Intel did some benchmarking on our network throughput when Linux on Hyper-V
is as used as a gateway. This fix gave us almost a 1 Gbps additional throughput
on about 5Gbps base throughput we hadi, prior to increasing the sendbuf size.
The sendbuf mechanism is a copy based transport that we have which is clearly
more optimal than the copy-free page flipping mechanism (for small packets).
In the forwarding scenario, we deal only with MTU sized packets,
and increasing the size of the senbuf area gave us the additional performance.
For what it is worth, Windows guests on Hyper-V, I am told use similar sendbuf
size as well.

The exact value of sendbuf I think is less important than the fact that it needs
to be larger than what Linux can allocate as physically contiguous memory.
Thus the change over to allocating via vmalloc().

We currently allocate 16MB receive buffer and we use vmalloc there for allocation.
Also the low level channel code has already been modified to deal with physically
dis-contiguous memory in the ringbuffer setup.

Based on experimentation Intel did, they say there was some improvement in throughput
as the sendbuf size was increased up to 16MB and there was no effect on throughput
beyond 16MB. Thus I have chosen 16MB here.

Increasing the sendbuf value makes a material difference in small packet handling

In this version of the patch, based on David's feedback, I have added
additional details in the commit log.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix to return -ENOMEM from the kalloc error handling
case instead of 0.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to have at least a netconsole to debug kernel issues on
Windows Azure this patch implements netpoll support.
Sending packets is easy, netvsc_start_xmit() does already everything
needed.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Acked-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix checkpatch warning:
WARNING: kfree(NULL) is safe this check is probably not required

Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: netdev@vger.kernel.org
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The RNDIS_STATUS_NETWORK_CHANGE event is received after the Hyper-V host
sleep or hibernation. We refresh network at this time.
MS-TFS: 135162
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

c25aaf81: "hyperv: Enable sendbuf mechanism on the send path" added
some teardown code that looks like it was copied from the recieve path
above, but missed a variable name replacement.
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It passes the hash value as the RNDIS Per-packet info to the Hyper-V host,
so that the send completion notices can be spread across multiple channels.
MS-TFS: 140273
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net: get rid of SET_ETHTOOL_OPS

Dave Miller mentioned he'd like to see SET_ETHTOOL_OPS gone.
This does that.

Mostly done via coccinelle script:
@@
struct ethtool_ops *ops;
struct net_device *dev;
@@
-       SET_ETHTOOL_OPS(dev, ops);
+       dev->ethtool_ops = ops;

Compile tested only, but I'd seriously wonder if this broke anything.
Suggested-by: NDave Miller <davem@davemloft.net>
Signed-off-by: NWilfried Klaebe <w-lkml@lebenslange-mailadresse.de>
Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change ensures the driver can be built successfully without the
CONFIG_SYSFS flag.
MS-TFS: 182270
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do checksum offload only if the client of the driver wants checksum to be
offloaded.

In V1 version of this patch, I  addressed comments from
Stephen Hemminger <stephen@networkplumber.org> and
Eric Dumazet <eric.dumazet@gmail.com>.

In this version of the patch I have addressed comments from
David Miller.

This patch fixes a bug that is exposed in gateway scenarios.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We send packets using a copy-free mechanism (this is the Guest to Host transport
via VMBUS). While this is obviously optimal for large packets,
it may not be optimal for small packets. Hyper-V host supports
a second mechanism for sending packets that is "copy based". We implement that
mechanism in this patch.

In this version of the patch I have addressed a comment from David Miller.

With this patch (and all of the other offload and VRSS patches), we are now able
to almost saturate a 10G interface between Linux VMs on Hyper-V
on different hosts - close to  9 Gbps as measured via iperf.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The union contains only one member now, so we use the variables in it directly.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Removed recv_pkt_list and lock, and updated related code, so that
the locking overhead is reduced especially when multiple channels
are in use.

The recv_pkt_list isn't actually necessary because the packets are
processed sequentially in each channel. It has been replaced by a
local variable, and the related lock for this list is also removed.
The is_data_pkt field is not used in receive path, so its assignment
is cleaned up.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This feature allows multiple channels to be used by each virtual NIC.
It is available on Hyper-V host 2012 R2.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ws2008r2 does not support UDP checksum offload. Thus, we cannnot turn on
UDP offload in the host. Also, on ws2012 and ws2012 r2, there appear to be
an issue with UDP checksum offload.
Fix this issue by computing the UDP checksum in the Hyper-V driver.

Based on Dave Miller's comments, in this version, I have COWed the skb
before modifying the UDP header (the checksum field).
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ws2008R2 supports ndis_version 6.1 and 6.1 is the minimal version required
for various offloads. Negotiate ndis_version 6.1 when on ws2008r2.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

An outgoing packet can potentially need per-packet information for
all the offloads and VLAN tagging. Fix this issue.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to a bug in the Hyper-V host verion 2008R2, we need to use a slightly smaller
receive buffer size, otherwise the buffer will not be accepted by the legacy hosts.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Enable segmentation offload.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Enable send side checksum offload.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Enable receive side checksum offload.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Prior to enabling guest side offloads, enable the offloads on the host.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for enabling offloads, cleanup the send path.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Cleanup the code and enable scatter gather I/O.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It moves the state setting for query into rndis_filter_receive_response().
All callbacks including query-complete and status-callback are synchronized
by channel->inbound_lock. This prevents pentential race between them.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It auto negotiates the highest NetVSP version supported by both guest and host.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Get rid of the buffer allocation in the receive path for normal packets.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make the receive path a little more efficient by parameterizing the
required state rather than re-establishing that state.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This structure is redundant; get rid of it make the code little more efficient -
get rid of the unnecessary indirection.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Without this patch, the "cat /sys/class/net/ethN/operstate" shows
"unknown", and "ethtool ethN" shows "Link detected: yes", when VM
boots up with or without vNIC connected.

This patch fixed the problem.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This will allow us to use bigger receive buffer, and prevent allocation failure
due to fragmented memory.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Moving the register_netdev to the end of probe to prevent
possible open call happens before NetVSP is connected.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There's a possible deadlock if we flush the peers notifying work during setting
mtu:

[   22.991149] ======================================================
[   22.991173] [ INFO: possible circular locking dependency detected ]
[   22.991198] 3.10.0-54.0.1.el7.x86_64.debug #1 Not tainted
[   22.991219] -------------------------------------------------------
[   22.991243] ip/974 is trying to acquire lock:
[   22.991261]  ((&(&net_device_ctx->dwork)->work)){+.+.+.}, at: [<ffffffff8108af95>] flush_work+0x5/0x2e0
[   22.991307]
but task is already holding lock:
[   22.991330]  (rtnl_mutex){+.+.+.}, at: [<ffffffff81539deb>] rtnetlink_rcv+0x1b/0x40
[   22.991367]
which lock already depends on the new lock.

[   22.991398]
the existing dependency chain (in reverse order) is:
[   22.991426]
-> #1 (rtnl_mutex){+.+.+.}:
[   22.991449]        [<ffffffff810dfdd9>] __lock_acquire+0xb19/0x1260
[   22.991477]        [<ffffffff810e0d12>] lock_acquire+0xa2/0x1f0
[   22.991501]        [<ffffffff81673659>] mutex_lock_nested+0x89/0x4f0
[   22.991529]        [<ffffffff815392b7>] rtnl_lock+0x17/0x20
[   22.991552]        [<ffffffff815230b2>] netdev_notify_peers+0x12/0x30
[   22.991579]        [<ffffffffa0340212>] netvsc_send_garp+0x22/0x30 [hv_netvsc]
[   22.991610]        [<ffffffff8108d251>] process_one_work+0x211/0x6e0
[   22.991637]        [<ffffffff8108d83b>] worker_thread+0x11b/0x3a0
[   22.991663]        [<ffffffff81095e5d>] kthread+0xed/0x100
[   22.991686]        [<ffffffff81681c6c>] ret_from_fork+0x7c/0xb0
[   22.991715]
-> #0 ((&(&net_device_ctx->dwork)->work)){+.+.+.}:
[   22.991715]        [<ffffffff810de817>] check_prevs_add+0x967/0x970
[   22.991715]        [<ffffffff810dfdd9>] __lock_acquire+0xb19/0x1260
[   22.991715]        [<ffffffff810e0d12>] lock_acquire+0xa2/0x1f0
[   22.991715]        [<ffffffff8108afde>] flush_work+0x4e/0x2e0
[   22.991715]        [<ffffffff8108e1b5>] __cancel_work_timer+0x95/0x130
[   22.991715]        [<ffffffff8108e303>] cancel_delayed_work_sync+0x13/0x20
[   22.991715]        [<ffffffffa03404e4>] netvsc_change_mtu+0x84/0x200 [hv_netvsc]
[   22.991715]        [<ffffffff815233d4>] dev_set_mtu+0x34/0x80
[   22.991715]        [<ffffffff8153bc2a>] do_setlink+0x23a/0xa00
[   22.991715]        [<ffffffff8153d054>] rtnl_newlink+0x394/0x5e0
[   22.991715]        [<ffffffff81539eac>] rtnetlink_rcv_msg+0x9c/0x260
[   22.991715]        [<ffffffff8155cdd9>] netlink_rcv_skb+0xa9/0xc0
[   22.991715]        [<ffffffff81539dfa>] rtnetlink_rcv+0x2a/0x40
[   22.991715]        [<ffffffff8155c41d>] netlink_unicast+0xdd/0x190
[   22.991715]        [<ffffffff8155c807>] netlink_sendmsg+0x337/0x750
[   22.991715]        [<ffffffff8150d219>] sock_sendmsg+0x99/0xd0
[   22.991715]        [<ffffffff8150d63e>] ___sys_sendmsg+0x39e/0x3b0
[   22.991715]        [<ffffffff8150eba2>] __sys_sendmsg+0x42/0x80
[   22.991715]        [<ffffffff8150ebf2>] SyS_sendmsg+0x12/0x20
[   22.991715]        [<ffffffff81681d19>] system_call_fastpath+0x16/0x1b

This is because we hold the rtnl_lock() before ndo_change_mtu() and try to flush
the work in netvsc_change_mtu(), in the mean time, netdev_notify_peers() may be
called from worker and also trying to hold the rtnl_lock. This will lead the
flush won't succeed forever. Solve this by not canceling and flushing the work,
this is safe because the transmission done by NETDEV_NOTIFY_PEERS was
synchronized with the netif_tx_disable() called by netvsc_change_mtu().
Reported-by: NYaju Cao <yacao@redhat.com>
Tested-by: NYaju Cao <yacao@redhat.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Acked-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Veaceslav Falico <vfalico@redhat.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Paul Mackerras <paulus@samba.org>
CC: Ian Campbell <ian.campbell@citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: NWei Liu <wei.liu2@citrix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove HV_DRV_VERSION, it has no meaning for upstream drivers.

Initially it was supposed to show the "Linux Integration Services"
version, now it is not in sync anymore with the out-of-tree drivers
available from the MSFT website.

The only place where a version string is still required is the KVP
command "IntegrationServicesVersion" which is handled by
tools/hv/hv_kvp_daemon.c. To satisfy such KVP request from the host pass
the current string to the daemon during KVP userland registration.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

SG mode is not currently supported by netvsc, so remove this flag for now.
Otherwise, it will be unconditionally enabled by commit ec5f0615
    "Kill link between CSUM and SG features"
Previously, the SG feature is disabled because CSUM is not set here.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We should call __vlan_hwaccel_put_tag() only if the packet
comes from vlan, otherwise VLAN_TAG_PRESENT will always be
added.
Reported-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the recent addition of 8021AD, we need to set the new field vlan_proto in
sk_buff. Otherwise, it will trigger BUG() call in vlan_proto_idx().

This patch fixes the problem.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixed: warning: cast from pointer to integer of different size

The Hyper-V hosts always use 64 bit request id. The guests can have 32 or 64
bit pointers which equal to the ulong type size. So we cast it to ulong type.
And, assigning 32bit integer to 64 bit variable works fine.

The VMBus returns the same id in the completion packet. But the value has no
effect on the host side.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
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>