When packet encapsulation is in use, the MTU needs to be reduced for
headroom reservation.
The existing code takes the updated MTU value only from the host side.
But vSwitch extensions, such as Open vSwitch, require the flexibility
to change the MTU to different values from within a guest during the
lifecycle of a vNIC, when the encapsulation protocol is changed. The
patch supports this kind of MTU changes.
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>

The current algorithm for deciding on the number of VRSS channels is
not optimal since we open up the min of number of CPUs online and the
number of VRSS channels the host is offering. So on a 32 VCPU guest
we could potentially open 32 VRSS subchannels. Experimentation has
shown that it is best to limit the number of VRSS channels to the number
of CPUs within a NUMA node.

Here is the new algorithm for deciding on the number of sub-channels we
would open up:
        1) Pick the minimum of what the host is offering and what the driver
           in the guest is specifying as the default value.
        2) Pick the minimum of (1) and the numbers of CPUs in the NUMA
           node the primary channel is bound to.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently the struct netvsc_stats has a member s_sync
of type u64_stats_sync.
This definition will break kernel build as the macro
netdev_alloc_pcpu_stats requires this member name to be syncp.
(see netdev_alloc_pcpu_stats definition in ./include/linux/netdevice.h)

This patch changes netvsc_stats's member name from s_sync to syncp to fix
the build break.
Signed-off-by: NSimon Xiao <sixiao@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current code does not lock anything when calculating the TX and RX stats.
As a result, the RX and TX data reported by ifconfig are not accuracy in a
system with high network throughput and multiple CPUs (in my test,
RX/TX = 83% between 2 HyperV VM nodes which have 8 vCPUs and 40G Ethernet).

This patch fixed the above issue by using per_cpu stats.
netvsc_get_stats64() summarizes TX and RX data by iterating over all CPUs
to get their respective stats.

This v2 patch addressed David's comments on the cleanup path when
netdev_alloc_pcpu_stats() failed.
Signed-off-by: NSimon Xiao <sixiao@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit b08cc791 eliminated memory
allocation in the packet send path:

    "hv_netvsc: Eliminate memory allocation in the packet send path

    The network protocol used to communicate with the host is the remote ndis (rndis)
    protocol. We need to decorate each outgoing packet with a rndis header and
    additional rndis state (rndis per-packet state). To manage this state, we
    currently allocate memory in the transmit path. Eliminate this allocation by
    requesting additional head room in the skb."

This commit introduced a bug since it did not account for the case if the skb
was cloned. Fix this bug.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Tested-by: NDexuan Cui <decui@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1. Introduce netif-msg to netvsc to control debug logging output
and keep msg_enable in netvsc_device_context so that it is
kept persistently.
2. Only call dump_rndis_message() when NETIF_MSG_RX_ERR or above
is specified in netvsc module debug param.
In non-debug mode, in current code, dump_rndis_message() will not
dump anything but it still initialize some local variables and
process the switch logic which is unnecessary, especially in
high network throughput situation.
Signed-off-by: NSimon Xiao <sixiao@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If remaining space in a send buffer slot is too small for the whole message,
we only copy the RNDIS header and PPI data into send buffer, so we can batch
one more packet each time. It reduces the vmbus per-message overhead.
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>

In netvsc_start_xmit() we can handle packets which are scattered around not
more than MAX_PAGE_BUFFER_COUNT-2 pages. It is, however, easy to create a
packet which is not big in size but occupies more pages (e.g. if it uses frags
on compound pages boundaries). When we drop such packet it cases sender to try
resending it but in most cases it will try resending the same packet which will
also get dropped, this will cause the particular connection to stick. To solve
the issue we can try linearizing skb.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

... which validly uses dev_kfree_skb_any() instead of dev_kfree_skb().

Setting ret to -EFAULT and -ENOMEM have no real meaning here (we need to set
it to anything but -EAGAIN) as we drop the packet and return NETDEV_TX_OK
anyway.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the two places changed, we now use netvsc_xmit_completion() which properly
frees hv_netvsc_packet in or not in skb headroom.
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>

The sum of RNDIS msg and PPI struct sizes is used in multiple places, so we define
a macro for them.
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>

The network protocol used to communicate with the host is the remote ndis (rndis)
protocol. We need to decorate each outgoing packet with a rndis header and
additional rndis state (rndis per-packet state). To manage this state, we
currently allocate memory in the transmit path. Eliminate this allocation by
requesting additional head room in the skb.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for embedding the rndis state and other packet state into
the skb, cleanup the test for freeing the skb.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With this patch, we can send out multiple RNDIS data packets in one send buffer
slot and one VMBus message. It reduces the overhead associated with VMBus messages.
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 adds support for reporting the actual and maximum combined channels
count of the hv_netvsc driver via 'ethtool --show-channels'.

This required adding 'max_chn' to 'struct netvsc_device', and assigning
it 'rsscap.num_recv_que' in 'rndis_filter_device_add'. Now we can access
the combined maximum channel count via 'struct netvsc_device' in the
ethtool callback.
Signed-off-by: NAndrew Schwartzmeyer <andrew@schwartzmeyer.com>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the host uses packet encapsulation feature, the MTU may be reduced by the
host due to headroom reservation for encapsulation. This patch handles this
new MTU value.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This will allow the workload spreading via vRSS for IPv6.
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>

total_data_buflen is used by netvsc_send() to decide if a packet can be put
into send buffer. It should also include the size of RNDIS message before the
Ethernet frame. Otherwise, a messge with total size bigger than send_section_size
may be copied into the send buffer, and cause data corruption.

[Request to include this patch to the Stable branches]
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>

In case that the IP header has optional field at the end, this patch will
get the port numbers after that field, and compute the hash. The general
parser skb_flow_dissect() is used 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>

After the packet is successfully sent, we should not touch the skb
as it may have been freed. This patch is based on the work done by
Long Li <longli@microsoft.com>.

In this version of the patch I have fixed issues pointed out by David.
David, please queue this up for stable.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Tested-by: NLong Li <longli@microsoft.com>
Tested-by: NSitsofe Wheeler <sitsofe@yahoo.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>

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>

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>

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>

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>

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>