linux-toradex.git/drivers/net/xen-netfront.c, branch v4.4.129

xen-netfront: Fix hang on device removal

2018-04-24T07:32:06+00:00

commit c2d2e6738a209f0f9dffa2dc8e7292fc45360d61 upstream.

A toolstack may delete the vif frontend and backend xenstore entries
while xen-netfront is in the removal code path.  In that case, the
checks for xenbus_read_driver_state would return XenbusStateUnknown, and
xennet_remove would hang indefinitely.  This hang prevents system
shutdown.

xennet_remove must be able to handle XenbusStateUnknown, and
netback_changed must also wake up the wake_queue for that state as well.

Fixes: 5b5971df3bc2 ("xen-netfront: remove warning when unloading module")

Signed-off-by: Jason Andryuk 
Cc: Eduardo Otubo 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen-netfront: enable device after manual module load

2018-03-03T09:19:45+00:00

[ Upstream commit b707fda2df4070785d0fa8a278aa13944c5f51f8 ]

When loading the module after unloading it, the network interface would
not be enabled and thus wouldn't have a backend counterpart and unable
to be used by the guest.

The guest would face errors like:

  [root@guest ~]# ethtool -i eth0
  Cannot get driver information: No such device

  [root@guest ~]# ifconfig eth0
  eth0: error fetching interface information: Device not found

This patch initializes the state of the netfront device whenever it is
loaded manually, this state would communicate the netback to create its
device and establish the connection between them.

Signed-off-by: Eduardo Otubo 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

xen-netfront: remove warning when unloading module

2018-02-03T16:04:28+00:00

[ Upstream commit 5b5971df3bc2775107ddad164018a8a8db633b81 ]

v2:
 * Replace busy wait with wait_event()/wake_up_all()
 * Cannot garantee that at the time xennet_remove is called, the
   xen_netback state will not be XenbusStateClosed, so added a
   condition for that
 * There's a small chance for the xen_netback state is
   XenbusStateUnknown by the time the xen_netfront switches to Closed,
   so added a condition for that.

When unloading module xen_netfront from guest, dmesg would output
warning messages like below:

  [  105.236836] xen:grant_table: WARNING: g.e. 0x903 still in use!
  [  105.236839] deferring g.e. 0x903 (pfn 0x35805)

This problem relies on netfront and netback being out of sync. By the time
netfront revokes the g.e.'s netback didn't have enough time to free all of
them, hence displaying the warnings on dmesg.

The trick here is to make netfront to wait until netback frees all the g.e.'s
and only then continue to cleanup for the module removal, and this is done by
manipulating both device states.

Signed-off-by: Eduardo Otubo 
Acked-by: Juergen Gross 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

xen-netfront: avoid crashing on resume after a failure in talk_to_netback()

2017-12-09T17:42:44+00:00

commit d86b5672b1adb98b4cdd6fbf0224bbfb03db6e2e upstream.

Unavoidable crashes in netfront_resume() and netback_changed() after a
previous fail in talk_to_netback() (e.g. when we fail to read MAC from
xenstore) were discovered. The failure path in talk_to_netback() does
unregister/free for netdev but we don't reset drvdata and we try accessing
it after resume.

Fix the bug by removing the whole xen device completely with
device_unregister(), this guarantees we won't have any calls into netfront
after a failure.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: David S. Miller 
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

xen-netfront: Improve error handling during initialization

2017-12-09T17:42:43+00:00

[ Upstream commit e2e004acc7cbe3c531e752a270a74e95cde3ea48 ]

This fixes a crash when running out of grant refs when creating many
queues across many netdevs.

* If creating queues fails (i.e. there are no grant refs available),
call xenbus_dev_fatal() to ensure that the xenbus device is set to the
closed state.
* If no queues are created, don't call xennet_disconnect_backend as
netdev->real_num_tx_queues will not have been set correctly.
* If setup_netfront() fails, ensure that all the queues created are
cleaned up, not just those that have been set up.
* If any queues were set up and an error occurs, call
xennet_destroy_queues() to clean up the napi context.
* If any fatal error occurs, unregister and destroy the netdev to avoid
leaving around a half setup network device.

Signed-off-by: Ross Lagerwall 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

xen-netfront: Fix Rx stall during network stress and OOM

2017-07-05T12:37:18+00:00

[ Upstream commit 90c311b0eeead647b708a723dbdde1eda3dcad05 ]

During an OOM scenario, request slots could not be created as skb
allocation fails. So the netback cannot pass in packets and netfront
wrongly assumes that there is no more work to be done and it disables
polling. This causes Rx to stall.

The issue is with the retry logic which schedules the timer if the
created slots are less than NET_RX_SLOTS_MIN. The count of new request
slots to be pushed are calculated as a difference between new req_prod
and rsp_cons which could be more than the actual slots, if there are
unconsumed responses.

The fix is to calculate the count of newly created slots as the
difference between new req_prod and old req_prod.

Signed-off-by: Vineeth Remanan Pillai 
Reviewed-by: Juergen Gross 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

xen-netfront: cast grant table reference first to type int

2017-06-14T11:16:22+00:00

commit 269ebce4531b8edc4224259a02143181a1c1d77c upstream.

IS_ERR_VALUE() in commit 87557efc27f6a50140fb20df06a917f368ce3c66
("xen-netfront: do not cast grant table reference to signed short") would
not return true for error code unless we cast ref first to type int.

Signed-off-by: Dongli Zhang 
Signed-off-by: David S. Miller 
Cc: Blake Cooper 
Signed-off-by: Greg Kroah-Hartman

xen-netfront: do not cast grant table reference to signed short

2017-06-14T11:16:22+00:00

commit 87557efc27f6a50140fb20df06a917f368ce3c66 upstream.

While grant reference is of type uint32_t, xen-netfront erroneously casts
it to signed short in BUG_ON().

This would lead to the xen domU panic during boot-up or migration when it
is attached with lots of paravirtual devices.

Signed-off-by: Dongli Zhang 
Signed-off-by: David S. Miller 
Cc: Blake Cooper 
Signed-off-by: Greg Kroah-Hartman

xen-netfront: Delete rx_refill_timer in xennet_disconnect_backend()

2017-02-14T23:22:52+00:00

commit 74470954857c264168d2b5a113904cf0cfd27d18 upstream.

rx_refill_timer should be deleted as soon as we disconnect from the
backend since otherwise it is possible for the timer to go off before
we get to xennet_destroy_queues(). If this happens we may dereference
queue->rx.sring which is set to NULL in xennet_disconnect_backend().

Signed-off-by: Boris Ostrovsky 
Reviewed-by: Juergen Gross 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-linus-4.4-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2015-11-05T01:32:42+00:00

Pull xen updates from David Vrabel:

 - Improve balloon driver memory hotplug placement.

 - Use unpopulated hotplugged memory for foreign pages (if
   supported/enabled).

 - Support 64 KiB guest pages on arm64.

 - CPU hotplug support on arm/arm64.

* tag 'for-linus-4.4-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (44 commits)
  xen: fix the check of e_pfn in xen_find_pfn_range
  x86/xen: add reschedule point when mapping foreign GFNs
  xen/arm: don't try to re-register vcpu_info on cpu_hotplug.
  xen, cpu_hotplug: call device_offline instead of cpu_down
  xen/arm: Enable cpu_hotplug.c
  xenbus: Support multiple grants ring with 64KB
  xen/grant-table: Add an helper to iterate over a specific number of grants
  xen/xenbus: Rename *RING_PAGE* to *RING_GRANT*
  xen/arm: correct comment in enlighten.c
  xen/gntdev: use types from linux/types.h in userspace headers
  xen/gntalloc: use types from linux/types.h in userspace headers
  xen/balloon: Use the correct sizeof when declaring frame_list
  xen/swiotlb: Add support for 64KB page granularity
  xen/swiotlb: Pass addresses rather than frame numbers to xen_arch_need_swiotlb
  arm/xen: Add support for 64KB page granularity
  xen/privcmd: Add support for Linux 64KB page granularity
  net/xen-netback: Make it running on 64KB page granularity
  net/xen-netfront: Make it running on 64KB page granularity
  block/xen-blkback: Make it running on 64KB page granularity
  block/xen-blkfront: Make it running on 64KB page granularity
  ...