Merge remote-tracking branch 'remotes/rth-gitlab/tags/pull-tcg-20210613' into staging

Clean up code_gen_buffer allocation.
Add tcg_remove_ops_after.
Fix tcg_constant_* documentation.
Improve TB chaining documentation.
Fix float32_exp2.
Fix arm tcg_out_op function signature.

# gpg: Signature made Mon 14 Jun 2021 02:12:35 BST
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "[email protected]"
# gpg: Good signature from "Richard Henderson <[email protected]>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* remotes/rth-gitlab/tags/pull-tcg-20210613: (34 commits)
  docs/devel: Explain in more detail the TB chaining mechanisms
  softfloat: Fix tp init in float32_exp2
  tcg/arm: Fix tcg_out_op function signature
  tcg: Fix documentation for tcg_constant_* vs tcg_temp_free_*
  tcg: Introduce tcg_remove_ops_after
  tcg: Move tcg_init_ctx and tcg_ctx from accel/tcg/
  tcg: When allocating for !splitwx, begin with PROT_NONE
  tcg: Merge buffer protection and guard page protection
  tcg: Round the tb_size default from qemu_get_host_physmem
  util/osdep: Add qemu_mprotect_rw
  tcg: Sink qemu_madvise call to common code
  tcg: Return the map protection from alloc_code_gen_buffer
  tcg: Allocate code_gen_buffer into struct tcg_region_state
  tcg: Move in_code_gen_buffer and tests to region.c
  tcg: Tidy split_cross_256mb
  tcg: Tidy tcg_n_regions
  tcg: Rename region.start to region.after_prologue
  tcg: Replace region.end with region.total_size
  tcg: Move MAX_CODE_GEN_BUFFER_SIZE to tcg-target.h
  tcg: Introduce tcg_max_ctxs
  ...

Signed-off-by: Peter Maydell <[email protected]>

Author: pm215

accel/tcg/internal.h

@@ -16,5 +16,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu, target_ulong pc,
                               int cflags);
 
 void QEMU_NORETURN cpu_io_recompile(CPUState *cpu, uintptr_t retaddr);
+void page_init(void);
+void tb_htable_init(void);
 
 #endif /* ACCEL_TCG_INTERNAL_H */

accel/tcg/tcg-all.c

@@ -32,6 +32,11 @@
 #include "qemu/error-report.h"
 #include "qemu/accel.h"
 #include "qapi/qapi-builtin-visit.h"
+#include "qemu/units.h"
+#if !defined(CONFIG_USER_ONLY)
+#include "hw/boards.h"
+#endif
+#include "internal.h"
 
 struct TCGState {
     AccelState parent_obj;
@@ -105,22 +110,29 @@ static void tcg_accel_instance_init(Object *obj)
 
 bool mttcg_enabled;
 
-static int tcg_init(MachineState *ms)
+static int tcg_init_machine(MachineState *ms)
 {
     TCGState *s = TCG_STATE(current_accel());
+#ifdef CONFIG_USER_ONLY
+    unsigned max_cpus = 1;
+#else
+    unsigned max_cpus = ms->smp.max_cpus;
+#endif
 
-    tcg_exec_init(s->tb_size * 1024 * 1024, s->splitwx_enabled);
+    tcg_allowed = true;
     mttcg_enabled = s->mttcg_enabled;
 
+    page_init();
+    tb_htable_init();
+    tcg_init(s->tb_size * MiB, s->splitwx_enabled, max_cpus);
+
+#if defined(CONFIG_SOFTMMU)
     /*
-     * Initialize TCG regions only for softmmu.
-     *
-     * This needs to be done later for user mode, because the prologue
-     * generation needs to be delayed so that GUEST_BASE is already set.
+     * There's no guest base to take into account, so go ahead and
+     * initialize the prologue now.
      */
-#ifndef CONFIG_USER_ONLY
-    tcg_region_init();
-#endif /* !CONFIG_USER_ONLY */
+    tcg_prologue_init(tcg_ctx);
+#endif
 
     return 0;
 }
@@ -200,7 +212,7 @@ static void tcg_accel_class_init(ObjectClass *oc, void *data)
 {
     AccelClass *ac = ACCEL_CLASS(oc);
     ac->name = "tcg";
-    ac->init_machine = tcg_init;
+    ac->init_machine = tcg_init_machine;
     ac->allowed = &tcg_allowed;
 
     object_class_property_add_str(oc, "thread",