From: Jay Zhou <jianjay.z...@huawei.com> If netdev_add tap,id=net0,...,vhost=on failed in net_init_tap_one(), the followed up device_add virtio-net-pci,netdev=net0 will fail too, prints:
TUNSETOFFLOAD ioctl() failed: Bad file descriptor TUNSETOFFLOAD ioctl() failed: Bad file descriptor The reason is that the fd of tap is closed when error occured after calling net_init_tap_one(). The fd should be closed when calling net_init_tap_one failed: - if tap_set_sndbuf() failed - if tap_set_sndbuf() succeeded but vhost failed to open or initialize with vhostforce flag on - with wrong vhost command line parameter The fd should not be closed just because vhost failed to open or initialize but without vhostforce flag. So the followed up device_add can fall back to userspace virtio successfully. Suggested-by: Michael S. Tsirkin <m...@redhat.com> Suggested-by: Igor Mammedov <imamm...@redhat.com> Suggested-by: Jason Wang <jasow...@redhat.com> Signed-off-by: Jay Zhou <jianjay.z...@huawei.com> Signed-off-by: Jason Wang <jasow...@redhat.com> --- include/net/vhost_net.h | 3 +++ net/tap.c | 22 +++++++++++++++++----- 2 files changed, 20 insertions(+), 5 deletions(-) diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h index afc1499..77e4739 100644 --- a/include/net/vhost_net.h +++ b/include/net/vhost_net.h @@ -4,6 +4,9 @@ #include "net/net.h" #include "hw/virtio/vhost-backend.h" +#define VHOST_NET_INIT_FAILED \ + "vhost-net requested but could not be initialized" + struct vhost_net; typedef struct vhost_net VHostNetState; diff --git a/net/tap.c b/net/tap.c index 979e622..2b3a36f 100644 --- a/net/tap.c +++ b/net/tap.c @@ -686,14 +686,23 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, if (vhostfdname) { vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err); if (vhostfd == -1) { - error_propagate(errp, err); + if (tap->has_vhostforce && tap->vhostforce) { + error_propagate(errp, err); + } else { + warn_report_err(err); + } return; } } else { vhostfd = open("/dev/vhost-net", O_RDWR); if (vhostfd < 0) { - error_setg_errno(errp, errno, - "tap: open vhost char device failed"); + if (tap->has_vhostforce && tap->vhostforce) { + error_setg_errno(errp, errno, + "tap: open vhost char device failed"); + } else { + warn_report("tap: open vhost char device failed: %s", + strerror(errno)); + } return; } fcntl(vhostfd, F_SETFL, O_NONBLOCK); @@ -702,8 +711,11 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer, s->vhost_net = vhost_net_init(&options); if (!s->vhost_net) { - error_setg(errp, - "vhost-net requested but could not be initialized"); + if (tap->has_vhostforce && tap->vhostforce) { + error_setg(errp, VHOST_NET_INIT_FAILED); + } else { + warn_report(VHOST_NET_INIT_FAILED); + } return; } } else if (vhostfdname) { -- 2.7.4