From 33b6c2edf6214f02b9beaea61b169506c01f90aa Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Mon, 16 Mar 2015 17:03:36 +0800 Subject: [PATCH] exec: Notify cpu_register_map_client caller if the bounce buffer is available The caller's workflow is like if (!address_space_map()) { ... cpu_register_map_client(); } If bounce buffer became available after address_space_map() but before cpu_register_map_client(), the caller could miss it and has to wait for the next bounce buffer notify, which may never happen in the worse case. Just notify the list in cpu_register_map_client(). Signed-off-by: Fam Zheng Message-Id: <1426496617-10702-5-git-send-email-famz@redhat.com> Signed-off-by: Paolo Bonzini --- exec.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/exec.c b/exec.c index 81666d3d6d..2c87f1d6d6 100644 --- a/exec.c +++ b/exec.c @@ -2488,6 +2488,18 @@ QemuMutex map_client_list_lock; static QLIST_HEAD(map_client_list, MapClient) map_client_list = QLIST_HEAD_INITIALIZER(map_client_list); +static void cpu_unregister_map_client(void *_client); +static void cpu_notify_map_clients_locked(void) +{ + MapClient *client; + + while (!QLIST_EMPTY(&map_client_list)) { + client = QLIST_FIRST(&map_client_list); + client->callback(client->opaque); + cpu_unregister_map_client(client); + } +} + void *cpu_register_map_client(void *opaque, void (*callback)(void *opaque)) { MapClient *client = g_malloc(sizeof(*client)); @@ -2496,6 +2508,9 @@ void *cpu_register_map_client(void *opaque, void (*callback)(void *opaque)) client->opaque = opaque; client->callback = callback; QLIST_INSERT_HEAD(&map_client_list, client, link); + if (!atomic_read(&bounce.in_use)) { + cpu_notify_map_clients_locked(); + } qemu_mutex_unlock(&map_client_list_lock); return client; } @@ -2518,14 +2533,8 @@ static void cpu_unregister_map_client(void *_client) 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); - cpu_unregister_map_client(client); - } + cpu_notify_map_clients_locked(); qemu_mutex_unlock(&map_client_list_lock); }