Ido Schimmel says:

====================
mlxsw: Support DSCP prioritization and rewrite

Petr says:

On ingress, a network device such as a switch assigns to packets
priority based on various criteria. Common options include interpreting
PCP and DSCP fields according to user configuration. When a packet
egresses the switch, a reverse process may rewrite PCP and/or DSCP
headers according to packet priority.

So far, mlxsw has supported prioritization based on PCP (802.1p priority
tag). This patch set introduces support for prioritization based on
DSCP, and DSCP rewrite.

To configure the DSCP-to-priority maps, the user is expected to invoke
ieee_setapp and ieee_delapp DCBNL ops, e.g. by using lldptool:

To decide whether or not to pay attention to DSCP values, the Spectrum
switch recognize a per-port configuration of trust level. Until the
first APP rule is added for a given port, this port's trust level stays
at PCP, meaning that PCP is used for packet prioritization. With the
first DSCP APP rule, the port is configured to trust DSCP instead, and
it stays there until all DSCP APP rules are removed again.

Besides the DSCP (value 5) selector, another selector that plays into
packet prioritization is Ethernet type (value 1) with PID of 0. Such APP
entries denote default priority[1]:

With this patch set, mlxsw uses these values to configure priority for
DSCP values not explicitly specified in DSCP APP map. In the future we
expect to also use this to configure default port priority for untagged
packets.

Access to DSCP-to-priority map, priority-to-DSCP map, and default
priority for a port is exposed through three new DCB helpers. Like the
already-existing dcb_ieee_getapp_mask() helper, these helpers operate in
terms of bitmaps, to support the arbitrary M:N mapping that the APP
rules allow. Such interface presents all the relevant information from
the APP database without necessitating exposition of iterators, locking
or other complex primitives. It is up to the driver to then digest the
mapping in a way that the device supports. In this patch set, mlxsw
resolves conflicts by favoring higher-numbered DSCP values and
priorities.

In this patchset:

- Patch #1 fixes a bug in DCB APP database management.
- Patch #2 adds the getters described above.
- Patches #3-#6 add Spectrum configuration registers.
- Patch #7 adds the mlxsw logic that configures the device according to
  APP rules.
- Patch #8 adds a self-test. The test is added to the subdirectory
  drivers/net/mlxsw. Even though it's not particularly specific to
  mlxsw, it's not suitable for running on soft devices (which don't
  support the ieee_getapp et.al.), and thus isn't a good fit for the
  general net/forwarding directory.

[1] 802.1Q-2014, Table D-9
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a test that exercises the new code. Send DSCP-tagged packets, and
observe how they are prioritized in the switch and the DSCP is updated
on egress again.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The APP TLVs are used for communicating priority-to-protocol ID maps for
a given netdevice. Support the following APP TLVs:

- DSCP (selector 5) to configure priority-to-DSCP code point maps. Use
  these maps to configure packet priority on ingress, and DSCP code
  point rewrite on egress.

- Default priority (selector 1, PID 0) to configure priority for the
  DSCP code points that don't have one assigned by the DSCP selector. In
  future this could also be used for assigning default port priority
  when a packet arrives without DSCP tagging.

Besides setting up the maps themselves, also configure port trust level
and rewrite bits.

Port trust level determines whether, for a packet arriving through a
certain port, the priority should be determined based on PCP or DSCP
header fields. So far, mlxsw kept the device default of trust-PCP. Now,
as soon as the first DSCP APP TLV is configured, switch to trust-DSCP.
Only when all DSCP APP TLVs are removed, switch back to trust-PCP again.
Note that the default priority APP TLV doesn't impact the trust level
configuration.

Rewrite bits determine whether DSCP and PCP fields of egressing packets
should be updated according to switch priority. When port trust is
switched to DSCP, enable rewrite of DSCP field.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This register controls mapping from Priority to DSCP for purposes of
rewrite. Note that rewrite happens as the packet is transmitted provided
that the DSCP rewrite bit is enabled for the packet.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This register configures the rewrite enable (whether PCP or DSCP value
in packet should be updated according to packet priority) per receive
port.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The QPTS register controls the port policy to calculate the switch
priority and packet color based on incoming packet fields.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The QPDPM register controls the mapping from DSCP field to Switch
Priority for IP packets.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On ingress, a network device such as a switch assigns to packets
priority based on various criteria. Common options include interpreting
PCP and DSCP fields according to user configuration. When a packet
egresses the switch, a reverse process may rewrite PCP and/or DSCP
values according to packet priority.

The following three functions support a) obtaining a DSCP-to-priority
map or vice versa, and b) finding default-priority entries in APP
database.

The DCB subsystem supports for APP entries a very generous M:N mapping
between priorities and protocol identifiers. Understandably,
several (say) DSCP values can map to the same priority. But this
asymmetry holds the other way around as well--one priority can map to
several DSCP values. For this reason, the following functions operate in
terms of bitmaps, with ones in positions that match some APP entry.

- dcb_ieee_getapp_dscp_prio_mask_map() to compute for a given netdevice
  a map of DSCP-to-priority-mask, which gives for each DSCP value a
  bitmap of priorities related to that DSCP value by APP, along the
  lines of dcb_ieee_getapp_mask().

- dcb_ieee_getapp_prio_dscp_mask_map() similarly to compute for a given
  netdevice a map from priorities to a bitmap of DSCPs.

- dcb_ieee_getapp_default_prio_mask() which finds all default-priority
  rules for a given port in APP database, and returns a mask of
  priorities allowed by these default-priority rules.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The function dcb_app_lookup walks the list of specified DCB APP entries,
looking for one that matches a given criteria: ifindex, selector,
protocol ID and optionally also priority. The "don't care" value for
priority is set to 0, because that priority has not been allowed under
CEE regime, which predates the IEEE standardization.

Under IEEE, 0 is a valid priority number. But because dcb_app_lookup
considers zero a wild card, attempts to add an APP entry with priority 0
fail when other entries exist for a given ifindex / selector / PID
triplet.

Fix by changing the wild-card value to -1.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In case a chain is empty and not explicitly created by a user,
such chain should not exist. The only exception is if there is
an action "goto chain" pointing to it. In that case, don't show the
chain in the dump. Track the chain references held by actions and
use them to find out if a chain should or should not be shown
in chain dump.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2018-07-27

1) Extend the output_mark to also support the input direction
   and masking the mark values before applying to the skb.

2) Add a new lookup key for the upcomming xfrm interfaces.

3) Extend the xfrm lookups to match xfrm interface IDs.

4) Add virtual xfrm interfaces. The purpose of these interfaces
   is to overcome the design limitations that the existing
   VTI devices have.

  The main limitations that we see with the current VTI are the
  following:

  VTI interfaces are L3 tunnels with configurable endpoints.
  For xfrm, the tunnel endpoint are already determined by the SA.
  So the VTI tunnel endpoints must be either the same as on the
  SA or wildcards. In case VTI tunnel endpoints are same as on
  the SA, we get a one to one correlation between the SA and
  the tunnel. So each SA needs its own tunnel interface.

  On the other hand, we can have only one VTI tunnel with
  wildcard src/dst tunnel endpoints in the system because the
  lookup is based on the tunnel endpoints. The existing tunnel
  lookup won't work with multiple tunnels with wildcard
  tunnel endpoints. Some usecases require more than on
  VTI tunnel of this type, for example if somebody has multiple
  namespaces and every namespace requires such a VTI.

  VTI needs separate interfaces for IPv4 and IPv6 tunnels.
  So when routing to a VTI, we have to know to which address
  family this traffic class is going to be encapsulated.
  This is a lmitation because it makes routing more complex
  and it is not always possible to know what happens behind the
  VTI, e.g. when the VTI is move to some namespace.

  VTI works just with tunnel mode SAs. We need generic interfaces
  that ensures transfomation, regardless of the xfrm mode and
  the encapsulated address family.

  VTI is configured with a combination GRE keys and xfrm marks.
  With this we have to deal with some extra cases in the generic
  tunnel lookup because the GRE keys on the VTI are actually
  not GRE keys, the GRE keys were just reused for something else.
  All extensions to the VTI interfaces would require to add
  even more complexity to the generic tunnel lookup.

  So to overcome this, we developed xfrm interfaces with the
  following design goal:

  It should be possible to tunnel IPv4 and IPv6 through the same
  interface.

  No limitation on xfrm mode (tunnel, transport and beet).

  Should be a generic virtual interface that ensures IPsec
  transformation, no need to know what happens behind the
  interface.

  Interfaces should be configured with a new key that must match a
  new policy/SA lookup key.

  The lookup logic should stay in the xfrm codebase, no need to
  change or extend generic routing and tunnel lookups.

  Should be possible to use IPsec hardware offloads of the underlying
  interface.

5) Remove xfrm pcpu policy cache. This was added after the flowcache
   removal, but it turned out to make things even worse.
   From Florian Westphal.

6) Allow to update the set mark on SA updates.
   From Nathan Harold.

7) Convert some timestamps to time64_t.
   From Arnd Bergmann.

8) Don't check the offload_handle in xfrm code,
   it is an opaque data cookie for the driver.
   From Shannon Nelson.

9) Remove xfrmi interface ID from flowi. After this pach
   no generic code is touched anymore to do xfrm interface
   lookups. From Benedict Wong.

10) Allow to update the xfrm interface ID on SA updates.
    From Nathan Harold.

11) Don't pass zero to ERR_PTR() in xfrm_resolve_and_create_bundle.
    From YueHaibing.

12) Return more detailed errors on xfrm interface creation.
    From Benedict Wong.

13) Use PTR_ERR_OR_ZERO instead of IS_ERR + PTR_ERR.
    From the kbuild test robot.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/xfrm/xfrm_interface.c:692:1-3: WARNING: PTR_ERR_OR_ZERO can be used

 Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci

Fixes: 44e2b838 ("xfrm: Return detailed errors from xfrmi_newlink")
CC: Benedict Wong <benedictwong@google.com>
Signed-off-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

Saeed Mahameed says:

====================
mlx5e-updates-2018-07-26 (XDP redirect)

This series from Tariq adds the support for device-out XDP redirect.

Start with a simple RX and XDP cleanups:
- Replace call to MPWQE free with dealloc in interface down flow
- Do not recycle RX pages in interface down flow
- Gather all XDP pre-requisite checks in a single function
- Restrict the combination of large MTU and XDP

Since now XDP logic is going to be called from TX side as well,
generic XDP TX logic is not RX only anymore, for that Tariq creates
a new xdp.c file and moves XDP related code into it, and generalizes
the code to support XDP TX for XDP redirect, such as the xdp tx sq
structures and xdp counters.

XDP redirect support:
Add implementation for the ndo_xdp_xmit callback.

Dedicate a new set of XDP-SQ instances to satisfy the XDP_REDIRECT
requests.  These instances are totally separated from the existing
XDP-SQ objects that satisfy local XDP_TX actions.

Performance tests:

xdp_redirect_map from ConnectX-5 to ConnectX-5.
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz
Packet-rate of 64B packets.

Single queue: 7 Mpps.
Multi queue: 55 Mpps.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The root directories of netdevsim should only be used by the core
to create per-device subdirectories, so limit their visibility to
the core file.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tobin C. Harding says:

====================
docs: net: Convert netdev-FAQ to RST

Jon answered all the tree questions on v1 so if you will please take
this through your tree that would be awesome.

v2:
 - Fix typo 'canonical_path_format' (thanks Edward)
 - Add patch fixing references netdev-FAQ
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

File 'Documentation/networking/netdev-FAQ.txt' has been converted to RST
format.  We should update all links/references to point to the new file.

Update references to netdev-FAQ
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

Preferred kernel docs format is now restructured text.  Convert
netdev-FAQ.txt to restructured text.

 - Add SPDX license identifier.

 - Change file heading 'Information you need to know about netdev' to
  'netdev FAQ' to better suit displayed index (in HTML).

 - Change question/answer layout to suit rst.  Copy format in
   Documentation/bpf/bpf_devel_QA.rst

 - Fix indentation of code snippets

 - If multiple consecutive URLs appear put them in a list (to maintain
  whitespace).

 - Use uniform spelling of 'bug fix' throughout document (not bugfix or
   bug-fix).

 - Add double back ticks to 'net' and 'net-next' when referring to the
   trees.

 - Use rst references for Documentation/ links.

 - Add rst label 'netdev-FAQ' for referencing by other docs files.

 - Remove stale entry from Documentation/networking/00-INDEX
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

In preparation to convert Documentation/network/netdev-FAQ.rst to
restructured text format.  We would like to be able to reference 'the
canonical patch format' section.

Add rest label: 'the_canonical_patch_format'.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

starfire_init_one() is never called in atomic context.
It calls mdelay() to busily wait, which is not necessary.
mdelay() can be replaced with msleep().

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hisax_cs_new() and hisax_cs_setup() are never called in atomic context.
They call kmalloc() and kzalloc() with GFP_ATOMIC, which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

init_PStack() is never called in atomic context.
It calls kmalloc() with GFP_ATOMIC, which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nj_probe() is never called in atomic context.
It calls kzalloc() with GFP_ATOMIC, which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hfc_probe() is never called in atomic context.
It calls kzalloc() with GFP_ATOMIC, which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hns_dsaf_roce_reset is exported and used in hns_roce_hw_v1.c
In commit 336a443b ("net: hns: Make many functions static") I make
it static wrongly.

drivers/infiniband/hw/hns/hns_roce_hw_v1.o: In function `hns_roce_v1_reset':
hns_roce_hw_v1.c:(.text+0x37ac): undefined reference to `hns_dsaf_roce_reset'
hns_roce_hw_v1.c:(.text+0x37cc): undefined reference to `hns_dsaf_roce_reset'

Fixes: 336a443b ("net: hns: Make many functions static")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use designated function mlx5e_dma_get() to get
the mlx5e_sq_dma object to be pushed into fifo.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Pointers in DB are static, move them to read-only area so they
do not share a cacheline with fields modified in datapath.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

A loaded XDP program might write to the xdp_frame data area,
prefetchw() it to avoid a potential cache miss.

Performance tests:
ConnectX-5, XDP_TX packet rate, single ring.
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz

Before: 13,172,976 pps
After:  13,456,248 pps
2% gain.

Fixes: 22f45398 ("net/mlx5e: Support XDP over Striding RQ")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Add implementation for the ndo_xdp_xmit callback.

Dedicate a new set of XDP-SQ instances to satisfy the XDP_REDIRECT
requests.  These instances are totally separated from the existing
XDP-SQ objects that satisfy local XDP_TX actions.

Performance tests:

xdp_redirect_map from ConnectX-5 to ConnectX-5.
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz
Packet-rate of 64B packets.

Single queue: 7 Mpps.
Multi queue: 55 Mpps.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

In the downstream patch that adds support to XDP_REDIRECT-out,
the XDP xmit frame function doesn't share the same run context as
the NAPI that polls the XDP-SQ completion queue.

Hence, need to re-order the XDP-SQ fields to avoid cacheline
false-sharing.

Take redirect_flush and doorbell out of DB, into separated
cachelines.

Add a cacheline breaker within the stats struct.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Separate the XDP counters into two sets:
(1) One set reside in the RQ stats, and they monitor XDP stats
in the RQ side.
(2) Another set is per XDP-SQ, and they monitor XDP stats that
are related to XDP transmit flow.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Convert the XDP xmit functions to use the generic xdp_frame API
in XDP_TX flow.
Same functions will be used later in this series to transmit
the XDP redirect-out packets as well.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Add per-ring and total stats for received packets that
goes into XDP redirection.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Take XDP code out of the general EN header and RX file into
new XDP files.

Currently, XDP-SQ resides only within an RQ and used from a
single flow (XDP_TX) triggered upon RX completions.
In a downstream patch, additional type of XDP-SQ instances will be
presented and used for the XDP_REDIRECT flow, totally unrelated to
the RX context.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Add checks in control path upon an MTU change or an XDP program set,
to prevent reaching cases where large MTU and XDP are set simultaneously.

This is to make sure we allow XDP only with the linear RX memory scheme,
i.e. a received packet is not scattered to different pages.
Change mlx5e_rx_get_linear_frag_sz() accordingly, so that we make sure
the XDP configuration can really be set, instead of assuming that it is.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Dedicate a function to all checks done when setting an XDP program.
Take indications from priv instead of netdev features.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Keep all page-pool recycle calls within NAPI context.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

No need to expose the MPWQE free function to control path.
The dealloc function already exposed, use it.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Jeff Kirsher says:

====================
10GbE Intel Wired LAN Driver Updates 2018-07-26

This series contains updates to ixgbe and igb.

Tony fixes ixgbe to add checks to ensure jumbo frames or LRO get enabled
after an XDP program is loaded.

Shannon Nelson adds the missing security configuration registers to the
ixgbe register dump, which will help in debugging.

Christian Grönke fixes an issue in igb that occurs on SGMII based SPF
mdoules, by reverting changes from 2 previous patches.  The issue was
that initialization would fail on the fore mentioned modules because the
driver would try to reset the PHY before obtaining the PHY address of
the SGMII attached PHY.

Venkatesh Srinivas replaces wmb() with dma_wmb() for doorbell writes,
which avoids SFENCEs before the doorbell writes.

Alex cleans up and refactors ixgbe Tx/Rx shutdown to reduce time needed
to stop the device.  The code refactor allows us to take the completion
time into account when disabling queues, so that on some platforms with
higher completion times, would not result in receive queues disabled
messages.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Once user manually deletes the chain using "chain del", the chain cannot
be marked as explicitly created anymore.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Fixes: 32a4f5ec ("net: sched: introduce chain object to uapi")
Signed-off-by: David S. Miller <davem@davemloft.net>

The zerocopy path ultimately calls iov_iter_get_pages, which defines the
step function for ITER_KVECs as simply, return -EFAULT. Taking the
non-zerocopy path for ITER_KVECs avoids the unnecessary fallback.

See https://lore.kernel.org/lkml/20150401023311.GL29656@ZenIV.linux.org.uk/T/#u
for a discussion of why zerocopy for vmalloc data is not a good idea.

Discovered while testing NBD traffic encrypted with ktls.

Fixes: c46234eb ("tls: RX path for ktls")
Signed-off-by: Doron Roberts-Kedes <doronrk@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>