Commit 16dbaf90 authored by Jason Wang's avatar Jason Wang Committed by Anthony Liguori
Browse files

tap: support enabling or disabling a queue 



This patch introduce a new bit - enabled in TAPState which tracks whether a
specific queue/fd is enabled. The tap/fd is enabled during initialization and
could be enabled/disabled by tap_enalbe() and tap_disable() which calls platform
specific helpers to do the real work. Polling of a tap fd can only done when
the tap was enabled.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent 94fdc6d0

include/net/tap.h

+2 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ int tap_has_vnet_hdr_len(NetClientState *nc, int len); 
void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr);

void tap_set_offload(NetClientState *nc, int csum, int tso4, int tso6, int ecn, int ufo);

void tap_set_vnet_hdr_len(NetClientState *nc, int len);

int tap_enable(NetClientState *nc);

int tap_disable(NetClientState *nc);



int tap_get_fd(NetClientState *nc);

net/tap-win32.c

+10 −0
Original line number Diff line number Diff line
@@ -764,3 +764,13 @@ void tap_set_vnet_hdr_len(NetClientState *nc, int len) 
{

    abort();

}



int tap_enable(NetClientState *nc)

{

    abort();

}



int tap_disable(NetClientState *nc)

{

    abort();

}

net/tap.c

+40 −3
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ typedef struct TAPState { 
    bool write_poll;

    bool using_vnet_hdr;

    bool has_ufo;

    bool enabled;

    VHostNetState *vhost_net;

    unsigned host_vnet_hdr_len;

} TAPState;
@@ -72,9 +73,9 @@ static void tap_writable(void *opaque); 
static void tap_update_fd_handler(TAPState *s)

{

    qemu_set_fd_handler2(s->fd,

                         s->read_poll  ? tap_can_send : NULL,

                         s->read_poll  ? tap_send     : NULL,

                         s->write_poll ? tap_writable : NULL,

                         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);

}
@@ -337,6 +338,7 @@ static TAPState *net_tap_fd_init(NetClientState *peer, 
    s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;

    s->using_vnet_hdr = false;

    s->has_ufo = tap_probe_has_ufo(s->fd);

    s->enabled = true;

    tap_set_offload(&s->nc, 0, 0, 0, 0, 0);

    /*

     * Make sure host header length is set correctly in tap:
@@ -735,3 +737,38 @@ VHostNetState *tap_get_vhost_net(NetClientState *nc) 
    assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP);

    return s->vhost_net;

}



int tap_enable(NetClientState *nc)

{

    TAPState *s = DO_UPCAST(TAPState, nc, nc);

    int ret;



    if (s->enabled) {

        return 0;

    } else {

        ret = tap_fd_enable(s->fd);

        if (ret == 0) {

            s->enabled = true;

            tap_update_fd_handler(s);

        }

        return ret;

    }

}



int tap_disable(NetClientState *nc)

{

    TAPState *s = DO_UPCAST(TAPState, nc, nc);

    int ret;



    if (s->enabled == 0) {

        return 0;

    } else {

        ret = tap_fd_disable(s->fd);

        if (ret == 0) {

            qemu_purge_queued_packets(nc);

            s->enabled = false;

            tap_update_fd_handler(s);

        }

        return ret;

    }

}