Vlan tagged packets are getting dropped when used with DPDK that uses
the AF_PACKET interface on a hyperV guest.

The packet layer uses the tpacket interface to communicate the vlans
information to the upper layers. On Rx path, these drivers can read the
vlan info from the tpacket header but on the Tx path, this information
is still within the packet frame and requires the paravirtual drivers to
push this back into the NDIS header which is then used by the host OS to
form the packet.

This transition from the packet frame to NDIS header is currently missing
hence causing the host OS to drop the all vlan tagged packets sent by
the drivers that use AF_PACKET (ETH_P_ALL) such as DPDK.

Here is an overview of the changes in the vlan header in the packet path:

The RX path (userspace handles everything):
  1. RX VLAN packet is stripped by HOST OS and placed in NDIS header
  2. Guest Kernel RX hv_netvsc packets and moves VLAN info from NDIS
     header into kernel SKB
  3. Kernel shares packets with user space application with PACKET_MMAP.
     The SKB VLAN info is copied to tpacket layer and indication set
     TP_STATUS_VLAN_VALID.
  4. The user space application will re-insert the VLAN info into the frame

The TX path:
  1. The user space application has the VLAN info in the frame.
  2. Guest kernel gets packets from the application with PACKET_MMAP.
  3. The kernel later sends the frame to the hv_netvsc driver. The only way
     to send VLANs is when the SKB is setup & the VLAN is stripped from the
     frame.
  4. TX VLAN is re-inserted by HOST OS based on the NDIS header. If it sees
     a VLAN in the frame the packet is dropped.

Cc: xe-linux-external@cisco.com
Cc: Sriram Krishnan <srirakr2@cisco.com>
Signed-off-by: NSriram Krishnan <srirakr2@cisco.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support of XDP in native mode for hv_netvsc driver, and
transparently sets the XDP program on the associated VF NIC as well.

Setting / unsetting XDP program on synthetic NIC (netvsc) propagates to
VF NIC automatically. Setting / unsetting XDP program on VF NIC directly
is not recommended, also not propagated to synthetic NIC, and may be
overwritten by setting of synthetic NIC.

The Azure/Hyper-V synthetic NIC receive buffer doesn't provide headroom
for XDP. We thought about re-use the RNDIS header space, but it's too
small. So we decided to copy the packets to a page buffer for XDP. And,
most of our VMs on Azure have Accelerated  Network (SRIOV) enabled, so
most of the packets run on VF NIC. The synthetic NIC is considered as a
fallback data-path. So the data copy on netvsc won't impact performance
significantly.

XDP program cannot run with LRO (RSC) enabled, so you need to disable LRO
before running XDP:
        ethtool -K eth0 lro off

XDP actions not yet supported:
        XDP_REDIRECT
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In existing code, the receive indirection table, rx_table, is in
struct rndis_device, which will be reset when changing MTU, ringparam,
etc. User configured receive indirection table values will be lost.

To fix this, move rx_table to struct net_device_context, and check
netif_is_rxfh_configured(), so rx_table will be set to default only
if no user configured value.

Fixes: ff4a4419 ("netvsc: allow get/set of RSS indirection table")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The recording of RSS hash should be controlled by NETIF_F_RXHASH.

Fixes: 1fac7ca4 ("hv_netvsc: record hardware hash in skb")
Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

To reach the data region, the existing code adds offset in struct
nvsp_5_send_indirect_table on the beginning of this struct. But the
offset should be based on the beginning of its container,
struct nvsp_message. This bug causes the first table entry missing,
and adds an extra zero from the zero pad after the data region.
This can put extra burden on the channel 0.

So, correct the offset usage. Also add a boundary check to ensure
not reading beyond data region.

Fixes: 5b54dac8 ("hyperv: Add support for virtual Receive Side Scaling (vRSS)")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The existing netvsc_detach() and netvsc_attach() APIs make it easy to
implement the suspend/resume callbacks.
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

Since RSS hash is available from the host, record it in
the skb.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In a previous patch, the NETIF_F_SG was missing after the code changes.
That caused the SG feature to be "fixed". This patch includes it into
hw_features, so it is tunable again.

Fixes: 23312a3b ("netvsc: negotiate checksum and segmentation parameters")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Reviewed-by: NSteve Winslow <swinslow@gmail.com>
Reviewed-by: NRichard Fontana <rfontana@redhat.com>
Reviewed-by: NAlexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After queue stopped, the wakeup mechanism may wake it up again
when ring buffer usage is lower than a threshold. This may cause
send path panic on NULL pointer when we stopped all tx queues in
netvsc_detach and start removing the netvsc device.

This patch fix it by adding a tx_disable flag to prevent unwanted
queue wakeup.

Fixes: 7b2ee50c ("hv_netvsc: common detach logic")
Reported-by: NMohammed Gamal <mgamal@redhat.com>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix all typos from hyperv netvsc code comments.
Signed-off-by: NAdrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Alessandro Pilotti" <apilotti@cloudbasesolutions.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

Changing mtu, channels, or buffer sizes ops call to netvsc_attach(),
rndis_set_subchannel(), which always reset the hash key to default
value. That will override hash key changed previously. This patch
fixes the problem by save the hash key, then restore it when we re-
add the netvsc device.

Fixes: ff4a4419 ("netvsc: allow get/set of RSS indirection table")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
[sl: fix up subject line]
Signed-off-by: NSasha Levin <sashal@kernel.org>

This patch adds the handler for LRO setting change, so that a user
can use ethtool command to enable / disable LRO feature.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

LRO/RSC in the vSwitch is a feature available in Windows Server 2019
hosts and later. It reduces the per packet processing overhead by
coalescing multiple TCP segments when possible. This patch adds netvsc
driver support for this feature.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements following ethtool stats fields for netvsc:
cpu<n>_tx/rx_packets/bytes
cpu<n>_vf_tx/rx_packets/bytes

Corresponding per-cpu counters already exist in current code. Exposing
these counters will help troubleshooting performance issues.

for_each_present_cpu() was used instead of for_each_possible_cpu().
for_each_possible_cpu() would create very long and useless output.
It is still being used for internal buffer, but not for ethtool
output.

There could be an overflow if cpu was added between ethtool
call netvsc_get_sset_count() and netvsc_get_ethtool_stats() and
netvsc_get_strings(). (still safe if cpu was removed)
ethtool makes these three function calls separately.
As long as we use ethtool, I can't see any clean solution.

Currently and in foreseeable short term, Hyper-V doesn't support
cpu hot-plug. Plus, ethtool is for admin use. Unlikely the admin
would perform such combo operations.

Changes in v2:
  - Remove cpp style comment
  - Resubmit after freeze

Changes in v3:
  - Reimplemented with kvmalloc instead of alloc_percpu

Changes in v4:
  - Fixed inconsistent array size
  - Use kvmalloc_array instead of kvmalloc
Signed-off-by: NYidong Ren <yidren@microsoft.com>
Reviewed-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When doing device hotplug the sub channel must be async to avoid
deadlock issues because device is discovered in softirq context.

When doing changes to MTU and number of channels, the setup
must be synchronous to avoid races such as when MTU and device
settings are done in a single ip command.
Reported-by: NThomas Walker <Thomas.Walker@twosigma.com>
Fixes: 8195b139 ("hv_netvsc: fix deadlock on hotplug")
Fixes: 732e4985 ("netvsc: fix race on sub channel creation")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These fields in struct ndis_ipsecv2_offload and struct ndis_rsc_offload
are one byte according to the specs. This patch defines them with the
right size. These structs are not in use right now, but will be used soon.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When finding the parent netvsc device, the search needs to be across
all netvsc device instances (independent of network namespace).

Find parent device of VF using upper_dev_get routine which
searches only adjacent list.

Fixes: e8ff40d4 ("hv_netvsc: improve VF device matching")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>

netns aware byref
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The callback model of handling network failover is not suitable
in the current form.
  1. It was merged without addressing all the review feedback.
  2. It was merged without approval of any of the netvsc maintainers.
  3. Design discussion on how to handle PV/VF fallback is still
     not complete.
  4. IMHO the code model using callbacks is trying to make
     something common which isn't.

Revert the netvsc specific changes for now. Does not impact ongoing
development of failover model for virtio.
Revisit this after a simpler library based failover kernel
routines are extracted.

This reverts
commit 9c6ffbac ("hv_netvsc: fix error return code in netvsc_probe()")
and
commit 1ff78076 ("netvsc: refactor notifier/event handling code to use the failover framework")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the registration/notification framework supported by the generic
failover infrastructure.
Signed-off-by: NSridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix simple misspelling kashkey_offset should be hashkey_offset.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the NetVSP v6 and 6.1 message structures, and includes
these versions into NetVSC/NetVSP version negotiation process.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In Vmbus, we have defined a function to calculate available ring buffer
percentage to write.

Use that function and remove netvsc's private version.

[mkp: typo]
Signed-off-by: NLong Li <longli@microsoft.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch adds range checking for rx packet offset and length.
It may only happen if there is a host side bug.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make common function for detaching internals of device
during changes to MTU and RSS. Make sure no more packets
are transmitted and all packets have been received before
doing device teardown.

Change the wait logic to be common and use usleep_range().

Changes transmit enabling logic so that transmit queues are disabled
during the period when lower device is being changed. And enabled
only after sub channels are setup. This avoids issue where it could
be that a packet was being sent while subchannel was not initialized.

Fixes: 8195b139 ("hv_netvsc: fix deadlock on hotplug")
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The netvsc driver can get repeated calls to netvsc_rx_mode during
network setup; each of these calls ends up scheduling the lower
layers to update tha packet filter. This update requires an
request/response to the host. So avoid doing this if we already
know that the correct packet filter value is set.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the transmit queue is known full, then don't keep aggregating
data. And the cp_partial flag which indicates that the current
aggregation buffer is full can be folded in to avoid more
conditionals.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is only ever a single instance of network device object
referencing the internal rndis object. Therefore the open_cnt atomic
is not necessary.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The netvsc_receive_callback function was using RCU to find the
appropriate underlying netvsc_device. Since calling function already
had that pointer, this was unnecessary.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The caller (netvsc_receive) already has the net device pointer,
and should just pass that to functions rather than the hyperv device.
This eliminates several impossible error paths in the process.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When skb can not be allocated, update ethtool statisitics
rather than rx_dropped which is intended for netif_receive.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The values were not computed correctly. There are no significant
visible impact, though.

The intended size of RX buffer is 16 MB, and the default slot size is 1728.
So, NETVSC_DEFAULT_RX should be 16*1024*1024 / 1728 = 9709.

The intended size of TX buffer is 1 MB, and the slot size is 6144.
So, NETVSC_DEFAULT_TX should be 1024*1024 / 6144 = 170.

The patch puts the formula directly into the macro, and moves them to
hyperv_net.h, together with related macros.

Fixes: 5023a6db ("netvsc: increase default receive buffer size")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The max should be 31 MB on host with NVSP version > 2.

On legacy hosts (NVSP version <=2) only 15 MB receive buffer is allowed,
otherwise the buffer request will be rejected by the host, resulting
vNIC not coming up.

The NVSP version is only available after negotiation. So, we add the
limit checking for legacy hosts in netvsc_init_buf().

Fixes: 5023a6db ("netvsc: increase default receive buffer size")
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Every packet sent checks the available ring space. The calculation
can be sped up by using reciprocal divide which is multiplication.

Since ring_size can only be configured by module parameter, so it doesn't
have to be passed around everywhere. Also it should be unsigned
since it is number of pages.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rndis_filter_device_add() is called both from netvsc_probe() when we
initially create the device and from set channels/mtu/ringparam
routines where we basically remove the device and add it back.

hw_features is reset in rndis_filter_device_add() and filled with
host data. However, we lose all additional flags which are set outside
of the driver, e.g. register_netdevice() adds NETIF_F_SOFT_FEATURES and
many others.

Unfortunately, calls to rndis_{query_hwcaps(), _set_offload_params()}
calls cannot be avoided on every RNDIS reset: host expects us to set
required features explicitly. Moreover, in theory hardware capabilities
can change and we need to reflect the change in hw_features.

Reset net->hw_features bits according to host data in
rndis_netdev_set_hwcaps(), clear corresponding feature bits
from net->features in case some features went missing (will never happen
in real life I guess but let's be consistent).
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simplify the variable name: tx_send_table
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename this variable because it is the Receive indirection
table.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This simplifies the logic and make it easier to add more
options.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Report the numbers of events for stop_queue and wake_queue in
ethtool stats.

Example:
ethtool -S eth0
NIC statistics:
	...
	stop_queue: 7
	wake_queue: 7
	...
Signed-off-by: NSimon Xiao <sixiao@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>