On Thu, Sep 02, 2021 at 03:09:15PM +0200, Richard Henderson wrote:
> On 8/31/21 2:15 PM, Gerd Hoffmann wrote:
> > diff --git a/target/i386/helper.c b/target/i386/helper.c
> > index 533b29cb91b6..100add713c5d 100644
> > --- a/target/i386/helper.c
> > +++ b/target/i386/helper.c
> > @@ -103,7 +103,7 @@ void x86_cpu_set_a20(X86CPU *cpu, int a20_state)
> > /* when a20 is changed, all the MMU mappings are invalid, so
> > we must flush everything */
> > - tlb_flush(cs);
> > + tcg.tlb_flush(cs);
>
> I think this is a mistake.
>
> (1) If tcg module is not enabled, we should be able to make a direct call.
>
> So IMO we want to retain the direct function call syntax in all the uses. I
> think you want to put wrapper functions doing the indirection somewhere --
> possibly tcg-module.c.
Hmm, when we want avoid indirection I guess it makes sense to use inline
wrappers in tcg-module.h
How about the patch below? (proof-of-concept for tlb_flush, on top of
this series)?
thanks,
Gerd
>From 22f5a216f410fccb769d0f7496c3c36f4b131833 Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kra...@redhat.com>
Date: Tue, 28 Sep 2021 11:51:12 +0200
Subject: [PATCH] tlb_flush inline wrapper
---
include/exec/exec-all.h | 2 ++
include/tcg/tcg-module.h | 13 +++++++++++++
meson.build | 3 ++-
3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 608d768a4371..72e4e3b5bb89 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -160,7 +160,9 @@ void tlb_flush_page_all_cpus_synced(CPUState *src,
target_ulong addr);
* so this is generally safe. If more selective flushing is required
* use one of the other functions for efficiency.
*/
+#ifdef TCG_DIRECT_CALL
void tlb_flush(CPUState *cpu);
+#endif
/**
* tlb_flush_all_cpus:
* @cpu: src CPU of the flush
diff --git a/include/tcg/tcg-module.h b/include/tcg/tcg-module.h
index e9c0615b51d9..b3c0f53ea9f3 100644
--- a/include/tcg/tcg-module.h
+++ b/include/tcg/tcg-module.h
@@ -1,6 +1,10 @@
#ifndef TCG_MODULE_H
#define TCG_MODULE_H
+#if defined(CONFIG_TCG_BUILTIN) || defined(TCG_MODULE)
+# define TCG_DIRECT_CALL 1
+#endif
+
#include "exec/exec-all.h"
struct TCGModuleOps {
@@ -21,4 +25,13 @@ struct TCGModuleOps {
};
extern struct TCGModuleOps tcg;
+#ifndef TCG_DIRECT_CALL
+
+static inline void tlb_flush(CPUState *cpu)
+{
+ tcg.tlb_flush(cpu);
+}
+
+#endif
+
#endif /* TCG_MODULE_H */
diff --git a/meson.build b/meson.build
index 15ef4d3c4187..afe07e7d59c3 100644
--- a/meson.build
+++ b/meson.build
@@ -2317,8 +2317,9 @@ subdir('tests/qtest/libqos')
subdir('tests/qtest/fuzz')
# accel modules
+tcg_module_cflags = declare_dependency(compile_args: '-DTCG_MODULE=1')
tcg_real_module_ss = ss.source_set()
-tcg_real_module_ss.add_all(when: 'CONFIG_TCG_MODULAR', if_true: tcg_module_ss)
+tcg_real_module_ss.add_all(when: ['CONFIG_TCG_MODULAR', tcg_module_cflags],
if_true: tcg_module_ss)
specific_ss.add_all(when: 'CONFIG_TCG_BUILTIN', if_true: tcg_module_ss)
target_modules += { 'accel' : { 'qtest': qtest_module_ss,
'tcg': tcg_real_module_ss }}
--
2.31.1
