We don't put page during linearizing, the would cause leaking when
xmit through XDP_TX or the packet exceeds PAGE_SIZE. Fix them by
put page accordingly. Also decrease the number of buffers during
linearizing to make sure caller can free buffers correctly when packet
exceeds PAGE_SIZE. With this patch, we won't get OOM after linearize
huge number of packets.
Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After we linearize page, we should xmit this page instead of the page
of first buffer which may lead unexpected result. With this patch, we
can see correct packet during XDP_TX.
Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since we use EWMA to estimate the size of rx buffer. When rx buffer
size is underestimated, it's usual to have a packet with more than one
buffers. Consider this is not a bug, remove the warning and correct
the comment before XDP linearizing.
Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
virtio_net XDP support expects receive buffers to be contiguous.
If this is not the case we enable a slowpath to allow connectivity
to continue but at a significan performance overhead associated with
linearizing data. To make it painfully aware to users that XDP is
running in a degraded mode we throw an xdp buffer error.
To linearize packets we allocate a page and copy the segments of
the data, including the header, into it. After this the page can be
handled by XDP code flow as normal.
Then depending on the return code the page is either freed or sent
to the XDP xmit path. There is no attempt to optimize this path.
This case is being handled simple as a precaution in case some
unknown backend were to generate packets in this form. To test this
I had to hack qemu and force it to generate these packets. I do not
expect this case to be generated by "real" backends.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds support for the XDP_TX action to virtio_net. When an XDP
program is run and returns the XDP_TX action the virtio_net XDP
implementation will transmit the packet on a TX queue that aligns
with the current CPU that the XDP packet was processed on.
Before sending the packet the header is zeroed. Also XDP is expected
to handle checksum correctly so no checksum offload support is
provided.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
XDP requires using isolated transmit queues to avoid interference
with normal networking stack (BQL, NETDEV_TX_BUSY, etc). This patch
adds a XDP queue per cpu when a XDP program is loaded and does not
expose the queues to the OS via the normal API call to
netif_set_real_num_tx_queues(). This way the stack will never push
an skb to these queues.
However virtio/vhost/qemu implementation only allows for creating
TX/RX queue pairs at this time so creating only TX queues was not
possible. And because the associated RX queues are being created I
went ahead and exposed these to the stack and let the backend use
them. This creates more RX queues visible to the network stack than
TX queues which is worth mentioning but does not cause any issues as
far as I can tell.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds XDP support to virtio_net. Some requirements must be
met for XDP to be enabled depending on the mode. First it will
only be supported with LRO disabled so that data is not pushed
across multiple buffers. Second the MTU must be less than a page
size to avoid having to handle XDP across multiple pages.
If mergeable receive is enabled this patch only supports the case
where header and data are in the same buf which we can check when
a packet is received by looking at num_buf. If the num_buf is
greater than 1 and a XDP program is loaded the packet is dropped
and a warning is thrown. When any_header_sg is set this does not
happen and both header and data is put in a single buffer as expected
so we check this when XDP programs are loaded. Subsequent patches
will process the packet in a degraded mode to ensure connectivity
and correctness is not lost even if backend pushes packets into
multiple buffers.
If big packets mode is enabled and MTU/LRO conditions above are
met then XDP is allowed.
This patch was tested with qemu with vhost=on and vhost=off where
mergeable and big_packet modes were forced via hard coding feature
negotiation. Multiple buffers per packet was forced via a small
test patch to vhost.c in the vhost=on qemu mode.
Suggested-by: Shrijeet Mukherjee <shrijeet@gmail.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 4490001029 ("virtio-net: enable
multiqueue by default") blindly set the affinity instead of queues
during probe which can cause a mismatch of #queues between guest and
host. This patch fixes it by setting queues.
Reported-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Theodore Ts'o <tytso@mit.edu>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Fixes: 49000102901 ("virtio-net: enable multiqueue by default")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We use single queue even if multiqueue is enabled and let admin to
enable it through ethtool later. This is used to avoid possible
regression (small packet TCP stream transmission). But looks like an
overkill since:
- single queue user can disable multiqueue when launching qemu
- brings extra troubles for the management since it needs extra admin
tool in guest to enable multiqueue
- multiqueue performs much better than single queue in most of the
cases
So this patch enables multiqueue by default: if #queues is less than or
equal to #vcpu, enable as much as queue pairs; if #queues is greater
than #vcpu, enable #vcpu queue pairs.
Cc: Hannes Frederic Sowa <hannes@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Neil Horman <nhorman@redhat.com>
Cc: Jeremy Eder <jeder@redhat.com>
Cc: Marko Myllynen <myllynen@redhat.com>
Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All conflicts were simple overlapping changes except perhaps
for the Thunder driver.
That driver has a change_mtu method explicitly for sending
a message to the hardware. If that fails it returns an
error.
Normally a driver doesn't need an ndo_change_mtu method becuase those
are usually just range changes, which are now handled generically.
But since this extra operation is needed in the Thunder driver, it has
to stay.
However, if the message send fails we have to restore the original
MTU before the change because the entire call chain expects that if
an error is thrown by ndo_change_mtu then the MTU did not change.
Therefore code is added to nicvf_change_mtu to remember the original
MTU, and to restore it upon nicvf_update_hw_max_frs() failue.
Signed-off-by: David S. Miller <davem@davemloft.net>
It seems many drivers do not respect napi_hash_del() contract.
When napi_hash_del() is used before netif_napi_del(), an RCU grace
period is needed before freeing NAPI object.
Fixes: 91815639d8 ("virtio-net: rx busy polling support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Virtio 1.0 spec says VIRTIO_F_ANY_LAYOUT and VIRTIO_NET_F_GSO are
legacy-only feature bits. Do not negotiate them in virtio 1 mode. Note
this is a spec violation so we need to backport it to stable/downstream
kernels.
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The virtio committee recently ratified a change, VIRTIO-152, which
defines the mtu field to be 'max' MTU, not simply desired MTU.
This commit brings the virtio-net device in compliance with VIRTIO-152.
Additionally, drop the max_mtu branch - it cannot be taken since the u16
returned by virtio_cread16 will never exceed the initial value of
max_mtu.
Signed-off-by: Aaron Conole <aconole@redhat.com>
Acked-by: "Michael S. Tsirkin" <mst@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The commit e858fae2b0 ("virtio_net: use common code for virtio_net_hdr
and skb GSO conversion") replaced the tun code for header manipulation
with the generic helpers. While doing so, it implictly moved the
skb_partial_csum_set() invocation after eth_type_trans(), which
invalidate the current gso start/offset values.
Fix it by moving the helper invocation before the mac pulling.
Fixes: e858fae2b0 ("virtio_net: use common code for virtio_net_hdr and
skb GSO conversion")
Reported-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace open coded conversion between virtio_net_hdr to skb GSO info with
virtio_net_hdr_{from,to}_skb
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
In function virtnet_open() and virtnet_probe(), func try_fill_recv() may
be executed at the same time. VQ in virtqueue_add() has not been protected
well and BUG_ON will be triggered when virito_net.ko being removed.
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull virtio/vhost updates from Michael Tsirkin:
"New features, performance improvements, cleanups:
- basic polling support for vhost
- rework virtio to optionally use DMA API, fixing it on Xen
- balloon stats gained a new entry
- using the new napi_alloc_skb speeds up virtio net
- virtio blk stats can now be read while another VCPU is busy
inflating or deflating the balloon
plus misc cleanups in various places"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
virtio_net: replace netdev_alloc_skb_ip_align() with napi_alloc_skb()
vhost_net: basic polling support
vhost: introduce vhost_vq_avail_empty()
vhost: introduce vhost_has_work()
virtio_balloon: Allow to resize and update the balloon stats in parallel
virtio_balloon: Use a workqueue instead of "vballoon" kthread
virtio/s390: size of SET_IND payload
virtio/s390: use dev_to_virtio
vhost: rename vhost_init_used()
vhost: rename cross-endian helpers
virtio_blk: VIRTIO_BLK_F_WCE->VIRTIO_BLK_F_FLUSH
vring: Use the DMA API on Xen
virtio_pci: Use the DMA API if enabled
virtio_mmio: Use the DMA API if enabled
virtio: Add improved queue allocation API
virtio_ring: Support DMA APIs
vring: Introduce vring_use_dma_api()
s390/dma: Allow per device dma ops
alpha/dma: use common noop dma ops
dma: Provide simple noop dma ops
This gives small but noticeable rx performance improvement (2-3%)
and will allow exploiting future napi improvement.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Jason Wang
John Fastabend
David S. Miller
Andy Lutomirski
Eric Dumazet
Michael S. Tsirkin
Aaron Conole
Jarod Wilson
Sebastian Andrzej Siewior
Mike Rapoport
wangyunjian
Linus Torvalds
Paolo Abeni