linux.git/drivers/net/macvtap.c, branch v3.11

macvtap: Ignore tap features when VNET_HDR is off

2013-08-20T20:09:12+00:00

When the user turns off VNET_HDR support on the
macvtap device, there is no way to provide any
offload information to the user.  So, it's safer
to ignore offload setting then depend on the user
setting them correctly.

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

macvtap: Correctly set tap features when IFF_VNET_HDR is disabled.

2013-08-20T20:09:11+00:00

When the user turns off IFF_VNET_HDR flag, attempts to change
offload features via TUNSETOFFLOAD do not work.  This could cause
GSO packets to be delivered to the user when the user is
not prepared to handle them.

To solve, allow processing of TUNSETOFFLOAD when IFF_VNET_HDR is
disabled.

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

macvtap: simplify usage of tap_features

2013-08-20T20:09:11+00:00

In macvtap, tap_features specific the features of that the user
has specified via ioctl().  If we treat macvtap as a macvlan+tap
then we could all the tap a pseudo-device and give it other features
like SG and GSO.  Then we can stop using the features of lower
device (macvlan) when forwarding the traffic the tap.

This solves the issue of possible checksum offload mismatch between
tap feature and macvlan features.

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller

macvtap: fix two races

2013-08-12T04:48:58+00:00

Since commit ac4e4af1e59e1 ("macvtap: Consistently use rcu functions"),
Thomas gets two different warnings :

BUG: using smp_processor_id() in preemptible [00000000] code: vhost-45891/45892
caller is macvtap_do_read+0x45c/0x600 [macvtap]
CPU: 1 PID: 45892 Comm: vhost-45891 Not tainted 3.11.0-bisecttest #13
Call Trace:
([<00000000001126ee>] show_trace+0x126/0x144)
 [<00000000001127d2>] show_stack+0xc6/0xd4
 [<000000000068bcec>] dump_stack+0x74/0xd8
 [<0000000000481066>] debug_smp_processor_id+0xf6/0x114
 [<000003ff802e9a18>] macvtap_do_read+0x45c/0x600 [macvtap]
 [<000003ff802e9c1c>] macvtap_recvmsg+0x60/0x88 [macvtap]
 [<000003ff80318c5e>] handle_rx+0x5b2/0x800 [vhost_net]
 [<000003ff8028f77c>] vhost_worker+0x15c/0x1c4 [vhost]
 [<000000000015f3ac>] kthread+0xd8/0xe4
 [<00000000006934a6>] kernel_thread_starter+0x6/0xc
 [<00000000006934a0>] kernel_thread_starter+0x0/0xc

And

BUG: using smp_processor_id() in preemptible [00000000] code: vhost-45897/45898
caller is macvlan_start_xmit+0x10a/0x1b4 [macvlan]
CPU: 1 PID: 45898 Comm: vhost-45897 Not tainted 3.11.0-bisecttest #16
Call Trace:
([<00000000001126ee>] show_trace+0x126/0x144)
 [<00000000001127d2>] show_stack+0xc6/0xd4
 [<000000000068bdb8>] dump_stack+0x74/0xd4
 [<0000000000481132>] debug_smp_processor_id+0xf6/0x114
 [<000003ff802b72ca>] macvlan_start_xmit+0x10a/0x1b4 [macvlan]
 [<000003ff802ea69a>] macvtap_get_user+0x982/0xbc4 [macvtap]
 [<000003ff802ea92a>] macvtap_sendmsg+0x4e/0x60 [macvtap]
 [<000003ff8031947c>] handle_tx+0x494/0x5ec [vhost_net]
 [<000003ff8028f77c>] vhost_worker+0x15c/0x1c4 [vhost]
 [<000000000015f3ac>] kthread+0xd8/0xe4
 [<000000000069356e>] kernel_thread_starter+0x6/0xc
 [<0000000000693568>] kernel_thread_starter+0x0/0xc
2 locks held by vhost-45897/45898:
 #0:  (&vq->mutex){+.+.+.}, at: [<000003ff8031903c>] handle_tx+0x54/0x5ec [vhost_net]
 #1:  (rcu_read_lock){.+.+..}, at: [<000003ff802ea53c>] macvtap_get_user+0x824/0xbc4 [macvtap]

In the first case, macvtap_put_user() calls macvlan_count_rx()
in a preempt-able context, and this is not allowed.

In the second case, macvtap_get_user() calls
macvlan_start_xmit() with BH enabled, and this is not allowed.

Reported-by: Thomas Huth 
Bisected-by: Thomas Huth 
Signed-off-by: Eric Dumazet 
Tested-by: Thomas Huth 
Cc: Vlad Yasevich 
Signed-off-by: David S. Miller

macvtap: do not zerocopy if iov needs more pages than MAX_SKB_FRAGS

2013-07-18T20:04:25+00:00

We try to linearize part of the skb when the number of iov is greater than
MAX_SKB_FRAGS. This is not enough since each single vector may occupy more than
one pages, so zerocopy_sg_fromiovec() may still fail and may break the guest
network.

Solve this problem by calculate the pages needed for iov before trying to do
zerocopy and switch to use copy instead of zerocopy if it needs more than
MAX_SKB_FRAGS.

This is done through introducing a new helper to count the pages for iov, and
call uarg->callback() manually when switching from zerocopy to copy to notify
vhost.

We can do further optimization on top.

This bug were introduced from b92946e2919134ebe2a4083e4302236295ea2a73
(macvtap: zerocopy: validate vectors before building skb).

Cc: Michael S. Tsirkin 
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller

macvtap: do not assume 802.1Q when send vlan packets

2013-07-16T20:01:57+00:00

The hard-coded 8021.q proto will break 802.1ad traffic. So switch to use
vlan->proto.

Cc: Basil Gor 
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller

macvtap: fix the missing ret value of TUNSETQUEUE

2013-07-16T20:01:57+00:00

Commit 441ac0fcaadc76ad09771812382345001dd2b813
(macvtap: Convert to using rtnl lock) forget to return what
macvtap_ioctl_set_queue() returns to its caller. This may break multiqueue API
by always falling through to TUNGETFEATURES.

Cc: Vlad Yasevich 
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller

macvtap: correctly linearize skb when zerocopy is used

2013-07-11T01:45:52+00:00

Userspace may produce vectors greater than MAX_SKB_FRAGS. When we try to
linearize parts of the skb to let the rest of iov to be fit in
the frags, we need count copylen into linear when calling macvtap_alloc_skb()
instead of partly counting it into data_len. Since this breaks
zerocopy_sg_from_iovec() since its inner counter assumes nr_frags should
be zero at beginning. This cause nr_frags to be increased wrongly without
setting the correct frags.

This bug were introduced from b92946e2919134ebe2a4083e4302236295ea2a73
(macvtap: zerocopy: validate vectors before building skb).

Cc: Michael S. Tsirkin 
Signed-off-by: Jason Wang 
Acked-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2013-07-03T21:55:13+00:00

Conflicts:
	drivers/net/ethernet/freescale/fec_main.c
	drivers/net/ethernet/renesas/sh_eth.c
	net/ipv4/gre.c

The GRE conflict is between a bug fix (kfree_skb --> kfree_skb_list)
and the splitting of the gre.c code into seperate files.

The FEC conflict was two sets of changes adding ethtool support code
in an "!CONFIG_M5272" CPP protected block.

Finally the sh_eth.c conflict was between one commit add bits set
in the .eesr_err_check mask whilst another commit removed the
.tx_error_check member and assignments.

Signed-off-by: David S. Miller

macvtap: Perform GSO on forwarding path.

2013-06-25T23:45:23+00:00

When macvtap forwards skb to its tap, it needs to check
if GSO needs to be performed.  This is sometimes necessary
when the HW device performed GRO, but the guest reading
from the tap does not support it (ex: Windows 7).

Signed-off-by: Vlad Yasevich 
Signed-off-by: David S. Miller