tcg: Move tb_phys_invalidate_count to tb_ctx

We can call do_tb_phys_invalidate from an iocontext, which has
no per-thread tcg_ctx.  Move this to tb_ctx, which is global.
The actual update still takes place with a lock held, so only
an atomic set is required, not an atomic increment.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/457
Tested-by: Viktor Ashirov <vashirov@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

accel/tcg/tb-context.h

@@ -34,6 +34,7 @@ struct TBContext {
 
     /* statistics */
     unsigned tb_flush_count;
+    unsigned tb_phys_invalidate_count;
 };
 
 extern TBContext tb_ctx;

accel/tcg/translate-all.c

@@ -1219,8 +1219,8 @@ static void do_tb_phys_invalidate(TranslationBlock *tb, bool rm_from_page_list)
     /* suppress any remaining jumps to this TB */
     tb_jmp_unlink(tb);
 
-    qatomic_set(&tcg_ctx->tb_phys_invalidate_count,
-               tcg_ctx->tb_phys_invalidate_count + 1);
+    qatomic_set(&tb_ctx.tb_phys_invalidate_count,
+                tb_ctx.tb_phys_invalidate_count + 1);
 }
 
 static void tb_phys_invalidate__locked(TranslationBlock *tb)
@@ -2128,8 +2128,8 @@ void dump_exec_info(void)
     qemu_printf("\nStatistics:\n");
     qemu_printf("TB flush count      %u\n",
                 qatomic_read(&tb_ctx.tb_flush_count));
-    qemu_printf("TB invalidate count %zu\n",
-                tcg_tb_phys_invalidate_count());
+    qemu_printf("TB invalidate count %u\n",
+                qatomic_read(&tb_ctx.tb_phys_invalidate_count));
 
     tlb_flush_counts(&flush_full, &flush_part, &flush_elide);
     qemu_printf("TLB full flushes    %zu\n", flush_full);

include/tcg/tcg.h

@@ -579,8 +579,6 @@ struct TCGContext {
     /* Threshold to flush the translated code buffer.  */
     void *code_gen_highwater;
 
-    size_t tb_phys_invalidate_count;
-
     /* Track which vCPU triggers events */
     CPUState *cpu;                      /* *_trans */
 
@@ -815,7 +813,6 @@ size_t tcg_code_capacity(void);
 
 void tcg_tb_insert(TranslationBlock *tb);
 void tcg_tb_remove(TranslationBlock *tb);
-size_t tcg_tb_phys_invalidate_count(void);
 TranslationBlock *tcg_tb_lookup(uintptr_t tc_ptr);
 void tcg_tb_foreach(GTraverseFunc func, gpointer user_data);
 size_t tcg_nb_tbs(void);

tcg/region.c

@@ -980,17 +980,3 @@ size_t tcg_code_capacity(void)
 
     return capacity;
 }
-
-size_t tcg_tb_phys_invalidate_count(void)
-{
-    unsigned int n_ctxs = qatomic_read(&tcg_cur_ctxs);
-    unsigned int i;
-    size_t total = 0;
-
-    for (i = 0; i < n_ctxs; i++) {
-        const TCGContext *s = qatomic_read(&tcg_ctxs[i]);
-
-        total += qatomic_read(&s->tb_phys_invalidate_count);
-    }
-    return total;
-}