[Qemu-devel] [RFC PATCH v5 03/14] net: port tap onto GSource

[Liu Ping Fan]

From: Liu Ping Fan <pingf...@linux.vnet.ibm.com>

Signed-off-by: Liu Ping Fan <pingf...@linux.vnet.ibm.com>
---
 net/tap.c |   64 +++++++++++++++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 54 insertions(+), 10 deletions(-)

diff --git a/net/tap.c b/net/tap.c
index daab350..5f4d59f 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -41,6 +41,7 @@
 #include "qemu/error-report.h"
 
 #include "net/tap.h"
+#include "util/event_gsource.h"
 
 #include "hw/vhost_net.h"
 
@@ -62,6 +63,7 @@ typedef struct TAPState {
     bool enabled;
     VHostNetState *vhost_net;
     unsigned host_vnet_hdr_len;
+    EventGSource *nsrc;
 } TAPState;
 
 static int launch_script(const char *setup_script, const char *ifname, int fd);
@@ -70,25 +72,48 @@ static int tap_can_send(void *opaque);
 static void tap_send(void *opaque);
 static void tap_writable(void *opaque);
 
-static void tap_update_fd_handler(TAPState *s)
+static gushort readable(void *opaque)
 {
-    qemu_set_fd_handler2(s->fd,
-                         s->read_poll && s->enabled ? tap_can_send : NULL,
-                         s->read_poll && s->enabled ? tap_send     : NULL,
-                         s->write_poll && s->enabled ? tap_writable : NULL,
-                         s);
+    TAPState *s = opaque;
+
+    if (s->enabled && s->read_poll &&
+        tap_can_send(s)) {
+        return G_IO_IN;
+    }
+    return 0;
+}
+
+static gushort writable(void *opaque)
+{
+    TAPState *s = opaque;
+
+    if (s->enabled && s->write_poll) {
+        return G_IO_OUT;
+    }
+    return 0;
+}
+
+static gboolean tap_handler(gpointer data)
+{
+    EventGSource *nsrc = data;
+
+    if (nsrc->gfd.revents & G_IO_IN) {
+        tap_send(nsrc->opaque);
+    }
+    if (nsrc->gfd.revents & G_IO_OUT) {
+        tap_writable(nsrc->opaque);
+    }
+    return true;
 }
 
 static void tap_read_poll(TAPState *s, bool enable)
 {
     s->read_poll = enable;
-    tap_update_fd_handler(s);
 }
 
 static void tap_write_poll(TAPState *s, bool enable)
 {
     s->write_poll = enable;
-    tap_update_fd_handler(s);
 }
 
 static void tap_writable(void *opaque)
@@ -291,6 +316,7 @@ static void tap_cleanup(NetClientState *nc)
 
     tap_read_poll(s, false);
     tap_write_poll(s, false);
+    event_source_release(s->nsrc);
     close(s->fd);
     s->fd = -1;
 }
@@ -300,6 +326,12 @@ static void tap_poll(NetClientState *nc, bool enable)
     TAPState *s = DO_UPCAST(TAPState, nc, nc);
     tap_read_poll(s, enable);
     tap_write_poll(s, enable);
+
+    if (!enable) {
+        g_source_remove_poll(&s->nsrc->source, &s->nsrc->gfd);
+    } else {
+        g_source_add_poll(&s->nsrc->source, &s->nsrc->gfd);
+    }
 }
 
 int tap_get_fd(NetClientState *nc)
@@ -309,6 +341,13 @@ int tap_get_fd(NetClientState *nc)
     return s->fd;
 }
 
+static void tap_bind_ctx(NetClientState *nc, GMainContext *ctx)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    g_source_attach(&s->nsrc->source, ctx);
+}
+
 /* fd support */
 
 static NetClientInfo net_tap_info = {
@@ -319,6 +358,7 @@ static NetClientInfo net_tap_info = {
     .receive_iov = tap_receive_iov,
     .poll = tap_poll,
     .cleanup = tap_cleanup,
+    .bind_ctx = tap_bind_ctx,
 };
 
 static TAPState *net_tap_fd_init(NetClientState *peer,
@@ -596,6 +636,7 @@ static int net_init_tap_one(const NetdevTapOptions *tap, 
NetClientState *peer,
                             int vnet_hdr, int fd)
 {
     TAPState *s;
+    EventGSource *nsrc;
 
     s = net_tap_fd_init(peer, model, name, fd, vnet_hdr);
     if (!s) {
@@ -606,6 +647,11 @@ static int net_init_tap_one(const NetdevTapOptions *tap, 
NetClientState *peer,
     if (tap_set_sndbuf(s->fd, tap) < 0) {
         return -1;
     }
+    nsrc = event_source_new(s->fd, tap_handler, s);
+    nsrc->readable = readable;
+    nsrc->writable = writable;
+    s->nsrc = nsrc;
+    s->nc.info->bind_ctx(&s->nc, NULL);
 
     if (tap->has_fd || tap->has_fds) {
         snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
@@ -844,7 +890,6 @@ int tap_enable(NetClientState *nc)
         ret = tap_fd_enable(s->fd);
         if (ret == 0) {
             s->enabled = true;
-            tap_update_fd_handler(s);
         }
         return ret;
     }
@@ -862,7 +907,6 @@ int tap_disable(NetClientState *nc)
         if (ret == 0) {
             qemu_purge_queued_packets(nc);
             s->enabled = false;
-            tap_update_fd_handler(s);
         }
         return ret;
     }
-- 
1.7.4.4