free_unused_bufs must check vi->mergeable_rx_bufs before
vi->big_packets, because we use this sequence in other places.
Otherwise we allocate buffer of one type, then free it as another
type.

general protection fault: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in: ip6table_filter ip6_tables iptable_filter ip_tables pcspkr virtio_balloon virtio_net(-) i2c_pii
CPU: 0 PID: 400 Comm: rmmod Not tainted 3.13.0-rc2+ #170
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
task: ffff8800b6d2a210 ti: ffff8800aed32000 task.ti: ffff8800aed32000
RIP: 0010:[<ffffffffa00345f3>]  [<ffffffffa00345f3>] free_unused_bufs+0xc3/0x190 [virtio_net]
RSP: 0018:ffff8800aed33dd8  EFLAGS: 00010202
RAX: ffff8800b1fe2c00 RBX: ffff8800b66a7240 RCX: 6b6b6b6b6b6b6b6b
RDX: 6b6b6b6b6b6b6b6b RSI: ffff8800b8419a68 RDI: ffff8800b66a1148
RBP: ffff8800aed33e00 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: ffff8800b66a1148 R14: 0000000000000000 R15: 000077ff80000000
FS:  00007fc4f9c4e740(0000) GS:ffff8800bfa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f63f432f000 CR3: 00000000b6538000 CR4: 00000000000006f0
Stack:
 ffff8800b66a7240 ffff8800b66a7380 ffff8800377bd3f0 0000000000000000
 00000000023302f0 ffff8800aed33e18 ffffffffa00346e2 ffff8800b66a7240
 ffff8800aed33e38 ffffffffa003474d ffff8800377bd388 ffff8800377bd390
Call Trace:
 [<ffffffffa00346e2>] remove_vq_common+0x22/0x40 [virtio_net]
 [<ffffffffa003474d>] virtnet_remove+0x4d/0x90 [virtio_net]
 [<ffffffff813ae303>] virtio_dev_remove+0x23/0x80
 [<ffffffff813f62cf>] __device_release_driver+0x7f/0xf0
 [<ffffffff813f6c80>] driver_detach+0xc0/0xd0
 [<ffffffff813f5f08>] bus_remove_driver+0x58/0xd0
 [<ffffffff813f72cc>] driver_unregister+0x2c/0x50
 [<ffffffff813ae63e>] unregister_virtio_driver+0xe/0x10
 [<ffffffffa0036852>] virtio_net_driver_exit+0x10/0x7be [virtio_net]
 [<ffffffff810d7cf2>] SyS_delete_module+0x172/0x220
 [<ffffffff810a732d>] ? trace_hardirqs_on+0xd/0x10
 [<ffffffff810f5d4c>] ? __audit_syscall_entry+0x9c/0xf0
 [<ffffffff81677f69>] system_call_fastpath+0x16/0x1b
Code: c0 74 55 0f 1f 44 00 00 80 7b 30 00 74 7a 48 8b 50 30 4c 89 e6 48 03 73 20 48 85 d2 0f 84 bb 00 00 00 66 0f
RIP  [<ffffffffa00345f3>] free_unused_bufs+0xc3/0x190 [virtio_net]
 RSP <ffff8800aed33dd8>
---[ end trace edb570ea923cce9c ]---

Fixes: 2613af0e (virtio_net: migrate mergeable rx buffers to page frag allocators)
Cc: Michael Dalton <mwdalton@google.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: NAndrey Vagin <avagin@openvz.org>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

receive mergeable now handles errors internally.
Do same for big and small packet paths, otherwise
the logic is too hard to follow.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Eric Dumazet noticed that if we encounter an error
when processing a mergeable buffer, we don't
dequeue all of the buffers from this packet,
the result is almost sure to be loss of networking.

Jason Wang noticed that we also leak a page and that we don't decrement
the rq buf count, so we won't repost buffers (a resource leak).

Fix both issues.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael Dalton <mwdalton@google.com>
Reported-by: NEric Dumazet <edumazet@google.com>
Reported-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

"MAC filter" sounds more reasonable than "MAC fitler".
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is more appropriate to use # of queue pairs currently used by
the driver instead of a magic value.
Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 2613af0e ("virtio_net: migrate mergeable rx buffers to page
frag allocators") changed the mergeable receive buffer size from PAGE_SIZE
to MTU-size. However, the merge buffer size does not take into account the
size of the virtio-net header. Consequently, packets that are MTU-size
will take two buffers intead of one (to store the virtio-net header),
substantially decreasing the throughput of MTU-size traffic due to TCP
window / SKB truesize effects.

This commit changes the mergeable buffer size to include the virtio-net
header. The buffer size is cacheline-aligned because skb_page_frag_refill
will not automatically align the requested size.

Benchmarks taken from an average of 5 netperf 30-second TCP_STREAM runs
between two QEMU VMs on a single physical machine. Each VM has two VCPUs and
vhost enabled. All VMs and vhost threads run in a single 4 CPU cgroup
cpuset, using cgroups to ensure that other processes in the system will not
be scheduled on the benchmark CPUs. Transmit offloads and mergeable receive
buffers are enabled, but guest_tso4 / guest_csum are explicitly disabled to
force MTU-sized packets on the receiver.

next-net trunk before 2613af0e (PAGE_SIZE buf): 3861.08Gb/s
net-next trunk (MTU 1500- packet uses two buf due to size bug): 4076.62Gb/s
net-next trunk (MTU 1480- packet fits in one buf): 6301.34Gb/s
net-next trunk w/ size fix (MTU 1500 - packet fits in one buf): 6445.44Gb/s
Suggested-by: NEric Northup <digitaleric@google.com>
Signed-off-by: NMichael Dalton <mwdalton@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to enable lockdep on seqcount/seqlock structures, we
must explicitly initialize any locks.

The u64_stats_sync structure, uses a seqcount, and thus we need
to introduce a u64_stats_init() function and use it to initialize
the structure.

This unfortunately adds a lot of fairly trivial initialization code
to a number of drivers. But the benefit of ensuring correctness makes
this worth while.

Because these changes are required for lockdep to be enabled, and the
changes are quite trivial, I've not yet split this patch out into 30-some
separate patches, as I figured it would be better to get the various
maintainers thoughts on how to best merge this change along with
the seqcount lockdep enablement.

Feedback would be appreciated!
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Acked-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: James Morris <jmorris@namei.org>
Cc: Jesse Gross <jesse@nicira.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mirko Lindner <mlindner@marvell.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Roger Luethi <rl@hellgate.ch>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Simon Horman <horms@verge.net.au>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Wensong Zhang <wensong@linux-vs.org>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-2-git-send-email-john.stultz@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

We used to use a percpu structure vq_index to record the cpu to queue
mapping, this is suboptimal since it duplicates the work of XPS and
loses all other XPS functionality such as allowing user to configure
their own transmission steering strategy.

So this patch switches to use XPS and suggest a default mapping when
the number of cpus is equal to the number of queues. With XPS support,
there's no need for keeping per-cpu vq_index and .ndo_select_queue(),
so they were removed also.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 2613af0e (virtio_net: migrate mergeable
rx buffers to page frag allocators) try to increase the payload/truesize for
MTU-sized traffic. But this will introduce the extra overhead for GSO packets
received because of the frag list. This commit tries to reduce this issue by
coalesce the possible rx frags when possible during rx. Test result shows the
about 15% improvement on full size GSO packet receiving (and even better than
before commit 2613af0e).

Before this commit:
./netperf -H 192.168.100.4
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.100.4
() port 0 AF_INET : demo
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    20303.87

After this commit:
./netperf -H 192.168.100.4
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.100.4
() port 0 AF_INET : demo
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    23841.26

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Michael Dalton <mwdalton@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 3ab098df (virtio-net: don't respond to
cpu hotplug notifier if we're not ready) tries to bypass the cpu hotplug
notifier by checking the config_enable and does nothing is it was false. So it
need to try to hold the config_lock mutex which may happen in atomic
environment which leads the following warnings:

[  622.944441] CPU0 attaching NULL sched-domain.
[  622.944446] CPU1 attaching NULL sched-domain.
[  622.944485] CPU0 attaching NULL sched-domain.
[  622.950795] BUG: sleeping function called from invalid context at kernel/mutex.c:616
[  622.950796] in_atomic(): 1, irqs_disabled(): 1, pid: 10, name: migration/1
[  622.950796] no locks held by migration/1/10.
[  622.950798] CPU: 1 PID: 10 Comm: migration/1 Not tainted 3.12.0-rc5-wl-01249-gb91e82d #317
[  622.950799] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  622.950802]  0000000000000000 ffff88001d42dba0 ffffffff81a32f22 ffff88001bfb9c70
[  622.950803]  ffff88001d42dbb0 ffffffff810edb02 ffff88001d42dc38 ffffffff81a396ed
[  622.950805]  0000000000000046 ffff88001d42dbe8 ffffffff810e861d 0000000000000000
[  622.950805] Call Trace:
[  622.950810]  [<ffffffff81a32f22>] dump_stack+0x54/0x74
[  622.950815]  [<ffffffff810edb02>] __might_sleep+0x112/0x114
[  622.950817]  [<ffffffff81a396ed>] mutex_lock_nested+0x3c/0x3c6
[  622.950818]  [<ffffffff810e861d>] ? up+0x39/0x3e
[  622.950821]  [<ffffffff8153ea7c>] ? acpi_os_signal_semaphore+0x21/0x2d
[  622.950824]  [<ffffffff81565ed1>] ? acpi_ut_release_mutex+0x5e/0x62
[  622.950828]  [<ffffffff816d04ec>] virtnet_cpu_callback+0x33/0x87
[  622.950830]  [<ffffffff81a42576>] notifier_call_chain+0x3c/0x5e
[  622.950832]  [<ffffffff810e86a8>] __raw_notifier_call_chain+0xe/0x10
[  622.950835]  [<ffffffff810c5556>] __cpu_notify+0x20/0x37
[  622.950836]  [<ffffffff810c5580>] cpu_notify+0x13/0x15
[  622.950838]  [<ffffffff81a237cd>] take_cpu_down+0x27/0x3a
[  622.950841]  [<ffffffff81136289>] stop_machine_cpu_stop+0x93/0xf1
[  622.950842]  [<ffffffff81136167>] cpu_stopper_thread+0xa0/0x12f
[  622.950844]  [<ffffffff811361f6>] ? cpu_stopper_thread+0x12f/0x12f
[  622.950847]  [<ffffffff81119710>] ? lock_release_holdtime.part.7+0xa3/0xa8
[  622.950848]  [<ffffffff81135e4b>] ? cpu_stop_should_run+0x3f/0x47
[  622.950850]  [<ffffffff810ea9b0>] smpboot_thread_fn+0x1c5/0x1e3
[  622.950852]  [<ffffffff810ea7eb>] ? lg_global_unlock+0x67/0x67
[  622.950854]  [<ffffffff810e36b7>] kthread+0xd8/0xe0
[  622.950857]  [<ffffffff81a3bfad>] ? wait_for_common+0x12f/0x164
[  622.950859]  [<ffffffff810e35df>] ? kthread_create_on_node+0x124/0x124
[  622.950861]  [<ffffffff81a45ffc>] ret_from_fork+0x7c/0xb0
[  622.950862]  [<ffffffff810e35df>] ? kthread_create_on_node+0x124/0x124
[  622.950876] smpboot: CPU 1 is now offline
[  623.194556] SMP alternatives: lockdep: fixing up alternatives
[  623.194559] smpboot: Booting Node 0 Processor 1 APIC 0x1
...

A correct fix is to unregister the hotcpu notifier during restore and register a
new one in resume.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Tested-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The virtio_net driver's mergeable receive buffer allocator
uses 4KB packet buffers. For MTU-sized traffic, SKB truesize
is > 4KB but only ~1500 bytes of the buffer is used to store
packet data, reducing the effective TCP window size
substantially. This patch addresses the performance concerns
with mergeable receive buffers by allocating MTU-sized packet
buffers using page frag allocators. If more than MAX_SKB_FRAGS
buffers are needed, the SKB frag_list is used.
Signed-off-by: NMichael Dalton <mwdalton@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a virtqueue_get_buf() call returns a NULL pointer a possibly endless while
loop should be avoided by checking for a broken virtqueue.
Signed-off-by: NHeinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Verify if a host kick succeeded by checking return value of virtqueue_kick().
Signed-off-by: NHeinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

We used to schedule the refill work unconditionally after changing the
number of queues. This may lead an issue if the device is not
up. Since we only try to cancel the work in ndo_stop(), this may cause
the refill work still work after removing the device. Fix this by only
schedule the work when device is up.

The bug were introduce by commit 9b9cd802.
(virtio-net: fix the race between channels setting and refill)

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're trying to re-configure the affinity unconditionally in cpu hotplug
callback. This may lead the issue during resuming from s3/s4 since

- virt queues haven't been allocated at that time.
- it's unnecessary since thaw method will re-configure the affinity.

Fix this issue by checking the config_enable and do nothing is we're not ready.

The bug were introduced by commit 8de4b2f3
(virtio-net: reset virtqueue affinity when doing cpu hotplug).

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This lets the transport do endian conversion if necessary, and insulates
the drivers from the difference.

Most drivers can use the simple helpers virtio_cread() and virtio_cwrite().
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The freeze and restore functions defined in virtio drivers are used
for suspend and hibernate, so CONFIG_PM_SLEEP is more appropriate than
CONFIG_PM. This patch replace all CONFIG_PM with CONFIG_PM_SLEEP for
virtio drivers that implement freeze and restore callbacks.
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

If the VIRTIO_NET_F_GUEST_CSUM virtio feature is available, the guest
does not have to calculate the checksums on all received packets. This
is pretty much the same feature as RX checksum offloading on real
network cards, so the virtio-net driver should report this by setting
the NETIF_F_RXCSUM flag. When the user now runs "ethtool -k", he or she
can see whether the virtio-net interface has to calculate RX checksums
or not.
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

virtio net called virtqueue_enable_cq on RX path after napi_complete, so
with NAPI_STATE_SCHED clear - outside the implicit napi lock.
This violates the requirement to synchronize virtqueue_enable_cq wrt
virtqueue_add_buf.  In particular, used event can move backwards,
causing us to lose interrupts.
In a debug build, this can trigger panic within START_USE.

Jason Wang reports that he can trigger the races artificially,
by adding udelay() in virtqueue_enable_cb() after virtio_mb().

However, we must call napi_complete to clear NAPI_STATE_SCHED before
polling the virtqueue for used buffers, otherwise napi_schedule_prep in
a callback will fail, causing us to lose RX events.

To fix, call virtqueue_enable_cb_prepare with NAPI_STATE_SCHED
set (under napi lock), later call virtqueue_poll with
NAPI_STATE_SCHED clear (outside the lock).
Reported-by: NJason Wang <jasowang@redhat.com>
Tested-by: NJason Wang <jasowang@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 55257d72 (virtio-net: fill only rx queues
which are being used) tries to refill on demand when changing the number of
channels by call try_refill_recv() directly, this may race:

- the refill work who may do the refill in the same time
- the try_refill_recv() called in bh since napi was not disabled

Which may led guest complain during setting channels:

virtio_net virtio0: input.1:id 0 is not a head!

Solve this issue by scheduling a refill work which can guarantee the
serialization of refill.

Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Commit 55257d72 (virtio-net: fill only rx
queues which are being used) only does the napi enabling during open for
curr_queue_pairs. This will break multiqueue receiving since napi of new queues
were still disabled after changing the number of queues.

This patch fixes this by enabling napi for all possible queues during open.

Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 82dc3c63 ("net: introduce NAPI_POLL_WEIGHT")
we warn drivers when they use napi weight higher than NAPI_POLL_WEIGHT,
but virtio_net still uses 128 by default. This patch makes its default
value to NAPI_POLL_WEIGHT.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to MQ support we may allocate a whole bunch of rx queues but
never use them. With this patch we'll safe the space used by
the receive buffers until they are actually in use:

sh-4.2# free -h
             total       used       free     shared    buffers     cached
Mem:          490M        35M       455M         0B         0B       4.1M
-/+ buffers/cache:        31M       459M
Swap:           0B         0B         0B
sh-4.2# ethtool -L eth0 combined 8
sh-4.2# free -h
             total       used       free     shared    buffers     cached
Mem:          490M       162M       327M         0B         0B       4.1M
-/+ buffers/cache:       158M       331M
Swap:           0B         0B         0B
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Change the rx_{add,kill}_vid callbacks to take a protocol argument in
preparation of 802.1ad support. The protocol argument used so far is
always htons(ETH_P_8021Q).
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename the hardware VLAN acceleration features to include "CTAG" to indicate
that they only support CTAGs. Follow up patches will introduce 802.1ad
server provider tagging (STAGs) and require the distinction for hardware not
supporting acclerating both.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There's nothing that prevent passing the device features of virtio_net to its
vlan device. So this patch simply passes those to vlan device to benefit from
advanced features.

Netperf shows better sending performance for vlan device since TSO can work on
vlan now.

before:
netperf -H 192.168.5.2
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.5.2 ()
port 0 AF_INET : demo
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    4162.35

after:
netperf -H 192.168.5.2
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.5.2 ()
port 0 AF_INET : demo
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    9365.42

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

You can access it directly now, since 3.8: v3.7-rc1-13-g06ca287d
'virtio: move queue_index and num_free fields into core struct
virtqueue.'

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We never add buffers with input and output parts, so use the new accessors.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Reviewed-by: NAsias He <asias@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

It's a bit cleaner to hand multiple sgs, rather than one big one.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Tested-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Patch cef401de (net: fix possible wrong checksum
generation) fixed wrong checksum calculation but it broke TSO by
defining new GSO type but not a netdev feature for that type.
net_gso_ok() would not allow hardware checksum/segmentation
offload of such packets without the feature.

Following patch fixes TSO and wrong checksum. This patch uses
same logic that Eric Dumazet used. Patch introduces new flag
SKBTX_SHARED_FRAG if at least one frag can be modified by
the user. but SKBTX_SHARED_FRAG flag is kept in skb shared
info tx_flags rather than gso_type.

tx_flags is better compared to gso_type since we can have skb with
shared frag without gso packet. It does not link SHARED_FRAG to
GSO, So there is no need to define netdev feature for this.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

alloc failures already get standardized OOM
messages and a dump_stack.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pravin Shelar mentioned that GSO could potentially generate
wrong TX checksum if skb has fragments that are overwritten
by the user between the checksum computation and transmit.

He suggested to linearize skbs but this extra copy can be
avoided for normal tcp skbs cooked by tcp_sendmsg().

This patch introduces a new SKB_GSO_SHARED_FRAG flag, set
in skb_shinfo(skb)->gso_type if at least one frag can be
modified by the user.

Typical sources of such possible overwrites are {vm}splice(),
sendfile(), and macvtap/tun/virtio_net drivers.

Tested:

$ netperf -H 7.7.8.84
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
7.7.8.84 () port 0 AF_INET
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    3959.52

$ netperf -H 7.7.8.84 -t TCP_SENDFILE
TCP SENDFILE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 7.7.8.84 ()
port 0 AF_INET
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 87380  16384  16384    10.00    3216.80

Performance of the SENDFILE is impacted by the extra allocation and
copy, and because we use order-0 pages, while the TCP_STREAM uses
bigger pages.
Reported-by: NPravin Shelar <pshelar@nicira.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a cpu notifier to virtio-net, so that we can reset the
virtqueue affinity if the cpu hotplug happens. It improve
the performance through enabling or disabling the virtqueue
affinity after doing cpu hotplug.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Eric Dumazet <erdnetdev@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: virtualization@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Signed-off-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Split out the clean affinity function to virtnet_clean_affinity().

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Eric Dumazet <erdnetdev@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: virtualization@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Signed-off-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As Michael mentioned, set affinity and select queue will not work very
well when CPU IDs are not consecutive, this can happen with hot unplug.
Fix this bug by traversal the online CPUs, and create a per cpu variable
to find the mapping from CPU to the preferable virtual-queue.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Eric Dumazet <erdnetdev@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: virtualization@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Signed-off-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NAmos Kong <akong@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We want to send vq command to set mac address in
virtnet_set_mac_address(), so do this function moving.
Fixed a little issue of coding style.
Signed-off-by: NAmos Kong <akong@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We simplified virtqueue_add_buf(), make it clear in the callers.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>