On 07/01/2016 05:17 PM, Emilio G. Cota wrote:
On Fri, Jul 01, 2016 at 17:16:09 +0100, Alex Bennée wrote:
From: Sergey Fedorov <serge.f...@gmail.com>
(snip)
@@ -333,7 +338,7 @@ 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_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 eaa95e4..1fcfe79 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -1004,11 +1004,16 @@ void tb_phys_invalidate(TranslationBlock *tb,
tb_page_addr_t page_addr)
invalidate_page_bitmap(p);
}
+ /* Ensure that we won't find the TB in the shared hash table
+ * if we con't see it in CPU's local cache.
s/con't/can't/
+ * Pairs with smp_rmb() in tb_find_slow(). */
+ smp_wmb();
This fence is already embedded in qht_remove, since it internally
calls seqlock_write_end() on a successful removal...
No. There's stuff that happens after qht_remove and before this barrier:
tb_page_remove and invalidate_page_bitmap.
r~
