net: tap: using bool instead of bitfield

Signed-off-by: Jason Wang <jasowang@redhat.com>
net: tap: use abort() instead of assert(0)

Signed-off-by: Jason Wang <jasowang@redhat.com>
net: introduce qemu_get_queue()

To support multiqueue, the patch introduce a helper qemu_get_queue()
which is used to get the NetClientState of a device. The following patches would
refactor this helper to support multiqueue.

Signed-off-by: Jason Wang <jasowang@redhat.com>
net: introduce qemu_get_nic()

To support multiqueue, this patch introduces a helper qemu_get_nic() to get
NICState from a NetClientState. The following patches would refactor this helper
to support multiqueue.

Signed-off-by: Jason Wang <jasowang@redhat.com>
net: intorduce qemu_del_nic()

To support multiqueue nic, this patch separate the nic destructor from
qemu_del_net_client() to a new helper qemu_del_nic() since the mapping bettween
NiCState and NetClientState were not 1:1 in multiqueue. The following patches
would refactor this function to support multiqueue nic.

Signed-off-by: Jason Wang <jasowang@redhat.com>
net: introduce qemu_find_net_clients_except()

In multiqueue, all NetClientState that belongs to the same netdev or nic has the
same id. So this patches introduces an helper qemu_find_net_clients_except()
which finds all NetClientState with the same id. This will be used by multiqueue
networking.

Signed-off-by: Jason Wang <jasowang@redhat.com>
net: introduce qemu_net_client_setup()

This patch separates the setup of NetClientState from its allocation, this will
allow allocating an arrays of NetClientState and does the initialization one by
one which is what multiqueue needs.

Signed-off-by: Jason Wang <jasowang@redhat.com>
net: introduce NetClientState destructor

To allow allocating an array of NetClientState and free it once, this patch
introduces destructor of NetClientState. Which could do type specific free,
which could be used by multiqueue to free the array once.

Signed-off-by: Jason Wang <jasowang@redhat.com>
net: multiqueue support

This patch adds basic multiqueue support for qemu. The idea is simple, an array
of NetClientStates were introduced in NICState, parse_netdev() were extended to
find and match all NetClientStates belongs to the backend and place their
pointers in NICConf. Then qemu_new_nic can setup a N:N mapping between NICStates
that belongs to a nic and NICStates belongs to the netdev. And a queue_index
were introduced in NetClientState to track its index. After this, each peers of
a NICState were abstracted as a queue.

After this change, all NetClientState that belongs to the same backend/nic has
the same id. When use want to change the link status, all NetClientStates that
belongs to the same backend/nic will be also changed. When user want to delete
a device or netdev, all NetClientStates that belongs to the same backend/nic
will be deleted also. Changing or deleting an specific queue is not allowed.

Signed-off-by: Jason Wang <jasowang@redhat.com>
tap: import linux multiqueue constants

Import multiqueue constants from if_tun.h from 3.8-rc3. A new ifr flag
IFF_MULTI_QUEUE were introduced to create a multiqueue backend by calling
TUNSETIFF with the this flag and with the same interface name many times.

A new ioctl TUNSETQUEUE were introduced. When doing this ioctl with
IFF_DETACH_QUEUE, the queue were disabled in the linux kernel. When doing this
ioctl with IFF_ATTACH_QUEUE, the queue were enabled in the linux kernel.

Signed-off-by: Jason Wang <jasowang@redhat.com>
tap: factor out common tap initialization

This patch factors out the common initialization of tap into a new helper
net_init_tap_one(). This will be used by multiqueue tap patches.

Signed-off-by: Jason Wang <jasowang@redhat.com>
tap: add Linux multiqueue support

This patch add basic multiqueue support for Linux. When multiqueue is needed, we
will first check whether kernel support multiqueue tap before creating more
queues. Two new functions tap_fd_enable() and tap_fd_disable() were introduced
to enable and disable a specific queue. Since the multiqueue is only supported
in Linux, return error on other platforms.

Signed-off-by: Jason Wang <jasowang@redhat.com>
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: Jason Wang <jasowang@redhat.com>
tap: introduce a helper to get the name of an interface

This patch introduces a helper tap_get_ifname() to get the device name of tap
device. This is needed when ifname is unspecified in the command line and qemu
were asked to create tap device by itself. In this situation, the name were
allocated by kernel, so if multiqueue is asked, we need to fetch its name after
creating the first queue.

Only linux has this support since it's the only platform that supports
multiqueue tap.

Signed-off-by: Jason Wang <jasowang@redhat.com>
tap: multiqueue support

Recently, linux support multiqueue tap which could let userspace call TUNSETIFF
for a signle device many times to create multiple file descriptors as
independent queues. User could also enable/disabe a specific queue through
TUNSETQUEUE.

The patch adds the generic infrastructure to create multiqueue taps. To achieve
this a new parameter "queues" were introduced to specify how many queues were
expected to be created for tap by qemu itself. Alternatively, management could
also pass multiple pre-created tap file descriptors separated with ':' through a
new parameter fds like -netdev tap,id=hn0,fds="X:Y:..:Z". Multiple vhost file
descriptors could also be passed in this way.

Each TAPState were still associated to a tap fd, which mean multiple TAPStates
were created when user needs multiqueue taps. Since each TAPState contains one
NetClientState, with the multiqueue nic support, an N peers of NetClientState
were built up.

A new parameter, mq_required were introduce in tap_open() to create multiqueue
tap fds.

Signed-off-by: Jason Wang <jasowang@redhat.com>
vhost: multiqueue support

This patch lets vhost support multiqueue. The idea is simple, just launching
multiple threads of vhost and let each of vhost thread processing a subset of
the virtqueues of the device. After this change each emulated device can have
multiple vhost threads as its backend.

To do this, a virtqueue index were introduced to record to first virtqueue that
will be handled by this vhost_net device. Based on this and nvqs, vhost could
calculate its relative index to setup vhost_net device.

Since we may have many vhost/net devices for a virtio-net device. The setting of
guest notifiers were moved out of the starting/stopping of a specific vhost
thread. The vhost_net_{start|stop}() were renamed to
vhost_net_{start|stop}_one(), and a new vhost_net_{start|stop}() were introduced
to configure the guest notifiers and start/stop all vhost/vhost_net devices.

Signed-off-by: Jason Wang <jasowang@redhat.com>
virtio: introduce virtio_del_queue()

Some device (such as virtio-net) needs the ability to destroy or re-order the
virtqueues, this patch adds a helper to do this.

Signed-off-by: Jason Wang <jasowang>
virtio: add a queue_index to VirtQueue

Add a queue_index to VirtQueue and a helper to fetch it, this could be used by
multiqueue supported device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
virtio-net: separate virtqueue from VirtIONet

To support multiqueue virtio-net, the first step is to separate the virtqueue
related fields from VirtIONet to a new structure VirtIONetQueue. The following
patches will add an array of VirtIONetQueue to VirtIONet based on this patch.

Signed-off-by: Jason Wang <jasowang@redhat.com>
virtio-net: multiqueue support

This patch implements both userspace and vhost support for multiple queue
virtio-net (VIRTIO_NET_F_MQ). This is done by introducing an array of
VirtIONetQueue to VirtIONet.

Signed-off-by: Jason Wang <jasowang@redhat.com>