patch) | |
| tree | 81569f437586f0525ac788a09826af4e0c8020bb | |
| parent | 118b07308a8cedc16ef63d7ab243a95f1701db40 (diff) | |
tcg: Prepare TB invalidation for lockless TB lookup
When invalidating a translation block, set an invalid flag into the
TranslationBlock structure first. It is also necessary to check whether
the target TB is still valid after acquiring 'tb_lock' but before calling
tb_add_jump() since TB lookup is to be performed out of 'tb_lock' in
future. Note that we don't have to check 'last_tb'; an already invalidated
TB will not be executed anyway and it is thus safe to patch it.
Suggested-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | cpu-exec.c | 5 | ||||
| -rw-r--r-- | include/exec/exec-all.h | 2 | ||||
| -rw-r--r-- | translate-all.c | 3 |
3 files changed, 8 insertions, 2 deletions
diff --git a/cpu-exec.c b/cpu-exec.c index 877ff8ed70..cdaab1dbcd 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -241,7 +241,8 @@ static bool tb_cmp(const void *p, const void *d) if (tb->pc == desc->pc && tb->page_addr[0] == desc->phys_page1 && tb->cs_base == desc->cs_base && - tb->flags == desc->flags) { + tb->flags == desc->flags && + !atomic_read(&tb->invalid)) { /* check next page if needed */ if (tb->page_addr[1] == -1) { return true; @@ -352,7 +353,7 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu, /* Check if translation buffer has been flushed */ if (cpu->tb_flushed) { cpu->tb_flushed = false; - } else { + } else if (!tb->invalid) { tb_add_jump(last_tb, tb_exit, tb); } } diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index d008296c1b..a0e87be88f 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -225,6 +225,8 @@ struct TranslationBlock { #define CF_USE_ICOUNT 0x20000 #define CF_IGNORE_ICOUNT 0x40000 /* Do not generate icount code */ + uint16_t invalid; + void *tc_ptr; /* pointer to the translated code */ uint8_t *tc_search; /* pointer to search data */ /* original tb when cflags has CF_NOCACHE */ diff --git a/translate-all.c b/translate-all.c index e753a50640..5a5499ffb6 100644 --- a/translate-all.c +++ b/translate-all.c @@ -773,6 +773,7 @@ static TranslationBlock *tb_alloc(target_ulong pc) tb = &tcg_ctx.tb_ctx.tbs[tcg_ctx.tb_ctx.nb_tbs++]; tb->pc = pc; tb->cflags = 0; + tb->invalid = false; return tb; } @@ -994,6 +995,8 @@ void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr) uint32_t h; tb_page_addr_t phys_pc; + atomic_set(&tb->invalid, true); + /* remove the TB from the hash list */ phys_pc = tb->page_addr[0] + (tb->pc & ~TARGET_PAGE_MASK); h = tb_hash_func(phys_pc, tb->pc, tb->flags); |