Now we have a virtio detach API (in commit
f9bfbebf), we don't need to track xmit
skbs in the virio_net driver, which improves transmission performance.
Signed-off-by: NShirley Ma <xma@us.ibm.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>

This patch replaces dev->mc_count in all drivers (hopefully I didn't miss
anything). Used spatch and did small tweaks and conding style changes when
it was suitable.

Jirka
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

virtio_net receives packets from its pre-allocated vring buffers, then it
delivers these packets to upper layer protocols as skb buffs. So it's not
necessary to pre-allocate skb for each mergable buffer, then frees extra
skbs when buffers are merged into a large packet. This patch has deferred
skb allocation in receiving packets for both big packets and mergeable buffers
to reduce skb pre-allocations and skb frees. It frees unused buffers by calling
detach_unused_buf in vring, so recv skb queue is not needed.
Signed-off-by: NShirley Ma <xma@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I have seen RX stalls on a machine that experienced a suspected
OOM.  After the stall, the RX buffer is empty on the guest side
and there are exactly 16 entries available on the host side.  As
the number of entries is less than that required by a maximal
skb, the host cannot proceed.

The guest did not have a refill job scheduled.

My diagnosis is that an OOM had occured, with the delayed refill
job scheduled.  The job was able to allocate at least one skb, but
not enough to overcome the minimum required by the host to proceed.

As the refill job would only reschedule itself if it failed completely
to allocate any skbs, this would lead to an RX stall.

The following patch removes this stall possibility by always
rescheduling the refill job until the ring is totally refilled.

Testing has shown that the RX stall no longer occurs whereas
previously it would occur within a day.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces three macros to work with uc list from net drivers.
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Only files where David Miller is the primary git-signer.
wireless, wimax, ixgbe, etc are not modified.

Compile tested x86 allyesconfig only
Not all files compiled (not x86 compatible)

Added a few > 80 column lines, which I ignored.
Existing checkpatch complaints ignored.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit

	3d1285be (move virtnet_remove to .devexit.text)

introduced the first reference to __devexit in struct virtio_driver
virtio_net which upset modpost ("Section mismatch in reference from the
variable virtio_net to the function .devexit.text:virtnet_remove()").

Fix this by renaming virtio_net to virtio_net_driver.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reported-by: NMichael S. Tsirkin <mst@redhat.com>
Blame-taken-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

virtio net used to unlink skbs from send queues on error,
but ever since 48925e37
we do not do this. This causes guest data corruption and crashes
with vhost since net core can requeue the skb or free it without
it being taken off the list.

This patch fixes this by queueing the skb after successful
transmit.
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>

Rusty,

commit 3ca4f5ca
    virtio: add virtio IDs file
moved all device IDs into a single file. While the change itself is
a very good one, it can break userspace applications. For example
if a userspace tool wanted to get the ID of virtio_net it used to
include virtio_net.h. This does no longer work, since virtio_net.h
does not include virtio_ids.h.
This patch moves all "#include <linux/virtio_ids.h>" from the C
files into the header files, making the header files compatible with
the old ones.

In addition, this patch exports virtio_ids.h to userspace.

CC: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Because netpoll can call netdevice start_xmit() method with
irqs disabled, drivers should not call kfree_skb() from
their start_xmit(), but use dev_kfree_skb_any() instead.

Oct  8 11:16:52 172.30.1.31 [113074.791813] ------------[ cut here ]------------
Oct  8 11:16:52 172.30.1.31 [113074.791813] WARNING: at net/core/skbuff.c:398 \
                skb_release_head_state+0x64/0xc8()
Oct  8 11:16:52 172.30.1.31 [113074.791813] Hardware name:
Oct  8 11:16:52 172.30.1.31 [113074.791813] Modules linked in: netconsole ocfs2 jbd2 quota_tree \
ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs crc32c drbd cn loop \
serio_raw psmouse snd_pcm snd_timer snd soundcore snd_page_alloc virtio_net pcspkr parport_pc parport \
i2c_piix4 i2c_core button processor evdev ext3 jbd mbcache dm_mirror dm_region_hash dm_log dm_snapshot \
dm_mod ide_cd_mod cdrom ata_generic ata_piix virtio_blk libata scsi_mod piix ide_pci_generic ide_core \
                virtio_pci virtio_ring virtio floppy thermal fan thermal_sys [last unloaded: netconsole]
Oct  8 11:16:52 172.30.1.31 [113074.791813] Pid: 11132, comm: php5-cgi Tainted: G        W  \
                2.6.31.2-vserver #1
Oct  8 11:16:52 172.30.1.31 [113074.791813] Call Trace:
Oct  8 11:16:52 172.30.1.31 [113074.791813] <IRQ>  [<ffffffff81253cd5>] ? \
                skb_release_head_state+0x64/0xc8
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81253cd5>] ? skb_release_head_state+0x64/0xc8
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81049ae1>] ? warn_slowpath_common+0x77/0xa3
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81253cd5>] ? skb_release_head_state+0x64/0xc8
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81253a1a>] ? __kfree_skb+0x9/0x7d
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffffa01cb139>] ? free_old_xmit_skbs+0x51/0x6e \
                [virtio_net]
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffffa01cbc85>] ? start_xmit+0x26/0xf2 [virtio_net]
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff8126934f>] ? netpoll_send_skb+0xd2/0x205
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffffa0429216>] ? write_msg+0x90/0xeb [netconsole]
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81049f06>] ? __call_console_drivers+0x5e/0x6f
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff8102b49d>] ? kvm_clock_read+0x4d/0x52
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff8104a082>] ? release_console_sem+0x115/0x1ba
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff8104a632>] ? vprintk+0x2f2/0x34b
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff8106b142>] ? vx_update_load+0x18/0x13e
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81308309>] ? printk+0x4e/0x5d
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff8102b49d>] ? kvm_clock_read+0x4d/0x52
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81070b62>] ? getnstimeofday+0x55/0xaf
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81062683>] ? ktime_get_ts+0x21/0x49
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff810626b7>] ? ktime_get+0xc/0x41
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81062788>] ? hrtimer_interrupt+0x9c/0x146
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81024a4b>] ? smp_apic_timer_interrupt+0x80/0x93
Oct  8 11:16:52 172.30.1.31 [113074.791813] [<ffffffff81011663>] ? apic_timer_interrupt+0x13/0x20
Oct  8 11:16:52 172.30.1.31 [113074.791813] <EOI>  [<ffffffff8130a9eb>] ? _spin_unlock_irq+0xd/0x31
Reported-and-tested-by: NMassimo Cetra <mcetra@navynet.it>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Bug-Entry: http://bugzilla.kernel.org/show_bug.cgi?id=14378Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function virtnet_remove is used only wrapped by __devexit_p so define
it using __devexit.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Alex Williamson <alex.williamson@hp.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Saves us one cycle of alloc-add-free if the queue was full.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (modified)

Now we can tell the theoretical capacity remaining in the output
queue, virtio_net can waste entries by stopping the queue early.

It doesn't work in the case of indirect buffers and kmalloc failure,
but that's rare (we could drop the packet in that case, but other
drivers return TX_BUSY for similar reasons).

For the record, I think this patch reflects poorly on the linux
network API.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Dinesh Subhraveti <dineshs@us.ibm.com>

We put the virtio_net_hdr into the skb's cb region; turn this into a
union to clean up the code slightly and allow future expansion.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: Dinesh Subhraveti <dineshs@us.ibm.com>

The virtio_net driver is complicated by the two methods of freeing old
xmit buffers (in addition to freeing old ones at the start of the xmit
path).

The original code used a 1/10 second timer attached to xmit_free(),
reset on every xmit.  Before we orphaned skbs on xmit, the
transmitting userspace could block with a full socket until the timer
fired, the skb destructor was called, and they were re-woken.

So we added the VIRTIO_F_NOTIFY_ON_EMPTY feature: supporting devices
send an interrupt (even if normally suppressed) on an empty xmit ring
which makes us schedule xmit_tasklet().  This was a benchmark win.

Unfortunately, VIRTIO_F_NOTIFY_ON_EMPTY makes quite a lot of work: a
host which is faster than the guest will fire the interrupt every xmit
packet (slowing the guest down further).  Attempting mitigation in the
host adds overhead of userspace timers (possibly with the additional
pain of signals), and risks increasing latency anyway if you get it
wrong.

In practice, this effect was masked by benchmarks which take advantage
of GSO (with its inherent transmit batching), but it's still there.

Now we orphan xmitted skbs, the pressure is off: remove both paths and
no longer request VIRTIO_F_NOTIFY_ON_EMPTY.  Note that the current
QEMU will notify us even if we don't negotiate this feature (legal,
but suboptimal); a patch is outstanding to improve that.

Move the skb_orphan/nf_reset to after we've done the send and notified
the other end, for a slight optimization.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Mark McLoughlin <markmc@redhat.com>

This effectively reverts 99ffc696
"virtio: wean net driver off NETDEV_TX_BUSY".

The complexity of queuing an skb (setting a tasklet to re-xmit) is
questionable, especially once we get rid of the other reason for the
tasklet in the next patch.

If the skb won't fit in the tx queue, just return NETDEV_TX_BUSY.
This is frowned upon, so a followup patch uses a more complex solution.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Herbert Xu <herbert@gondor.apana.org.au>

The complex transmit free logic was introduced to avoid hangs on
removing the ip_conntrack module and also because drivers aren't
generally supposed to keep stale skbs for unbounded times.

After some debate, it was decided that while doing skb_orphan()
generally is a rat's nest, we can do it in this driver.  Following
patches take advantage of this.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Virtio IDs are spread all over the tree which makes assigning new IDs
bothersome. Putting them together should make the process less error-prone.
Signed-off-by: NFernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This API change means that virtio_net can tell how much capacity
remains for buffers.  It's necessarily fuzzy, since
VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors
in one, *if* we can kmalloc.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Dinesh Subhraveti <dineshs@us.ibm.com>

No need to put ethtool_ops in data, they should be const.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These are all drivers that don't touch real hardware.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If we run out of memory, use keventd to fill the buffer.  There's a
report of this happening: "Page allocation failures in guest",
Message-ID: <20090713115158.0a4892b0@mjolnir.ossman.eu>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- Allow setting UFO on virtio-net and advertise to host.
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is inspired by patch recently posted by Johannes Berg. Basically what
my patch does is to group list and a count of addresses into newly introduced
structure netdev_hw_addr_list. This brings us two benefits:
1) struct net_device becames a bit nicer.
2) in the future there will be a possibility to operate with lists independently
   on netdevices (with exporting right functions).
I wanted to introduce this patch before I'll post a multicast lists conversion.
Signed-off-by: NJiri Pirko <jpirko@redhat.com>

 drivers/net/bnx2.c              |    4 +-
 drivers/net/e1000/e1000_main.c  |    4 +-
 drivers/net/ixgbe/ixgbe_main.c  |    6 +-
 drivers/net/mv643xx_eth.c       |    2 +-
 drivers/net/niu.c               |    4 +-
 drivers/net/virtio_net.c        |   10 ++--
 drivers/s390/net/qeth_l2_main.c |    2 +-
 include/linux/netdevice.h       |   17 +++--
 net/core/dev.c                  |  130 ++++++++++++++++++--------------------
 9 files changed, 89 insertions(+), 90 deletions(-)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations,
and updates all drivers. This is needed for MSI support, because MSI
needs to know the total number of vectors upfront.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)

Add a linked list of all virtqueues for a virtio device: this helps for
debugging and is also needed for upcoming interface change.

Also, add a "name" field for clearer debug messages.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

We need to enforce the IP alignment on the non-mergeable RX path just
like the other RX path.  Not doing so results in misaligned IP
headers.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Through a bug in the tun driver, I noticed that virtio_net is
producing bogus hdr_len values.  In particular, it only includes
the IP header in the linear area, and excludes the entire TCP
header.  This causes the TCP header to be copied twice for each
packet.  (The bug omitted the second copy :)

This patch corrects this.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch converts unicast address list to standard list_head using
previously introduced struct netdev_hw_addr. It also relaxes the
locking. Original spinlock (still used for multicast addresses) is not
needed and is no longer used for a protection of this list. All
reading and writing takes place under rtnl (with no changes).

I also removed a possibility to specify the length of the address
while adding or deleting unicast address. It's always dev->addr_len.

The convertion touched especially e1000 and ixgbe codes when the
change is not so trivial.
Signed-off-by: NJiri Pirko <jpirko@redhat.com>

 drivers/net/bnx2.c               |   13 +--
 drivers/net/e1000/e1000_main.c   |   24 +++--
 drivers/net/ixgbe/ixgbe_common.c |   14 ++--
 drivers/net/ixgbe/ixgbe_common.h |    4 +-
 drivers/net/ixgbe/ixgbe_main.c   |    6 +-
 drivers/net/ixgbe/ixgbe_type.h   |    4 +-
 drivers/net/macvlan.c            |   11 +-
 drivers/net/mv643xx_eth.c        |   11 +-
 drivers/net/niu.c                |    7 +-
 drivers/net/virtio_net.c         |    7 +-
 drivers/s390/net/qeth_l2_main.c  |    6 +-
 drivers/scsi/fcoe/fcoe.c         |   16 ++--
 include/linux/netdevice.h        |   18 ++--
 net/8021q/vlan.c                 |    4 +-
 net/8021q/vlan_dev.c             |   10 +-
 net/core/dev.c                   |  195 +++++++++++++++++++++++++++-----------
 net/dsa/slave.c                  |   10 +-
 net/packet/af_packet.c           |    4 +-
 18 files changed, 227 insertions(+), 137 deletions(-)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We were avoiding calling sg_init* on scatterlists passed
into virtnet_send_command to prevent extraneous end markers.
This caused build warnings for uninitialized variables.
Cleanup the code to create proper scatterlists.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

VIRTIO_NET_F_MAC indicates the presence of the mac field in config
space, not the validity of the value it contains.  Allow the mac to be
changed at runtime, but only push the change into config space with the
VIRTIO_NET_F_MAC feature present.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Impact: Make NetworkManager work with virtio_net

For now the semantics are simple: There is always carrier.

This allows a seamless experience with e.g., qemu/kvm
where NetworkManager just configures and sets up
everything automagically.

If/when a generally agreed-upon way to control
carrier on/off in the emulator/hypervisor level
emerges, it will be trivial to extend the driver
to support that too, but for now even this 2-liner
makes user experience that much better.
Signed-off-by: NPantelis Koukousoulas <pktoss@gmail.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many physical NICs let the OS re-program the "hardware" MAC
address.  Virtual NICs should allow this too.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Acked-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

VLAN filtering allows the hypervisor to drop packets from VLANs
that we're not a part of, further reducing the number of extraneous
packets recieved.  This makes use of the VLAN virtqueue command class.
The CTRL_VLAN feature bit tells us whether the backend supports VLAN
filtering.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make use of the MAC control virtqueue class to support a MAC
filter table.  The filter table is managed by the hypervisor.
We consider the table to be available if the CTRL_RX feature
bit is set.  We leave it to the hypervisor to manage the table
and enable promiscuous or all-multi mode as necessary depending
on the resources available to it.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make use of the RX_MODE control virtqueue class to enable the
set_rx_mode netdev interface.  This allows us to selectively
enable/disable promiscuous and allmulti mode so we don't see
packets we don't want.  For now, we automatically enable these
as needed if additional unicast or multicast addresses are
requested.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This will be used for RX mode, MAC filter table, VLAN filtering, etc...

The control transaction consists of one or more "out" sg entries and
one or more "in" sg entries.  The first out entry contains a header
defining the class and command.  Additional out entries may provide
data for the command.  The last in entry provides a status response
back from the command.

Virtqueues typically run asynchronous, running a callback function
when there's data in the channel.  We can't readily make use of this
in the command paths where we need to use this.  Instead, we kick
the virtqueue and spin.  The kick causes an I/O write, triggering an
immediate trap into the hypervisor.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>