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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This patch change all info call back function to take
additional QDict * parameter, which allow those command
take parameter. Now it is set to NULL at default case.
Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Move public headers to include/net, and leave private headers in net/.
Put the virtio headers in include/net/tap.h, removing the multiple copies
that existed. Leave include/net/tap.h as the interface for NICs, and
net/tap_int.h as the interface for OS-specific parts of the tap backend.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Jason Wang
Wenchao Xia
Paolo Bonzini