From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44187) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXPsL-0004XM-MH for qemu-devel@nongnu.org; Mon, 16 Mar 2015 03:55:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YXPsH-0003ez-Ke for qemu-devel@nongnu.org; Mon, 16 Mar 2015 03:55:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47760) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXPsH-0003eq-D6 for qemu-devel@nongnu.org; Mon, 16 Mar 2015 03:55:45 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t2G7tiAs020827 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 16 Mar 2015 03:55:44 -0400 Date: Mon, 16 Mar 2015 15:55:40 +0800 From: Fam Zheng Message-ID: <20150316075540.GE15098@ad.nay.redhat.com> References: <1426483910-24597-1-git-send-email-famz@redhat.com> <1426483910-24597-3-git-send-email-famz@redhat.com> <5506872D.9010409@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5506872D.9010409@redhat.com> 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: Paolo Bonzini Cc: qemu-devel@nongnu.org On Mon, 03/16 08:33, Paolo Bonzini wrote: > > > 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? No. Good catch! > > 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). Sounds good, I'll split that patch in v4. Fam > > > 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) > >