Commit graph

24 commits

Author SHA1 Message Date
Jiri Pirko
be50da3e9d net: virtio_net: implement exact header length guest feature
Virtio spec introduced a feature VIRTIO_NET_F_GUEST_HDRLEN which when
set implicates that device benefits from knowing the exact size
of the header. For compatibility, to signal to the device that
the header is reliable driver also needs to set this feature.
Without this feature set by driver, device has to figure
out the header size itself.

Quoting the original virtio spec:
"hdr_len is a hint to the device as to how much of the header needs to
 be kept to copy into each packet"

"a hint" might not be clear for the reader what does it mean, if it is
"maybe like that" of "exactly like that". This feature just makes it
crystal clear and let the device count on the hdr_len being filled up
by the exact length of header.

Also note the spec already has following note about hdr_len:
"Due to various bugs in implementations, this field is not useful
 as a guarantee of the transport header size."

Without this feature the device needs to parse the header in core
data path handling. Accurate information helps the device to eliminate
such header parsing and directly use the hardware accelerators
for GSO operation.

virtio_net_hdr_from_skb() fills up hdr_len to skb_headlen(skb).
The driver already complies to fill the correct value. Introduce the
feature and advertise it.

Note that virtio spec also includes following note for device
implementation:
"Caution should be taken by the implementation so as to prevent
 a malicious driver from attacking the device by setting
 an incorrect hdr_len."

There is a plan to support this feature in our emulated device.
A device of SolidRun offers this feature bit. They claim this feature
will save the device a few cycles for every GSO packet.

Link: https://docs.oasis-open.org/virtio/virtio/v1.2/cs01/virtio-v1.2-cs01.html#x1-230006x3
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20230309094559.917857-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-13 16:32:16 -07:00
Andrew Melnychenko
34061b348a uapi/linux/virtio_net.h: Added USO types.
Added new GSO type for USO: VIRTIO_NET_HDR_GSO_UDP_L4.
Feature VIRTIO_NET_F_HOST_USO allows to enable NETIF_F_GSO_UDP_L4.
Separated VIRTIO_NET_F_GUEST_USO4 & VIRTIO_NET_F_GUEST_USO6 features
required for Windows guests.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-12-12 09:29:56 +00:00
Alvaro Karsz
fce1c23f62 net: virtio_net: fix notification coalescing comments
Fix wording in comments for the notifications coalescing feature.

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20220823073947.14774-1-alvaro.karsz@solid-run.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-30 22:44:25 -07:00
Alvaro Karsz
699b045a8e net: virtio_net: notifications coalescing support
New VirtIO network feature: VIRTIO_NET_F_NOTF_COAL.

Control a Virtio network device notifications coalescing parameters
using the control virtqueue.

A device that supports this fetature can receive
VIRTIO_NET_CTRL_NOTF_COAL control commands.

- VIRTIO_NET_CTRL_NOTF_COAL_TX_SET:
  Ask the network device to change the following parameters:
  - tx_usecs: Maximum number of usecs to delay a TX notification.
  - tx_max_packets: Maximum number of packets to send before a
    TX notification.

- VIRTIO_NET_CTRL_NOTF_COAL_RX_SET:
  Ask the network device to change the following parameters:
  - rx_usecs: Maximum number of usecs to delay a RX notification.
  - rx_max_packets: Maximum number of packets to receive before a
    RX notification.

VirtIO spec. patch:
https://lists.oasis-open.org/archives/virtio-comment/202206/msg00100.html

Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com>
Message-Id: <20220718091102.498774-1-alvaro.karsz@solid-run.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jason Wang <jasowang@redhat.com>
2022-08-11 04:26:07 -04:00
Michael S. Tsirkin
64ffa39dc8 virtio_net: use LE accessors for speed/duplex
Speed and duplex config fields depend on VIRTIO_NET_F_SPEED_DUPLEX
which being 63>31 depends on VIRTIO_F_VERSION_1.

Accordingly, use LE accessors for these fields.

Reported-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 11:08:41 -04:00
Michael S. Tsirkin
577e677a78 virtio_net: correct tags for config space fields
Tag config space fields as having virtio endian-ness.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05 11:08:40 -04:00
Yuri Benditovich
3024e20958 virtio-net: Introduce hash report feature
The feature VIRTIO_NET_F_HASH_REPORT extends the
layout of the packet and requests the device to
calculate hash on incoming packets and report it
in the packet header.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Link: https://lore.kernel.org/r/20200302115003.14877-4-yuri.benditovich@daynix.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-03-23 09:50:02 -04:00
Yuri Benditovich
fd58bf6745 virtio-net: Introduce RSS receive steering feature
RSS (Receive-side scaling) defines hash calculation
rules and decision on receive virtqueue according to
the calculated hash, provided mask to apply and
provided indirection table containing indices of
receive virqueues. The driver sends the control
command to enable multiqueue and provide parameters
for receive steering.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Link: https://lore.kernel.org/r/20200302115003.14877-3-yuri.benditovich@daynix.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-03-23 09:50:02 -04:00
Yuri Benditovich
22b436c9b5 virtio-net: Introduce extended RSC feature
VIRTIO_NET_F_RSC_EXT feature bit indicates that the device
is able to provide extended RSC information. When the feature
is negotiatede and 'gso_type' field in received packet is not
GSO_NONE, the device reports number of coalesced packets in
'csum_start' field and number of duplicated acks in 'csum_offset'
field and sets VIRTIO_NET_HDR_F_RSC_INFO in 'flags' field.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Link: https://lore.kernel.org/r/20200302115003.14877-2-yuri.benditovich@daynix.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-03-23 09:50:02 -04:00
Sridhar Samudrala
9805069d14 virtio_net: Introduce VIRTIO_NET_F_STANDBY feature bit
This feature bit can be used by hypervisor to indicate virtio_net device to
act as a standby for another device with the same MAC address.

VIRTIO_NET_F_STANDBY is defined as bit 62 as it is a device feature bit.

Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-28 22:59:54 -04:00
Jason Baron
faa9b39f0e virtio_net: propagate linkspeed/duplex settings from the hypervisor
The ability to set speed and duplex for virtio_net is useful in various
scenarios as described here:

16032be virtio_net: add ethtool support for set and get of settings

However, it would be nice to be able to set this from the hypervisor,
such that virtio_net doesn't require custom guest ethtool commands.

Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows
the hypervisor to export a linkspeed and duplex setting. The user can
subsequently overwrite it later if desired via: 'ethtool -s'.

Note that VIRTIO_NET_F_SPEED_DUPLEX is defined as bit 63, the intention
is that device feature bits are to grow down from bit 63, since the
transports are starting from bit 24 and growing up.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: virtio-dev@lists.oasis-open.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-09 11:37:56 -05:00
Mike Rapoport
678ece3022 virtio_net: add _UAPI prefix to virtio_net header guards
This gives better namespacing and prevents conflicts with no-uapi version
of virtio_net header that will be introduced in the following patch.

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10 23:03:55 -07:00
Aaron Conole
7d84e37e11 virtio_net: Update the feature bit to comply with spec
A draft version of the MTU Advice feature bit was specified as 25.  This
bit is not within the allowed range for network device feature bits, and
should be changed to be feature bit 3 to fully comply with the spec.

Fixes 14de9d114a ('virtio-net: Add initial MTU advice feature')
Signed-off-by: Aaron Conole <aconole@redhat.com>
Suggested-by: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-09 23:35:26 -07:00
Aaron Conole
14de9d114a virtio-net: Add initial MTU advice feature
This commit adds the feature bit and associated mtu device entry for the
virtio network device.  When a virtio device comes up, it checks the
feature bit for the VIRTIO_NET_F_MTU feature.  If such feature bit is
enabled, the driver will read the advised MTU and use it as the initial
value.

Signed-off-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-06 21:08:49 -04:00
Michael S. Tsirkin
8b0a9d4230 virtio_net: document VIRTIO_NET_CTRL_GUEST_OFFLOADS
Document VIRTIO_NET_CTRL_GUEST_OFFLOADS and the
relevant feature bits.

Will allow ethtool control of the offloads down the road.

Reported-by: Yan Vugenfirer <yan@daynix.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-07-01 10:11:17 +02:00
Rusty Russell
e68c48f975 virtio_net: unconditionally define struct virtio_net_hdr_v1.
This was introduced in commit ed9ecb0415,
but only defined if !VIRTIO_NET_NO_LEGACY.  We should always define
it: easier for users to have conditional legacy code.

Suggested-by: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-17 16:19:27 +10:30
Rusty Russell
ed9ecb0415 virtio: Don't expose legacy net features when VIRTIO_NET_NO_LEGACY defined.
In particular, the virtio header always has the u16 num_buffers field.
We define a new 'struct virtio_net_hdr_v1' for this (rather than
simply calling it 'struct virtio_net_hdr', to avoid nasty type errors
if some parts of a project define VIRTIO_NET_NO_LEGACY and some don't.

Transitional devices (which can't define VIRTIO_NET_NO_LEGACY) will
have to keep using struct virtio_net_hdr_mrg_rxbuf, which has the same
byte layout as struct virtio_net_hdr_v1.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-02-13 17:15:54 +10:30
Michael S. Tsirkin
fdd819b215 virtio_net: v1.0 endianness
Based on patches by Rusty Russell, Cornelia Huck.
Note: more code changes are needed for 1.0 support
(due to different header size).
So we don't advertize support for 1.0 yet.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-09 12:05:26 +02:00
Joe Perches
e216975ad9 uapi: Convert some uses of 6 to ETH_ALEN
Use the #define where appropriate.

Add #include <linux/if_ether.h>
where appropriate too.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-02 12:33:54 -07:00
Michael S. Tsirkin
e7428e95a0 virtio-net: put virtio net header inline with data
For small packets we can simplify xmit processing
by linearizing buffers with the header:
most packets seem to have enough head room
we can use for this purpose.
Since existing hypervisors require that header
is the first s/g element, we need a feature bit
for this.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-27 20:06:10 -07:00
stephen hemminger
77d21f23a1 virtio: don't expose u16 in userspace api
Programs using virtio headers outside of kernel will no longer
build because u16 type does not exist in userspace. All user ABI
must use __u16 typedef instead.

Bug introduce by:
  commit 986a4f4d45
  Author: Jason Wang <jasowang@redhat.com>
  Date:   Fri Dec 7 07:04:56 2012 +0000

    virtio_net: multiqueue support

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-05 16:58:01 -04:00
Amos Kong
7e58d5aea8 virtio-net: introduce a new control to set macaddr
Currently we write MAC address to pci config space byte by byte,
this means that we have an intermediate step where mac is wrong.
This patch introduced a new control command to set MAC address,
it's atomic.

VIRTIO_NET_F_CTRL_MAC_ADDR is a new feature bit for compatibility.

Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 14:07:44 -05:00
Jason Wang
986a4f4d45 virtio_net: multiqueue support
This patch adds the multiqueue (VIRTIO_NET_F_MQ) support to virtio_net
driver. VIRTIO_NET_F_MQ capable device could allow the driver to do packet
transmission and reception through multiple queue pairs and does the packet
steering to get better performance. By default, one one queue pair is used, user
could change the number of queue pairs by ethtool in the next patch.

When multiple queue pairs is used and the number of queue pairs is equal to the
number of vcpus. Driver does the following optimizations to implement per-cpu
virt queue pairs:

- select the txq based on the smp processor id.
- smp affinity hint to the cpu that owns the queue pairs.

This could be used with the flow steering support of the device to guarantee the
packets of a single flow is handled by the same cpu.

Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-09 00:30:55 -05:00
David Howells
607ca46e97 UAPI: (Scripted) Disintegrate include/linux
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-13 10:46:48 +01:00
Renamed from include/linux/virtio_net.h (Browse further)