Commit Graph

332 Commits

Author SHA1 Message Date
Marek Marczykowski-Górecki
e8240addd0 Revert "xen-netback: Check for hotplug-status existence before watching"
This reverts commit 2afeec08ab.

The reasoning in the commit was wrong - the code expected to setup the
watch even if 'hotplug-status' didn't exist. In fact, it relied on the
watch being fired the first time - to check if maybe 'hotplug-status' is
already set to 'connected'. Not registering a watch for non-existing
path (which is the case if hotplug script hasn't been executed yet),
made the backend not waiting for the hotplug script to execute. This in
turns, made the netfront think the interface is fully operational, while
in fact it was not (the vif interface on xen-netback side might not be
configured yet).

This was a workaround for 'hotplug-status' erroneously being removed.
But since that is reverted now, the workaround is not necessary either.

More discussion at
https://lore.kernel.org/xen-devel/afedd7cb-a291-e773-8b0d-4db9b291fa98@ipxe.org/T/#u

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Michael Brown <mbrown@fensystems.co.uk>
Link: https://lore.kernel.org/r/20220222001817.2264967-2-marmarek@invisiblethingslab.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-24 08:58:37 -08:00
Marek Marczykowski-Górecki
0f4558ae91 Revert "xen-netback: remove 'hotplug-status' once it has served its purpose"
This reverts commit 1f2565780e.

The 'hotplug-status' node should not be removed as long as the vif
device remains configured. Otherwise the xen-netback would wait for
re-running the network script even if it was already called (in case of
the frontent re-connecting). But also, it _should_ be removed when the
vif device is destroyed (for example when unbinding the driver) -
otherwise hotplug script would not configure the device whenever it
re-appear.

Moving removal of the 'hotplug-status' node was a workaround for nothing
calling network script after xen-netback module is reloaded. But when
vif interface is re-created (on xen-netback unbind/bind for example),
the script should be called, regardless of who does that - currently
this case is not handled by the toolstack, and requires manual
script call. Keeping hotplug-status=connected to skip the call is wrong
and leads to not configured interface.

More discussion at
https://lore.kernel.org/xen-devel/afedd7cb-a291-e773-8b0d-4db9b291fa98@ipxe.org/T/#u

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Link: https://lore.kernel.org/r/20220222001817.2264967-1-marmarek@invisiblethingslab.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-24 08:58:37 -08:00
Juergen Gross
be81992f90 xen/netback: don't queue unlimited number of packages
In case a guest isn't consuming incoming network traffic as fast as it
is coming in, xen-netback is buffering network packages in unlimited
numbers today. This can result in host OOM situations.

Commit f48da8b14d ("xen-netback: fix unlimited guest Rx internal
queue and carrier flapping") meant to introduce a mechanism to limit
the amount of buffered data by stopping the Tx queue when reaching the
data limit, but this doesn't work for cases like UDP.

When hitting the limit don't queue further SKBs, but drop them instead.
In order to be able to tell Rx packages have been dropped increment the
rx_dropped statistics counter in this case.

It should be noted that the old solution to continue queueing SKBs had
the additional problem of an overflow of the 32-bit rx_queue_len value
would result in intermittent Tx queue enabling.

This is part of XSA-392

Fixes: f48da8b14d ("xen-netback: fix unlimited guest Rx internal queue and carrier flapping")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2021-12-16 08:43:12 +01:00
Juergen Gross
6032046ec4 xen/netback: fix rx queue stall detection
Commit 1d5d485239 ("xen-netback: require fewer guest Rx slots when
not using GSO") introduced a security problem in netback, as an
interface would only be regarded to be stalled if no slot is available
in the rx queue ring page. In case the SKB at the head of the queued
requests will need more than one rx slot and only one slot is free the
stall detection logic will never trigger, as the test for that is only
looking for at least one slot to be free.

Fix that by testing for the needed number of slots instead of only one
slot being available.

In order to not have to take the rx queue lock that often, store the
number of needed slots in the queue data. As all SKB dequeue operations
happen in the rx queue kernel thread this is safe, as long as the
number of needed slots is accessed via READ/WRITE_ONCE() only and
updates are always done with the rx queue lock held.

Add a small helper for obtaining the number of free slots.

This is part of XSA-392

Fixes: 1d5d485239 ("xen-netback: require fewer guest Rx slots when not using GSO")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
2021-12-16 08:42:56 +01:00
Jakub Kicinski
9377211441 net: xen: use eth_hw_addr_set()
Commit 406f42fa0d ("net-next: When a bond have a massive amount
of VLANs...") introduced a rbtree for faster Ethernet address look
up. To maintain netdev->dev_addr in this tree we need to make all
the writes to it got through appropriate helpers.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-22 10:15:54 -07:00
Colin Ian King
bacc8daf97 xen-netback: Remove redundant initialization of variable err
The variable err is being initialized with a value that is never read, it
is being updated immediately afterwards. The assignment is redundant and
can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-15 11:02:36 +01:00
Jan Beulich
3ede7f84c7 xen-netback: correct success/error reporting for the SKB-with-fraglist case
When re-entering the main loop of xenvif_tx_check_gop() a 2nd time, the
special considerations for the head of the SKB no longer apply. Don't
mistakenly report ERROR to the frontend for the first entry in the list,
even if - from all I can tell - this shouldn't matter much as the overall
transmit will need to be considered failed anyway.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-19 12:10:26 +01:00
Roger Pau Monne
107866a8eb xen-netback: take a reference to the RX task thread
Do this in order to prevent the task from being freed if the thread
returns (which can be triggered by the frontend) before the call to
kthread_stop done as part of the backend tear down. Not taking the
reference will lead to a use-after-free in that scenario. Such
reference was taken before but dropped as part of the rework done in
2ac061ce97.

Reintroduce the reference taking and add a comment this time
explaining why it's needed.

This is XSA-374 / CVE-2021-28691.

Fixes: 2ac061ce97 ('xen/netback: cleanup init and deinit code')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
2021-06-07 15:13:15 +02:00
Michael Brown
2afeec08ab xen-netback: Check for hotplug-status existence before watching
The logic in connect() is currently written with the assumption that
xenbus_watch_pathfmt() will return an error for a node that does not
exist.  This assumption is incorrect: xenstore does allow a watch to
be registered for a nonexistent node (and will send notifications
should the node be subsequently created).

As of commit 1f2565780 ("xen-netback: remove 'hotplug-status' once it
has served its purpose"), this leads to a failure when a domU
transitions into XenbusStateConnected more than once.  On the first
domU transition into Connected state, the "hotplug-status" node will
be deleted by the hotplug_status_changed() callback in dom0.  On the
second or subsequent domU transition into Connected state, the
hotplug_status_changed() callback will therefore never be invoked, and
so the backend will remain stuck in InitWait.

This failure prevents scenarios such as reloading the xen-netfront
module within a domU, or booting a domU via iPXE.  There is
unfortunately no way for the domU to work around this dom0 bug.

Fix by explicitly checking for existence of the "hotplug-status" node,
thereby creating the behaviour that was previously assumed to exist.

Signed-off-by: Michael Brown <mbrown@fensystems.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-13 15:24:14 -07:00
Linus Torvalds
05a59d7979 Merge git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Fix transmissions in dynamic SMPS mode in ath9k, from Felix Fietkau.

 2) TX skb error handling fix in mt76 driver, also from Felix.

 3) Fix BPF_FETCH atomic in x86 JIT, from Brendan Jackman.

 4) Avoid double free of percpu pointers when freeing a cloned bpf prog.
    From Cong Wang.

 5) Use correct printf format for dma_addr_t in ath11k, from Geert
    Uytterhoeven.

 6) Fix resolve_btfids build with older toolchains, from Kun-Chuan
    Hsieh.

 7) Don't report truncated frames to mac80211 in mt76 driver, from
    Lorenzop Bianconi.

 8) Fix watcdog timeout on suspend/resume of stmmac, from Joakim Zhang.

 9) mscc ocelot needs NET_DEVLINK selct in Kconfig, from Arnd Bergmann.

10) Fix sign comparison bug in TCP_ZEROCOPY_RECEIVE getsockopt(), from
    Arjun Roy.

11) Ignore routes with deleted nexthop object in mlxsw, from Ido
    Schimmel.

12) Need to undo tcp early demux lookup sometimes in nf_nat, from
    Florian Westphal.

13) Fix gro aggregation for udp encaps with zero csum, from Daniel
    Borkmann.

14) Make sure to always use imp*_ndo_send when necessaey, from Jason A.
    Donenfeld.

15) Fix TRSCER masks in sh_eth driver from Sergey Shtylyov.

16) prevent overly huge skb allocationsd in qrtr, from Pavel Skripkin.

17) Prevent rx ring copnsumer index loss of sync in enetc, from Vladimir
    Oltean.

18) Make sure textsearch copntrol block is large enough, from Wilem de
    Bruijn.

19) Revert MAC changes to r8152 leading to instability, from Hates Wang.

20) Advance iov in 9p even for empty reads, from Jissheng Zhang.

21) Double hook unregister in nftables, from PabloNeira Ayuso.

22) Fix memleak in ixgbe, fropm Dinghao Liu.

23) Avoid dups in pkt scheduler class dumps, from Maximilian Heyne.

24) Various mptcp fixes from Florian Westphal, Paolo Abeni, and Geliang
    Tang.

25) Fix DOI refcount bugs in cipso, from Paul Moore.

26) One too many irqsave in ibmvnic, from Junlin Yang.

27) Fix infinite loop with MPLS gso segmenting via virtio_net, from
    Balazs Nemeth.

* git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net: (164 commits)
  s390/qeth: fix notification for pending buffers during teardown
  s390/qeth: schedule TX NAPI on QAOB completion
  s390/qeth: improve completion of pending TX buffers
  s390/qeth: fix memory leak after failed TX Buffer allocation
  net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0
  net: check if protocol extracted by virtio_net_hdr_set_proto is correct
  net: dsa: xrs700x: check if partner is same as port in hsr join
  net: lapbether: Remove netif_start_queue / netif_stop_queue
  atm: idt77252: fix null-ptr-dereference
  atm: uPD98402: fix incorrect allocation
  atm: fix a typo in the struct description
  net: qrtr: fix error return code of qrtr_sendmsg()
  mptcp: fix length of ADD_ADDR with port sub-option
  net: bonding: fix error return code of bond_neigh_init()
  net: enetc: allow hardware timestamping on TX queues with tc-etf enabled
  net: enetc: set MAC RX FIFO to recommended value
  net: davicom: Use platform_get_irq_optional()
  net: davicom: Fix regulator not turned off on driver removal
  net: davicom: Fix regulator not turned off on failed probe
  net: dsa: fix switchdev objects on bridge master mistakenly being applied on ports
  ...
2021-03-09 17:15:56 -08:00
Jan Beulich
2991397d23 xen-netback: respect gnttab_map_refs()'s return value
Commit 3194a1746e ("xen-netback: don't "handle" error by BUG()")
dropped respective a BUG_ON() without noticing that with this the
variable's value wouldn't be consumed anymore. With gnttab_set_map_op()
setting all status fields to a non-zero value, in case of an error no
slot should have a status of GNTST_okay (zero).

This is part of XSA-367.

Cc: <stable@vger.kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/d933f495-619a-0086-5fb4-1ec3cf81a8fc@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2021-03-03 08:32:11 +01:00
Jan Beulich
826d82170b xen-netback: use local var in xenvif_tx_check_gop() instead of re-calculating
shinfo already holds the result of skb_shinfo(skb) at this point - no
need to re-invoke the construct even twice.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-01 13:05:08 -08:00
Linus Torvalds
4a037ad5d1 xen: branch for v5.12-rc1
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Merge tag 'for-linus-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:
 "A series of Xen related security fixes, all related to limited error
  handling in Xen backend drivers"

* tag 'for-linus-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen-blkback: fix error handling in xen_blkbk_map()
  xen-scsiback: don't "handle" error by BUG()
  xen-netback: don't "handle" error by BUG()
  xen-blkback: don't "handle" error by BUG()
  xen/arm: don't ignore return errors from set_phys_to_machine
  Xen/gntdev: correct error checking in gntdev_map_grant_pages()
  Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages()
  Xen/x86: also check kernel mapping in set_foreign_p2m_mapping()
  Xen/x86: don't bail early from clear_foreign_p2m_mapping()
2021-02-21 13:06:08 -08:00
Jan Beulich
3194a1746e xen-netback: don't "handle" error by BUG()
In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.

This is part of XSA-362.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
2021-02-15 08:55:31 +01:00
Juergen Gross
f2fa0e5e9f xen/events: link interdomain events to associated xenbus device
In order to support the possibility of per-device event channel
settings (e.g. lateeoi spurious event thresholds) add a xenbus device
pointer to struct irq_info() and modify the related event channel
binding interfaces to take the pointer to the xenbus device as a
parameter instead of the domain id of the other side.

While at it remove the stale prototype of bind_evtchn_to_irq_lateeoi().

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-11 14:47:00 -08:00
Juergen Gross
a3daf3d391 xen/netback: fix spurious event detection for common event case
In case of a common event for rx and tx queue the event should be
regarded to be spurious if no rx and no tx requests are pending.

Unfortunately the condition for testing that is wrong causing to
decide a event being spurious if no rx OR no tx requests are
pending.

Fix that plus using local variables for rx/tx pending indicators in
order to split function calls and if condition.

Fixes: 23025393db ("xen/netback: use lateeoi irq binding")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Wei Liu <wl@xen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-11 14:47:00 -08:00
David S. Miller
dc9d87581d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-02-10 13:30:12 -08:00
Juergen Gross
ec7d8e7dd3 xen/netback: avoid race in xenvif_rx_ring_slots_available()
Since commit 23025393db ("xen/netback: use lateeoi irq binding")
xenvif_rx_ring_slots_available() is no longer called only from the rx
queue kernel thread, so it needs to access the rx queue with the
associated queue held.

Reported-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Fixes: 23025393db ("xen/netback: use lateeoi irq binding")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Link: https://lore.kernel.org/r/20210202070938.7863-1-jgross@suse.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-04 10:54:37 -08:00
Lee Jones
090c7ae8e0 net: xen-netback: xenbus: Demote nonconformant kernel-doc headers
Fixes the following W=1 kernel build warning(s):

 drivers/net/xen-netback/xenbus.c:419: warning: Function parameter or member 'dev' not described in 'frontend_changed'
 drivers/net/xen-netback/xenbus.c:419: warning: Function parameter or member 'frontend_state' not described in 'frontend_changed'
 drivers/net/xen-netback/xenbus.c:1001: warning: Function parameter or member 'dev' not described in 'netback_probe'
 drivers/net/xen-netback/xenbus.c:1001: warning: Function parameter or member 'id' not described in 'netback_probe'

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-16 18:13:04 -08:00
Jonathan Lemon
06b4feb37e net: group skb_shinfo zerocopy related bits together.
In preparation for expanded zerocopy (TX and RX), move
the zerocopy related bits out of tx_flags into their own
flag word.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-07 16:08:37 -08:00
Jonathan Lemon
36177832f4 skbuff: Add skb parameter to the ubuf zerocopy callback
Add an optional skb parameter to the zerocopy callback parameter,
which is passed down from skb_zcopy_clear().  This gives access
to the original skb, which is needed for upcoming RX zero-copy
error handling.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-07 16:06:37 -08:00
SeongJae Park
2e85d32b1c xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()
Some code does not directly make 'xenbus_watch' object and call
'register_xenbus_watch()' but use 'xenbus_watch_path()' instead.  This
commit adds support of 'will_handle' callback in the
'xenbus_watch_path()' and it's wrapper, 'xenbus_watch_pathfmt()'.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reported-by: Michael Kurth <mku@amazon.de>
Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
2020-12-14 10:04:18 +01:00
SeongJae Park
fed1755b11 xen/xenbus: Allow watches discard events before queueing
If handling logics of watch events are slower than the events enqueue
logic and the events can be created from the guests, the guests could
trigger memory pressure by intensively inducing the events, because it
will create a huge number of pending events that exhausting the memory.

Fortunately, some watch events could be ignored, depending on its
handler callback.  For example, if the callback has interest in only one
single path, the watch wouldn't want multiple pending events.  Or, some
watches could ignore events to same path.

To let such watches to volutarily help avoiding the memory pressure
situation, this commit introduces new watch callback, 'will_handle'.  If
it is not NULL, it will be called for each new event just before
enqueuing it.  Then, if the callback returns false, the event will be
discarded.  No watch is using the callback for now, though.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reported-by: Michael Kurth <mku@amazon.de>
Reported-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
2020-12-14 10:02:45 +01:00
Juergen Gross
23025393db xen/netback: use lateeoi irq binding
In order to reduce the chance for the system becoming unresponsive due
to event storms triggered by a misbehaving netfront use the lateeoi
irq binding for netback and unmask the event channel only just before
going to sleep waiting for new events.

Make sure not to issue an EOI when none is pending by introducing an
eoi_pending element to struct xenvif_queue.

When no request has been consumed set the spurious flag when sending
the EOI for an interrupt.

This is part of XSA-332.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wl@xen.org>
2020-10-20 10:22:03 +02:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Denis Kirjanov
1c9535c701 xen networking: add XDP offset adjustment to xen-netback
the patch basically adds the offset adjustment and netfront
state reading to make XDP work on netfront side.

Reviewed-by: Paul Durrant <paul@xen.org>
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-01 15:25:14 -07:00
Madhuparna Bhowmik
f3265971de net: xen-netback: hash.c: Use built-in RCU list checking
list_for_each_entry_rcu has built-in RCU and lock checking.
Pass cond argument to list_for_each_entry_rcu.

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik04@gmail.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-17 10:57:22 +01:00
Paul Durrant
9476654bd5 xen-netback: support dynamic unbind/bind
By re-attaching RX, TX, and CTL rings during connect() rather than
assuming they are freshly allocated (i.e. assuming the counters are zero),
and avoiding forcing state to Closed in netback_remove() it is possible
for vif instances to be unbound and re-bound from and to (respectively) a
running guest.

Dynamic unbind/bind is a highly useful feature for a backend module as it
allows it to be unloaded and re-loaded (i.e. updated) without requiring
domUs to be halted.

This has been tested by running iperf as a server in the test VM and
then running a client against it in a continuous loop, whilst also
running:

while true;
  do echo vif-$DOMID-$VIF >unbind;
  echo down;
  rmmod xen-netback;
  echo unloaded;
  modprobe xen-netback;
  cd $(pwd);
  brctl addif xenbr0 vif$DOMID.$VIF;
  ip link set vif$DOMID.$VIF up;
  echo up;
  sleep 5;
  done

in dom0 from /sys/bus/xen-backend/drivers/vif to continuously unbind,
unload, re-load, re-bind and re-plumb the backend.

Clearly a performance drop was seen but no TCP connection resets were
observed during this test and moreover a parallel SSH connection into the
guest remained perfectly usable throughout.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-26 15:16:26 -08:00
David S. Miller
ac80010fc9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Mere overlapping changes in the conflicts here.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-22 15:15:05 -08:00
Paul Durrant
1f2565780e xen-netback: remove 'hotplug-status' once it has served its purpose
Removing the 'hotplug-status' node in netback_remove() is wrong; the script
may not have completed. Only remove the node once the watch has fired and
has been unregistered.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17 23:03:33 -08:00
Paul Durrant
f55c3188df xen-netback: switch state to InitWait at the end of netback_probe()...
...as the comment above the function states.

The switch to Initialising at the start of the function is somewhat bogus
as the toolstack will have set that initial state anyway. To behave
correctly, a backend should switch to InitWait once it has set up all
xenstore values that may be required by a initialising frontend. This
patch calls backend_switch_state() to make the transition at the
appropriate point.

NOTE: backend_switch_state() ignores errors from xenbus_switch_state()
      and so this patch removes an error path from netback_probe(). This
      means a failure to change state at this stage (in the absence of
      other failures) will leave the device instantiated. This is highly
      unlikley to happen as a failure to change state would indicate a
      failure to write to xenstore, and that will trigger other error
      paths. Also, a 'stuck' device can still be cleaned up using 'unbind'
      in any case.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17 23:03:33 -08:00
Paul Durrant
92fbeb43b6 xen-netback: move netback_probe() and netback_remove() to the end...
...of xenbus.c

This is a cosmetic function re-ordering to reduce churn in a subsequent
patch. Some style fix-up was done to make checkpatch.pl happier.

No functional change.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17 23:03:33 -08:00
Paul Durrant
fd42bfd1bb xen-netback: avoid race that can lead to NULL pointer dereference
In function xenvif_disconnect_queue(), the value of queue->rx_irq is
zeroed *before* queue->task is stopped. Unfortunately that task may call
notify_remote_via_irq(queue->rx_irq) and calling that function with a
zero value results in a NULL pointer dereference in evtchn_from_irq().

This patch simply re-orders things, stopping all tasks before zero-ing the
irq values, thereby avoiding the possibility of the race.

Fixes: 2ac061ce97 ("xen/netback: cleanup init and deinit code")
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-12-15 11:40:15 -08:00
Juergen Gross
2ac061ce97 xen/netback: cleanup init and deinit code
Do some cleanup of the netback init and deinit code:

- add an omnipotent queue deinit function usable from
  xenvif_disconnect_data() and the error path of xenvif_connect_data()
- only install the irq handlers after initializing all relevant items
  (especially the kthreads related to the queue)
- there is no need to use get_task_struct() after creating a kthread
  and using put_task_struct() again after having stopped it.
- use kthread_run() instead of kthread_create() to spare the call of
  wake_up_process().

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <pdurrant@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-22 09:52:04 -07:00
Juergen Gross
3d5c1a037d xen/netback: fix error path of xenvif_connect_data()
xenvif_connect_data() calls module_put() in case of error. This is
wrong as there is no related module_get().

Remove the superfluous module_put().

Fixes: 279f438e36 ("xen-netback: Don't destroy the netdev until the vif is shut down")
Cc: <stable@vger.kernel.org> # 3.12
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-19 11:43:29 -07:00
David S. Miller
446bf64b61 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge conflict of mlx5 resolved using instructions in merge
commit 9566e650bf.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-19 11:54:03 -07:00
Greg Kroah-Hartman
6f20a697e4 xen-netback: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Wei Liu <wei.liu@kernel.org>
Cc: Paul Durrant <paul.durrant@citrix.com>
Cc: xen-devel@lists.xenproject.org
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-11 21:30:06 -07:00
Ross Lagerwall
3a0233ddec xen/netback: Reset nr_frags before freeing skb
At this point nr_frags has been incremented but the frag does not yet
have a page assigned so freeing the skb results in a crash. Reset
nr_frags before freeing the skb to prevent this.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-08 18:01:24 -07:00
Jonathan Lemon
b54c9d5bd6 net: Use skb_frag_off accessors
Use accessor functions for skb fragment's page_offset instead
of direct references, in preparation for bvec conversion.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-30 14:21:32 -07:00
Matthew Wilcox (Oracle)
d7840976e3 net: Use skb accessors in network drivers
In preparation for unifying the skb_frag and bio_vec, use the fine
accessors which already exist and use skb_frag_t instead of
struct skb_frag_struct.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-22 20:47:56 -07:00
Colin Ian King
587a712677 xen-netback: remove redundant assignment to err
The variable err is assigned with the value -ENOMEM that is never
read and it is re-assigned a new value later on.  The assignment is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-31 14:36:48 -07:00
Thomas Gleixner
1ccea77e2a treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that 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

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that 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 [based]
  [from] [clk] [highbank] [c] 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-or-later

has been chosen to replace the boilerplate/reference in 355 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190519154041.837383322@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 11:28:45 +02:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Dongli Zhang
6dc400af21 xen-netback: add reference from xenvif to backend_info to facilitate coredump analysis
During coredump analysis, it is not easy to obtain the address of
backend_info in xen-netback.

So far there are two ways to obtain backend_info:

1. Do what xenbus_device_find() does for vmcore to find the xenbus_device
and then derive it from dev_get_drvdata().

2. Extract backend_info from callstack of xenwatch (e.g., netback_remove()
or frontend_changed()).

This patch adds a reference from xenvif to backend_info so that it would be
much more easier to obtain backend_info during coredump analysis.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-12 10:10:28 -07:00
Paolo Abeni
a350eccee5 net: remove 'fallback' argument from dev->ndo_select_queue()
After the previous patch, all the callers of ndo_select_queue()
provide as a 'fallback' argument netdev_pick_tx.
The only exceptions are nested calls to ndo_select_queue(),
which pass down the 'fallback' available in the current scope
- still netdev_pick_tx.

We can drop such argument and replace fallback() invocation with
netdev_pick_tx(). This avoids an indirect call per xmit packet
in some scenarios (TCP syn, UDP unconnected, XDP generic, pktgen)
with device drivers implementing such ndo. It also clean the code
a bit.

Tested with ixgbe and CONFIG_FCOE=m

With pktgen using queue xmit:
threads		vanilla 	patched
		(kpps)		(kpps)
1		2334		2428
2		4166		4278
4		7895		8100

 v1 -> v2:
 - rebased after helper's name change

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-20 11:18:55 -07:00
David S. Miller
9eb359140c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-03-02 12:54:35 -08:00
Igor Druzhinin
a2288d4e35 xen-netback: don't populate the hash cache on XenBus disconnect
Occasionally, during the disconnection procedure on XenBus which
includes hash cache deinitialization there might be some packets
still in-flight on other processors. Handling of these packets includes
hashing and hash cache population that finally results in hash cache
data structure corruption.

In order to avoid this we prevent hashing of those packets if there
are no queues initialized. In that case RCU protection of queues guards
the hash cache as well.

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28 12:50:37 -08:00
Igor Druzhinin
99e87f56b4 xen-netback: fix occasional leak of grant ref mappings under memory pressure
Zero-copy callback flag is not yet set on frag list skb at the moment
xenvif_handle_frag_list() returns -ENOMEM. This eventually results in
leaking grant ref mappings since xenvif_zerocopy_callback() is never
called for these fragments. Those eventually build up and cause Xen
to kill Dom0 as the slots get reused for new mappings:

"d0v0 Attempt to implicitly unmap a granted PTE c010000329fce005"

That behavior is observed under certain workloads where sudden spikes
of page cache writes coexist with active atomic skb allocations from
network traffic. Additionally, rework the logic to deal with frag_list
deallocation in a single place.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28 10:36:38 -08:00
Maxim Mikityanskiy
d2aa125d62 net: Don't set transport offset to invalid value
If the socket was created with socket(AF_PACKET, SOCK_RAW, 0),
skb->protocol will be unset, __skb_flow_dissect() will fail, and
skb_probe_transport_header() will fall back to the offset_hint, making
the resulting skb_transport_offset incorrect.

If, however, there is no transport header in the packet,
transport_header shouldn't be set to an arbitrary value.

Fix it by leaving the transport offset unset if it couldn't be found, to
be explicit rather than to fill it with some wrong value. It changes the
behavior, but if some code relied on the old behavior, it would be
broken anyway, as the old one is incorrect.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-22 12:55:31 -08:00
Gustavo A. R. Silva
7499a288bf xen-netback: mark expected switch fall-through
In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enabling
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-08 12:21:21 -08:00