Netback and netfront only use one event channel to do TX / RX notification,
which may cause unnecessary wake-up of processing routines. This patch adds a
new feature called feature-split-event-channels to netback, enabling it to
handle TX and RX events separately.
Netback will use tx_irq to notify guest for TX completion, rx_irq for RX
notification.
If frontend doesn't support this feature, tx_irq equals to rx_irq.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch enables user to unload netback module, which is useful when user
wants to upgrade to a newer netback module without rebooting the host.
Netfront cannot handle netback removal event. As we cannot fix all possible
frontends we add module get / put along with vif get / put to avoid
mis-unloading of netback. To unload netback module, user needs to shutdown all
VMs or migrate them to another host or unplug all vifs before hand.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>¬
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull in 'net' to take in the bug fixes that didn't make it into
3.8-final.
Also, deal with the semantic conflict of the change made to
net/ipv6/xfrm6_policy.c A missing rt6->n neighbour release
was added to 'net', but in 'net-next' we no longer cache the
neighbour entries in the ipv6 routes so that change is not
appropriate there.
Signed-off-by: David S. Miller <davem@davemloft.net>
If the credit timer is left armed after calling
xen_netbk_remove_xenvif(), then it may fire and attempt to schedule
the vif which will then oops as vif->netbk == NULL.
This may happen both in the fatal error path and during normal
disconnection from the front end.
The sequencing during shutdown is critical to ensure that: a)
vif->netbk doesn't become unexpectedly NULL; and b) the net device/vif
is not freed.
1. Mark as unschedulable (netif_carrier_off()).
2. Synchronously cancel the timer.
3. Remove the vif from the schedule list.
4. Remove it from it netback thread group.
5. Wait for vif->refcnt to become 0.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reported-by: Christopher S. Aker <caker@theshore.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Synchronize with 'net' in order to sort out some l2tp, wireless, and
ipv6 GRE fixes that will be built on top of in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
A buggy or malicious frontend should not be able to confuse netback.
If we spot anything which is not as it should be then shutdown the
device and don't try to continue with the ring in a potentially
hostile state. Well behaved and non-hostile frontends will not be
penalised.
As well as making the existing checks for such errors fatal also add a
new check that ensures that there isn't an insane number of requests
on the ring (i.e. more than would fit in the ring). If the ring
contains garbage then previously is was possible to loop over this
insane number, getting an error each time and therefore not generating
any more pending requests and therefore not exiting the loop in
xen_netbk_tx_build_gops for an externded period.
Also turn various netdev_dbg calls which no precipitate a fatal error
into netdev_err, they are rate limited because the device is shutdown
afterwards.
This fixes at least one known DoS/softlockup of the backend domain.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sometimes it is useful to be able to change the MAC address of the
interface for netback devices. For example, when using ebtables it may
be useful to be able to distinguish traffic from different interfaces
without depending on the interface name.
Reported-by: Nikita Borzykh <sample.n@gmail.com>
Reported-by: Paul Harvey <stockingpaul@hotmail.com>
Cc: netdev@vger.kernel.org
Cc: xen-devel@lists.xen.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Matt Wilson <msw@amazon.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All tables of function pointers should be const to make hacks
more difficult. Compile tested only.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
v2: add couple missing conversions in drivers
split unexporting netdev_fix_features()
implemented %pNF
convert sock::sk_route_(no?)caps
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a VM is saved and restored (or migrated) the netback driver will no
longer process any Tx packets from the frontend. xenvif_up() does not
schedule the processing of any pending Tx requests from the front end
because the carrier is off. Without this initial kick the frontend
just adds Tx requests to the ring without raising an event (until the
ring is full).
This was caused by 47103041e9 (net:
xen-netback: convert to hw_features) which reordered the calls to
xenvif_up() and netif_carrier_on() in xenvif_connect().
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netback is the host side counterpart to the frontend driver in
drivers/net/xen-netfront.c. The PV protocol is also implemented by
frontend drivers in other OSes too, such as the BSDs and even Windows.
The patch is based on the driver from the xen.git pvops kernel tree but
has been put through the checkpatch.pl wringer plus several manual
cleanup passes and review iterations. The driver has been moved from
drivers/xen/netback to drivers/net/xen-netback.
One major change from xen.git is that the guest transmit path (i.e. what
looks like receive to netback) has been significantly reworked to remove
the dependency on the out of tree PageForeign page flag (a core kernel
patch which enables a per page destructor callback on the final
put_page). This page flag was used in order to implement a grant map
based transmit path (where guest pages are mapped directly into SKB
frags). Instead this version of netback uses grant copy operations into
regular memory belonging to the backend domain. Reinstating the grant
map functionality is something which I would like to revisit in the
future.
Note that this driver depends on 2e820f58f7 "xen/irq: implement
bind_interdomain_evtchn_to_irqhandler for backend drivers" which is in
linux next via the "xen-two" tree and is intended for the 2.6.39 merge
window:
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/backends
this branch has only that single commit since 2.6.38-rc2 and is safe for
cross merging into the net branch.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
