linux-toradex.git/drivers/net/xen-netfront.c, branch v4.9.34

xen-netfront: Delete rx_refill_timer in xennet_disconnect_backend()

2017-02-14T23:25:40+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

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

2016-11-02T19:33:36+00:00

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

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

2016-10-31T20:05:32+00:00

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

xen-netfront: avoid packet loss when ethernet header crosses page boundary

2016-09-20T08:40:41+00:00

Small packet loss is reported on complex multi host network configurations
including tunnels, NAT, ... My investigation led me to the following check
in netback which drops packets:

        if (unlikely(txreq.size < ETH_HLEN)) {
                netdev_err(queue->vif->dev,
                           "Bad packet size: %d\n", txreq.size);
                xenvif_tx_err(queue, &txreq, extra_count, idx);
                break;
        }

But this check itself is legitimate. SKBs consist of a linear part (which
has to have the ethernet header) and (optionally) a number of frags.
Netfront transmits the head of the linear part up to the page boundary
as the first request and all the rest becomes frags so when we're
reconstructing the SKB in netback we can't distinguish between original
frags and the 'tail' of the linear part. The first SKB needs to be at
least ETH_HLEN size. So in case we have an SKB with its linear part
starting too close to the page boundary the packet is lost.

I see two ways to fix the issue:
- Change the 'wire' protocol between netfront and netback to start keeping
  the original SKB structure. We'll have to add a flag indicating the fact
  that the particular request is a part of the original linear part and not
  a frag. We'll need to know the length of the linear part to pre-allocate
  memory.
- Avoid transmitting SKBs with linear parts starting too close to the page
  boundary. That seems preferable short-term and shouldn't bring
  significant performance degradation as such packets are rare. That's what
  this patch is trying to achieve with skb_copy().

Signed-off-by: Vitaly Kuznetsov 
Acked-by: David Vrabel 
Signed-off-by: David S. Miller

xen-netfront: request Tx response events more often

2016-01-29T00:08:55+00:00

Trying to batch Tx response events results in poor performance because
this delays freeing the transmitted skbs.

Instead use the standard RING_FINAL_CHECK_FOR_RESPONSES() macro to be
notified once the next Tx response is placed on the ring.

Signed-off-by: Malcolm Crossley 
Signed-off-by: David Vrabel 
Signed-off-by: David S. Miller

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
  ...

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-10-24T13:54:12+00:00

Conflicts:
	net/ipv6/xfrm6_output.c
	net/openvswitch/flow_netlink.c
	net/openvswitch/vport-gre.c
	net/openvswitch/vport-vxlan.c
	net/openvswitch/vport.c
	net/openvswitch/vport.h

The openvswitch conflicts were overlapping changes.  One was
the egress tunnel info fix in 'net' and the other was the
vport ->send() op simplification in 'net-next'.

The xfrm6_output.c conflicts was also a simplification
overlapping a bug fix.

Signed-off-by: David S. Miller

net/xen-netfront: Make it running on 64KB page granularity

2015-10-23T13:20:40+00:00

The PV network protocol is using 4KB page granularity. The goal of this
patch is to allow a Linux using 64KB page granularity using network
device on a non-modified Xen.

It's only necessary to adapt the ring size and break skb data in small
chunk of 4KB. The rest of the code is relying on the grant table code.

Note that we allocate a Linux page for each rx skb but only the first
4KB is used. We may improve the memory usage by extending the size of
the rx skb.

Signed-off-by: Julien Grall 
Reviewed-by: David Vrabel 
Signed-off-by: David Vrabel

xen-netfront: update num_queues to real created

2015-10-21T14:45:39+00:00

Sometimes xennet_create_queues() may failed to created all requested
queues, we need to update num_queues to real created to avoid NULL
pointer dereference.

Signed-off-by: Joe Jin 
Cc: Boris Ostrovsky 
Cc: Konrad Rzeszutek Wilk 
Cc: Wei Liu 
Cc: Ian Campbell 
Cc: David S. Miller 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: David S. Miller

xen-netfront: always set num queues if possible

2015-09-21T04:39:21+00:00

If netfront connects with two (or more) queues and then reconnects with
only one queue it fails to delete or rewrite the multi-queue-num-queues
key and netback will try to use the wrong number of queues.

Always write the num-queues field if the backend has multi-queue support.

Signed-off-by: Chas Williams <3chas3@gmail.com>
Signed-off-by: David S. Miller