Commit Graph

165 Commits

Author SHA1 Message Date
stephen hemminger
dc54a08cd3 netvsc: optimize receive path
Do manual optimizations of receive path:
  - remove checks for impossible conditions (but keep checks
    for bad data from host)
  - pass argument down, rather than having callee recompute what
    is already known
  - remove indirection about receive buffer datalength
  - remove dependence on VLAN_TAG_PRESENCE
  - use _hot/_cold and likely/unlikely

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:29:00 -05:00
stephen hemminger
b8b835a89b netvsc: group all per-channel state together
Put all the per-channel state together in one data struct.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:28:59 -05:00
stephen hemminger
ceaaea0483 netvsc: remove unused variables
Fixes set but never used warnings

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:28:59 -05:00
stephen hemminger
d8e18ee0fa netvsc: enhance transmit select_queue
The netvsc select queue function was missing many of the flow caching
features that exist in default tx queue selection. Add the same
logic to remember queue based on socket and implement two level
mapping (like RSS).

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:28:59 -05:00
stephen hemminger
ff4a441990 netvsc: allow get/set of RSS indirection table
Allow setting receive indirection table. Also uses the system standard
for initialization.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:28:59 -05:00
stephen hemminger
2b01888d1b netvsc: allow more flexible setting of number of channels
This allows for number of channels to be managed in a manner similar
to existing hardware drivers. It also removes the restriction of
maximum 8 channels and allows as many as the host will allow.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:28:58 -05:00
stephen hemminger
962f3fee83 netvsc: add ethtool ops to get/set RSS key
For some cases it is useful to be able to change RSS key value.
For example, replacing RSS key with a symmetric hash.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:28:58 -05:00
stephen hemminger
b5a5dc8dc8 netvsc: report rss field values
Report current components used in RSS hash.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:28:58 -05:00
stephen hemminger
b448f4e892 netvsc: report number of rx queues in ethtool
Report actual number of receive queues to ethtool.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:28:58 -05:00
stephen hemminger
23312a3be9 netvsc: negotiate checksum and segmentation parameters
Redo how Hyper-V network driver negotiates offload features. Query the
host to determine offload settings, and use the result.

Also:
  * disable IPv4 header checksum offload (not used by Linux)
  * enable TSO only if host supports
  * enable UDP checksum offload if supported
  * don't advertise support for checksumming of non-IP protocols
  * adjust GSO maximum segment size
  * enable HIGHDMA

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:28:57 -05:00
David S. Miller
580bdf5650 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-17 15:19:37 -05:00
stephen hemminger
0719e72ccb netvsc: add rcu_read locking to netvsc callback
The receive callback (in tasklet context) is using RCU to get reference
to associated VF network device but this is not safe. RCU read lock
needs to be held. Found by running with full lockdep debugging
enabled.

Fixes: f207c10d98 ("hv_netvsc: use RCU to protect vf_netdev")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-11 16:13:53 -05:00
stephen hemminger
bc1f44709c net: make ndo_get_stats64 a void function
The network device operation for reading statistics is only called
in one place, and it ignores the return value. Having a structure
return value is potentially confusing because some future driver could
incorrectly assume that the return value was used.

Fix all drivers with ndo_get_stats64 to have a void function.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-08 17:51:44 -05:00
David S. Miller
821781a9f4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-10 16:21:55 -05:00
stephen hemminger
a50af86dd4 netvsc: reduce maximum GSO size
Hyper-V (and Azure) support using NVGRE which requires some extra space
for encapsulation headers. Because of this the largest allowed TSO
packet is reduced.

For older releases, hard code a fixed reduced value.  For next release,
there is a better solution which uses result of host offload
negotiation.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-07 13:13:41 -05:00
David S. Miller
27058af401 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Mostly simple overlapping changes.

For example, David Ahern's adjacency list revamp in 'net-next'
conflicted with an adjacency list traversal bug fix in 'net'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-30 12:42:58 -04:00
Stephen Hemminger
e934f68485 Revert "hv_netvsc: report vmbus name in ethtool"
This reverts commit e3f74b841d
("hv_netvsc: report vmbus name in ethtool")'
because of problem introduced by commit f9a56e5d6a0ba
("Drivers: hv: make VMBus bus ids persistent").
This changed the format of the vmbus name and this new format is too
long to fit in the bus_info field of ethtool.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-29 15:03:14 -04:00
Stephen Hemminger
e52fed7177 netvsc: fix incorrect receive checksum offloading
The Hyper-V netvsc driver was looking at the incorrect status bits
in the checksum info. It was setting the receive checksum unnecessary
flag based on the IP header checksum being correct. The checksum
flag is skb is about TCP and UDP checksum status. Because of this
bug, any packet received with bad TCP checksum would be passed
up the stack and to the application causing data corruption.
The problem is reproducible via netcat and netem.

This had a side effect of not doing receive checksum offload
on IPv6. The driver was also also always doing checksum offload
independent of the checksum setting done via ethtool.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-26 23:18:36 -04:00
Jarod Wilson
d0c2c9973e net: use core MTU range checking in virt drivers
hyperv_net:
- set min/max_mtu, per Haiyang, after rndis_filter_device_add

virtio_net:
- set min/max_mtu
- remove virtnet_change_mtu

vmxnet3:
- set min/max_mtu

xen-netback:
- min_mtu = 0, max_mtu = 65517

xen-netfront:
- min_mtu = 0, max_mtu = 65535

unisys/visor:
- clean up defines a little to not clash with network core or add
  redundat definitions

CC: netdev@vger.kernel.org
CC: virtualization@lists.linux-foundation.org
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: "Michael S. Tsirkin" <mst@redhat.com>
CC: Shrikrishna Khare <skhare@vmware.com>
CC: "VMware, Inc." <pv-drivers@vmware.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: Paul Durrant <paul.durrant@citrix.com>
CC: David Kershner <david.kershner@unisys.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-20 14:51:09 -04:00
Arnd Bergmann
52ccd63184 net/hyperv: avoid uninitialized variable
The hdr_offset variable is only if we deal with a TCP or UDP packet,
but as the check surrounding its usage tests for skb_is_gso()
instead, the compiler has no idea if the variable is initialized
or not at that point:

drivers/net/hyperv/netvsc_drv.c: In function ‘netvsc_start_xmit’:
drivers/net/hyperv/netvsc_drv.c:494:42: error: ‘hdr_offset’ may be used uninitialized in this function [-Werror=maybe-uninitialized]

This adds an additional check for the transport type, which
tells the compiler that this path cannot happen. Since the
get_net_transport_info() function should always be inlined
here, I don't expect this to result in additional runtime
checks.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-18 14:20:36 -04:00
David S. Miller
3f2b0a5a35 netvsc: Remove mistaken udp.h inclusion.
Based upon v2 of Stephen's patch.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-13 11:04:07 -04:00
stephen hemminger
ad19bc8a95 netvsc: fix checksum on UDP IPV6
The software calculation of UDP checksum in Netvsc driver was
only handling IPv4 case. By using skb_checksum_help() instead
all protocols can be handled. Rearrange code to eliminate goto
and look like other drivers.

This is a temporary solution; recent versions of Window Server etc
do support UDP checksum offload, just need to do the appropriate negotiation
with host to validate before using. This will be done in later patch.

Please queue this for -stable as well.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-13 10:48:17 -04:00
Stephen Hemminger
f7ad75b753 hv_netvsc: count multicast packets received
Useful for debugging issues with multicast and SR-IOV to keep track
of number of received multicast packets.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-23 08:39:49 -04:00
Stephen Hemminger
9cbcc42806 hv_netvsc: remove VF in flight counters
Since VF reference is now protected by RCU, no longer need the VF usage
counter and can use device flags to see whether to inject or not.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-23 08:39:49 -04:00
Stephen Hemminger
f207c10d98 hv_netvsc: use RCU to protect vf_netdev
The vf_netdev pointer in the netvsc device context can simply be protected
by RCU because network device destruction is already RCU synchronized.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-23 08:39:49 -04:00
Stephen Hemminger
e8ff40d4bf hv_netvsc: improve VF device matching
The code to associate netvsc and VF devices can be made less error prone
by using a better matching algorithms.

On registration, use the permanent address which avoids any possible
issues caused by device MAC address being changed. For all other callbacks,
search by the netdevice pointer value to ensure getting the correct
network device.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-23 08:39:49 -04:00
Stephen Hemminger
ee837a1373 hv_netvsc: simplify callback event code
The callback handler for netlink events can be simplified:
 * Consolidate check for netlink callback events about this driver itself.
 * Ignore non-Ethernet devices.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-23 08:39:49 -04:00
Stephen Hemminger
07d0f0008c hv_netvsc: dev hold/put reference to VF
The netvsc driver holds a pointer to the virtual function network device if
managing SR-IOV association. In order to ensure that the VF network device
does not disappear, it should be using dev_hold/dev_put to get a reference
count.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-23 08:39:48 -04:00
Stephen Hemminger
4323b47cf8 hv_netvsc: add ethtool statistics for tx packet issues
Printing console messages is not helpful when system is out of memory;
and can be disastrous with netconsole. Instead keep statistics
of these anomalous conditions.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23 12:05:38 -07:00
Stephen Hemminger
e3f74b841d hv_netvsc: report vmbus name in ethtool
Make netvsc on vmbus behave more like PCI.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23 12:05:38 -07:00
Stephen Hemminger
0ab05141f9 hv_netvsc: rearrange start_xmit
Rearrange the transmit routine to eliminate goto's and unnecessary
boolean variables. Use standard functions to test for vlan tag.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23 12:05:37 -07:00
Stephen Hemminger
796cc88c32 hv_netvsc: style cleanups
Fix most of the complaints about the style of the code.
Things like extra blank lines and return statements.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23 12:05:36 -07:00
Stephen Hemminger
8737caafd1 hv_netvsc: fix rtnl locking in callback
The function get_netvsc_net_device had conditional locking. This was
unnecessary, incorrect, but harmless. It was unnecessary since the
code is only called from netlink netdev event callback where RTNL
is always acquired before the callbacks are run. It was incorrect
because of use of trylock and then continuing.
Fix by replacing with proper assertion.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23 12:05:35 -07:00
David S. Miller
60747ef4d1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor overlapping changes for both merge conflicts.

Resolution work done by Stephen Rothwell was used
as a reference.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-18 01:17:32 -04:00
Vitaly Kuznetsov
0dbff144a1 hv_netvsc: fix bonding devices check in netvsc_netdev_event()
Bonding driver sets IFF_BONDING on both master (the bonding device) and
slave (the real NIC) devices and in netvsc_netdev_event() we want to skip
master devices only. Currently, there is an uncertainty when a slave
interface is removed: if bonding module comes first in netdev_chain it
clears IFF_BONDING flag on the netdev and netvsc_netdev_event() correctly
handles NETDEV_UNREGISTER event, but in case netvsc comes first on the
chain it sees the device with IFF_BONDING still attached and skips it. As
we still hold vf_netdev pointer to the device we crash on the next inject.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 13:48:07 -07:00
Vitaly Kuznetsov
0f20d795f7 hv_netvsc: protect module refcount by checking net_device_ctx->vf_netdev
We're not guaranteed to see NETDEV_REGISTER/NETDEV_UNREGISTER notifications
only once per VF but we increase/decrease module refcount unconditionally.
Check vf_netdev to make sure we don't take/release it twice. We presume
that only one VF per netvsc device may exist.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 13:48:07 -07:00
Vitaly Kuznetsov
57c1826b99 hv_netvsc: reset vf_inject on VF removal
We reset vf_inject on VF going down (netvsc_vf_down()) but we don't on
VF removal (netvsc_unregister_vf()) so vf_inject stays 'true' while
vf_netdev is already NULL and we're trying to inject packets into NULL
net device in netvsc_recv_callback() causing kernel to crash.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 13:48:07 -07:00
Vitaly Kuznetsov
d072218f21 hv_netvsc: avoid deadlocks between rtnl lock and vf_use_cnt wait
Here is a deadlock scenario:
- netvsc_vf_up() schedules netvsc_notify_peers() work and quits.
- netvsc_vf_down() runs before netvsc_notify_peers() gets executed. As it
  is being executed from netdev notifier chain we hold rtnl lock when we
  get here.
- we enter while (atomic_read(&net_device_ctx->vf_use_cnt) != 0) loop and
  wait till netvsc_notify_peers() drops vf_use_cnt.
- netvsc_notify_peers() starts on some other CPU but netdev_notify_peers()
  will hang on rtnl_lock().
- deadlock!

Instead of introducing additional synchronization I suggest we drop
gwrk.dwrk completely and call NETDEV_NOTIFY_PEERS directly. As we're
acting under rtnl lock this is legitimate.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 13:48:07 -07:00
Vitaly Kuznetsov
f9a7da9130 hv_netvsc: don't lose VF information
struct netvsc_device is not suitable for storing VF information as this
structure is being destroyed on MTU change / set channel operation (see
rndis_filter_device_remove()). Move all VF related stuff to struct
net_device_context which is persistent.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 13:48:07 -07:00
Haiyang Zhang
7f5d5af0b2 hv_netvsc: Add handler for physical link speed change
On Hyper-V host 2016 and later, VMs gets an event message of the physical
link speed when vSwitch is changed. This patch handles this message, so
the updated link speed can be reported by ethtool.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08 16:14:07 -07:00
Haiyang Zhang
b37879e6ca hv_netvsc: Add query for initial physical link speed
The physical link speed value will be reported by ethtool command.
The real speed is available from Windows 2016 host or later.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08 16:14:07 -07:00
Haiyang Zhang
e2b9f1f7af hv_netvsc: Fix VF register on bonding devices
Added a condition to avoid bonding devices with same MAC registering
as VF.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-25 11:19:22 -07:00
Vitaly Kuznetsov
e834da9a40 hv_netvsc: pass struct net_device to rndis_filter_set_device_mac()
We unpack 'struct net_device' in netvsc_set_mac_addr() to get to
'struct hv_device' pointer which we use in rndis_filter_set_device_mac()
to get back to 'struct net_device'.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-05 23:16:36 -04:00
Vitaly Kuznetsov
2f5fa6c869 hv_netvsc: pass struct netvsc_device to rndis_filter_{open, close}()
Both rndis_filter_open()/rndis_filter_close() use struct hv_device to
reach to struct netvsc_device only and all callers have it already.
While on it, rename net_device to nvdev in rndis_filter_open() as
net_device is misleading.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-05 23:16:36 -04:00
Vitaly Kuznetsov
4baa994dc9 hv_netvsc: remove redundant assignment in netvsc_recv_callback()
net_device_ctx is assigned in the very beginning of the function and 'net'
pointer doesn't change.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-05 23:16:35 -04:00
Haiyang Zhang
cb2911fed6 hv_netvsc: Fix VF register on vlan devices
Added a condition to avoid vlan devices with same MAC registering
as VF.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-03 19:40:05 -04:00
Vitaly Kuznetsov
6da7225f5a hv_netvsc: synchronize netvsc_change_mtu()/netvsc_set_channels() with netvsc_remove()
When netvsc device is removed during mtu change or channels setup we get
into troubles as both paths are trying to remove the device. Synchronize
them with start_remove flag and rtnl lock.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16 13:26:01 -04:00
Vitaly Kuznetsov
0a1275ca51 hv_netvsc: get rid of struct net_device pointer in struct netvsc_device
Simplify netvsvc pointer graph by getting rid of the redundant ndev
pointer. We can always get a pointer to struct net_device from somewhere
else.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16 13:26:00 -04:00
Vitaly Kuznetsov
3d541ac5a9 hv_netvsc: untangle the pointer mess
We have the following structures keeping netvsc adapter state:
- struct net_device
- struct net_device_context
- struct netvsc_device
- struct rndis_device
- struct hv_device
and there are pointers/dependencies between them:
- struct net_device_context is contained in struct net_device
- struct hv_device has driver_data pointer which points to
  'struct net_device' OR 'struct netvsc_device' depending on driver's
  state (!).
- struct net_device_context has a pointer to 'struct hv_device'.
- struct netvsc_device has pointers to 'struct hv_device' and
  'struct net_device_context'.
- struct rndis_device has a pointer to 'struct netvsc_device'.

Different functions get different structures as parameters and use these
pointers for traveling. The problem is (in addition to keeping in mind
this complex graph) that some of these structures (struct netvsc_device
and struct rndis_device) are being removed and re-created on mtu change
(as we implement it as re-creation of hyper-v device) so our travel using
these pointers is dangerous.

Simplify this to a the following:
- add struct netvsc_device pointer to struct net_device_context (which is
  a part of struct net_device and thus never disappears)
- remove struct hv_device and struct net_device_context pointers from
  struct netvsc_device
- replace pointer to 'struct netvsc_device' with pointer to
  'struct net_device'.
- always keep 'struct net_device' in hv_device driver_data.

We'll end up with the following 'circular' structure:

net_device:
 [net_device_context] -> netvsc_device -> rndis_device -> net_device
                      -> hv_device -> net_device

On MTU change we'll be removing the 'netvsc_device -> rndis_device'
branch and re-creating it making the synchronization easier.

There is one additional redundant pointer left, it is struct net_device
link in struct netvsc_device, it is going to be removed in a separate
commit.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16 13:26:00 -04:00
Vitaly Kuznetsov
1bdcec8a5f hv_netvsc: use start_remove flag to protect netvsc_link_change()
netvsc_link_change() can race with netvsc_change_mtu() or
netvsc_set_channels() as these functions destroy struct netvsc_device and
rndis filter. Use start_remove flag for syncronization. As
netvsc_change_mtu()/netvsc_set_channels() are called with rtnl lock held
we need to take it before checking start_remove value in
netvsc_link_change().

Reported-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16 13:26:00 -04:00