After r360820, additional parameters are passed through the argument 'opts', and the name of the backend through the argument 'devname'. So, there is no need to skip the backend name from the 'opts' argument.
The backend uses the socket API with the PF_NETGRAPH protocol family, which is provided by the ng_socket(4).
To use the new backend, provide the following bhyve option:
-s X:Y:Z,[virtio-net|e1000],netgraph,socket=[ng_socket name],path=[destination node],hook=[our socket src hook],peerhook=[dst node hook]
Reviewed by: vmaffione, lutz_donnerhacke.de
Approved by: vmaffione (mentor)
Sponsored by: vstack.com
Differential Revision: https://reviews.freebsd.org/D24620
This patch adds a new netbe_peek_recvlen() function to the net
backend API. The new function allows the virtio-net receive code
to know in advance how many virtio descriptors chains will be
needed to receive the next packet. As a result, the implementation
of the virtio-net mergeable rx buffers feature becomes efficient,
so that we can enable it also with the tap(4) backend. For the
tap(4) backend, a bounce buffer is introduced to implement the
peeck_recvlen() callback, which implies an additional packet copy
on the receive datapath. In the future, it should be possible to
remove the bounce buffer (and so the additional copy), by
obtaining the length of the next packet from kevent data.
Reviewed by: grehan, aleksandr.fedorov@itglobal.com
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23472
This patch cleans up the API between the net frontends (e1000,
virtio-net) and the net backends (tap and netmap).
We move the virtio-net header stripping/prepending to the
virtio-net code, where this functionality belongs.
In this way, the netbe_send() and netbe_recv() signatures
can have const struct iov * rather than struct iov *.
Reviewed by: grehan, bcr, aleksandr.fedorov@itglobal.com
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D23342
Add printf() wrapper to use CR/CRLF terminators depending on whether
stdio is mapped to a tty open in raw mode.
Try to use the wrapper everywhere.
For now we leave the custom DPRINTF/WPRINTF defined by device
models, but we may remove them in the future.
Reviewed by: grehan, jhb
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D22657
Some of the printf statements only use LF to get a newline. However, a CR character is also required for the serial console to print debug logs in a nice way.
Fix those code locations that only use LF, by adding a CR character.
Reviewed by: markj, aleksandr.fedorov@itglobal.com
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D22552
Mergeable rx buffers is a virtio-net feature that allows the hypervisor
to use multiple RX descriptor chains to receive a single receive packet.
Without this feature, a TSO-enabled guest is compelled to publish only
64K (or 32K) long chains, and each of these large buffers is consumed
to receive a single packet, even a very short one. This is a waste of
memory, as a RX queue has room for 256 chains, which means up to 16MB
of buffer memory for each (single-queue) vtnet device.
With the feature on, the guest can publish 2K long chains, and the
hypervisor will merge them as needed.
This change also enables the feature in the netmap backend, which
supports virtio-net offloads. We plan to add support for the
tap backend too.
Note that differently from QEMU/KVM, here we implement one-copy receive,
while QEMU uses two copies.
Reviewed by: jhb
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D21007
If a VM is flooded with more ingress packets than the guest OS
can handle, the current virtio-net code will keep reading those
packets and drop most of them as no space is available in the
receive queue. This is an undesirable receive livelock, which
is a waste of CPU and memory resources and potentially opens to
DoS attacks.
With this change, virtio-net uses the new netbe_rx_disable()
function to disable ingress operation in the backend while the
guest is short on RX buffers. Once the guest makes more buffers
available to the RX virtqueue, ingress operation is enabled again
by calling netbe_rx_enable().
Reviewed by: bryanv, jhb
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20987
Extend the net backend interface with two functions, namely netbe_rx_disable()
and netbe_rx_enable(), which can be used by the net device emulators to stop
the backend from invoking the receive callback. This is useful for device
emulators, i.e., on hardware resets or to implement receive backpressure.
The mevent module has been extendede to support the addition of a disabled
event. To prevent race conditions, the net backends will start with receive
operation disabled. A follow-up patch will use the new functionalities in
the virtio-net device.
Reviewed by: jhb, markj
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D20973
Bhyve can currently emulate two virtual NICs, namely virtio-net and e1000,
and connect to the host network through two backends, namely tap and netmap.
However, there is no interface between virtual NIC functionalities and
backend functionalities. As a result, the backend code is duplicated between
the two virtual NIC implementations and also within the same virtual NIC.
Also, e1000 cannot currently use netmap as a backend.
This patch introduces a network backend API between virtio-net/e1000 and
tap/netmap, to improve code reuse and add missing functionalities.
Virtual NICs and backends can negotiate virtio-net features, such as checksum
offload and TSO. If the backend supports the features, it will propagate this
information to the guest, so that the latter can make use of them. Currently,
only netmap VALE ports support the features, but support should be added to
tap in the future.
Reviewed by: jhb, bryanv
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20659
