From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40022) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXPWT-00031B-6e for qemu-devel@nongnu.org; Mon, 16 Mar 2015 03:33:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YXPWM-0004iu-FV for qemu-devel@nongnu.org; Mon, 16 Mar 2015 03:33:13 -0400 Received: from mail-wg0-x22e.google.com ([2a00:1450:400c:c00::22e]:35705) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXPWM-0004im-8v for qemu-devel@nongnu.org; Mon, 16 Mar 2015 03:33:06 -0400 Received: by wgdm6 with SMTP id m6so32371127wgd.2 for ; Mon, 16 Mar 2015 00:33:05 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <5506872D.9010409@redhat.com> Date: Mon, 16 Mar 2015 08:33:01 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1426483910-24597-1-git-send-email-famz@redhat.com> <1426483910-24597-3-git-send-email-famz@redhat.com> In-Reply-To: <1426483910-24597-3-git-send-email-famz@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 2/4] exec: Protect map_client_list with mutex List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng , qemu-devel@nongnu.org On 16/03/2015 06:31, Fam Zheng wrote: > So that accesses from multiple threads are safe. > > Signed-off-by: Fam Zheng > --- > exec.c | 24 +++++++++++++++--------- > 1 file changed, 15 insertions(+), 9 deletions(-) > > diff --git a/exec.c b/exec.c > index 4080044..3e54580 100644 > --- a/exec.c > +++ b/exec.c > @@ -429,15 +429,6 @@ address_space_translate_for_iotlb(CPUState *cpu, hwaddr addr, > } > #endif > > -void cpu_exec_init_all(void) > -{ > -#if !defined(CONFIG_USER_ONLY) > - qemu_mutex_init(&ram_list.mutex); > - memory_map_init(); > - io_mem_init(); > -#endif > -} > - > #if !defined(CONFIG_USER_ONLY) > > static int cpu_common_post_load(void *opaque, int version_id) > @@ -2494,6 +2485,7 @@ typedef struct MapClient { > QLIST_ENTRY(MapClient) link; > } MapClient; > > +QemuMutex map_client_list_lock; > static QLIST_HEAD(map_client_list, MapClient) map_client_list > = QLIST_HEAD_INITIALIZER(map_client_list); > > @@ -2501,12 +2493,24 @@ void *cpu_register_map_client(void *opaque, void (*callback)(void *opaque)) > { > MapClient *client = g_malloc(sizeof(*client)); > > + qemu_mutex_lock(&map_client_list_lock); > client->opaque = opaque; > client->callback = callback; > QLIST_INSERT_HEAD(&map_client_list, client, link); > + qemu_mutex_unlock(&map_client_list_lock); > return client; > } > > +void cpu_exec_init_all(void) > +{ > +#if !defined(CONFIG_USER_ONLY) > + qemu_mutex_init(&ram_list.mutex); > + memory_map_init(); > + io_mem_init(); > +#endif > + qemu_mutex_init(&map_client_list_lock); > +} > + You are moving cpu_exec_init_all within an #ifndef CONFIG_USER_ONLY. Does this patch compile for user-mode emulation? The move itself is okay but only if you remove the two calls in *-user/main.c (and possibly move the prototype to include/exec/exec-all.h). > static void cpu_unregister_map_client(void *_client) > { > MapClient *client = (MapClient *)_client; > @@ -2519,11 +2523,13 @@ static void cpu_notify_map_clients(void) > { > MapClient *client; > > + qemu_mutex_lock(&map_client_list_lock); > while (!QLIST_EMPTY(&map_client_list)) { > client = QLIST_FIRST(&map_client_list); > client->callback(client->opaque); A good rule of thumb is never hold a lock while calling "unknown" code. This will be fixed in patch 4, so it's okay. Paolo > cpu_unregister_map_client(client); > } > + qemu_mutex_unlock(&map_client_list_lock); > } > > bool address_space_access_valid(AddressSpace *as, hwaddr addr, int len, bool is_write) >