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path: root/drivers/net/xen-netback/xenbus.c
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* xen-netback: fix error handling on netback_probe()Filipe Manco2016-09-171-16/+30
| | | | | | | | | | | | | | | | | | In case of error during netback_probe() (e.g. an entry missing on the xenstore) netback_remove() is called on the new device, which will set the device backend state to XenbusStateClosed by calling set_backend_state(). However, the backend state wasn't initialized by netback_probe() at this point, which will cause and invalid transaction and set_backend_state() to BUG(). Initialize the backend state at the beginning of netback_probe() to XenbusStateInitialising, and create two new valid state transitions on set_backend_state(), from XenbusStateInitialising to XenbusStateClosed, and from XenbusStateInitialising to XenbusStateInitWait. Signed-off-by: Filipe Manco <filipe.manco@neclab.eu> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: add control ring boilerplatePaul Durrant2016-05-161-10/+69
| | | | | | | | | | | | | | | My recent patch to include/xen/interface/io/netif.h defines a new shared ring (in addition to the rx and tx rings) for passing control messages from a VM frontend driver to a backend driver. This patch adds the necessary code to xen-netback to map this new shared ring, should it be created by a frontend, but does not add implementations for any of the defined protocol messages. These are added in a subsequent patch for clarity. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: reduce log spamPaul Durrant2016-03-131-2/+0
| | | | | | | | | | | Remove the "prepare for reconnect" pr_info in xenbus.c. It's largely uninteresting and the states of the frontend and backend can easily be observed by watching the (o)xenstored log. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: implement dynamic multicast controlPaul Durrant2016-02-071-8/+81
| | | | | | | | | | | | | | | | My recent patch to the Xen Project documents a protocol for 'dynamic multicast control' in netif.h. This extends the previous multicast control protocol to not require a shared ring reconnection to turn the feature off. Instead the backend watches the "request-multicast-control" key in xenstore and turns the feature off if the key value is written to zero. This patch adds support for dynamic multicast control in xen-netback. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: correctly check failed allocationInsu Yun2015-10-181-0/+6
| | | | | | | | | Since vzalloc can be failed in memory pressure, writes -ENOMEM to xenstore to indicate error. Signed-off-by: Insu Yun <wuninsu@gmail.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: add support for multicast controlPaul Durrant2015-09-021-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | Xen's PV network protocol includes messages to add/remove ethernet multicast addresses to/from a filter list in the backend. This allows the frontend to request the backend only forward multicast packets which are of interest thus preventing unnecessary noise on the shared ring. The canonical netif header in git://xenbits.xen.org/xen.git specifies the message format (two more XEN_NETIF_EXTRA_TYPEs) so the minimal necessary changes have been pulled into include/xen/interface/io/netif.h. To prevent the frontend from extending the multicast filter list arbitrarily a limit (XEN_NETBK_MCAST_MAX) has been set to 64 entries. This limit is not specified by the protocol and so may change in future. If the limit is reached then the next XEN_NETIF_EXTRA_TYPE_MCAST_ADD sent by the frontend will be failed with NETIF_RSP_ERROR. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: fix a BUG() during initializationPalik, Imre2015-06-231-0/+4
| | | | | | | | | | | | | | | | | | | | Commit edafc132baac ("xen-netback: making the bandwidth limiter runtime settable") introduced the capability to change the bandwidth rate limit at runtime. But it also introduced a possible crashing bug. If netback receives two XenbusStateConnected without getting the hotplug-status watch firing in between, then it will try to register the watches for the rate limiter again. But this triggers a BUG() in the watch registration code. The fix modifies connect() to remove the possibly existing packet-rate watches before trying to install those watches. This behaviour is in line with how connect() deals with the hotplug-status watch. Signed-off-by: Imre Palik <imrep@amazon.de> Cc: Matt Wilson <msw@amazon.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen: netback: read hotplug script once at start of day.Ian Campbell2015-06-011-14/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we come to tear things down in netback_remove() and generate the uevent it is possible that the xenstore directory has already been removed (details below). In such cases netback_uevent() won't be able to read the hotplug script and will write a xenstore error node. A recent change to the hypervisor exposed this race such that we now sometimes lose it (where apparently we didn't ever before). Instead read the hotplug script configuration during setup and use it for the lifetime of the backend device. The apparently more obvious fix of moving the transition to state=Closed in netback_remove() to after the uevent does not work because it is possible that we are already in state=Closed (in reaction to the guest having disconnected as it shutdown). Being already in Closed means the toolstack is at liberty to start tearing down the xenstore directories. In principal it might be possible to arrange to unregister the device sooner (e.g on transition to Closing) such that xenstore would still be there but this state machine is fragile and prone to anger... A modern Xen system only relies on the hotplug uevent for driver domains, when the backend is in the same domain as the toolstack it will run the necessary setup/teardown directly in the correct sequence wrt xenstore changes. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen/netback: Properly initialize credit_bytesRoss Lagerwall2015-05-271-0/+1
| | | | | | | | | | | | Commit e9ce7cb6b107 ("xen-netback: Factor queue-specific data into queue struct") introduced a regression when moving queue-specific data into the queue struct by failing to set the credit_bytes field. This prevented bandwidth limiting from working. Initialize the field as it was done before multiqueue support was added. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: making the bandwidth limiter runtime settablePalik, Imre2015-03-201-0/+57
| | | | | | | | | | | | | | With the current netback, the bandwidth limiter's parameters are only settable during vif setup time. This patch register a watch on them, and thus makes them runtime changeable. When the watch fires, the timer is reset. The timer's mutex is used for fencing the change. Cc: Anthony Liguori <aliguori@amazon.com> Signed-off-by: Imre Palik <imrep@amazon.de> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: fixing the propagation of the transmit shaper timeoutPalik, Imre2015-01-061-0/+1
| | | | | | | | | | | | | Since e9ce7cb6b107 ("xen-netback: Factor queue-specific data into queue struct"), the transimt shaper timeout is always set to 0. The value the user sets via xenbus is never propagated to the transmit shaper. This patch fixes the issue. Cc: Anthony Liguori <aliguori@amazon.com> Signed-off-by: Imre Palik <imrep@amazon.de> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: support frontends without feature-rx-notify againDavid Vrabel2014-12-181-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit bc96f648df1bbc2729abbb84513cf4f64273a1f1 (xen-netback: make feature-rx-notify mandatory) incorrectly assumed that there were no frontends in use that did not support this feature. But the frontend driver in MiniOS does not and since this is used by (qemu) stubdoms, these stopped working. Netback sort of works as-is in this mode except: - If there are no Rx requests and the internal Rx queue fills, only the drain timeout will wake the thread. The default drain timeout of 10 s would give unacceptable pauses. - If an Rx stall was detected and the internal Rx queue is drained, then the Rx thread would never wake. Handle these two cases (when feature-rx-notify is disabled) by: - Reducing the drain timeout to 30 ms. - Disabling Rx stall detection. Reported-by: John <jw@nuclearfallout.net> Tested-by: John <jw@nuclearfallout.net> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netback: don't store invalid vif pointerJan Beulich2014-12-091-4/+5
| | | | | | | | | | When xenvif_alloc() fails, it returns a non-NULL error indicator. To avoid eventual races, we shouldn't store that into struct backend_info as readers of it only check for NULL. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: do not report success if backend_create_xenvif() failsAlexey Khoroshilov2014-11-241-6/+9
| | | | | | | | | | | | | If xenvif_alloc() or xenbus_scanf() fail in backend_create_xenvif(), xenbus is left in offline mode but netback_probe() reports success. The patch implements propagation of error code for backend_create_xenvif(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: reintroduce guest Rx stall detectionDavid Vrabel2014-10-251-0/+1
| | | | | | | | | | | | | | | | | | | | If a frontend not receiving packets it is useful to detect this and turn off the carrier so packets are dropped early instead of being queued and drained when they expire. A to-guest queue is stalled if it doesn't have enough free slots for a an extended period of time (default 60 s). If at least one queue is stalled, the carrier is turned off (in the expectation that the other queues will soon stall as well). The carrier is only turned on once all queues are ready. When the frontend connects, all the queues start in the stalled state and only become ready once the frontend queues enough Rx requests. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: fix unlimited guest Rx internal queue and carrier flappingDavid Vrabel2014-10-251-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Netback needs to discard old to-guest skb's (guest Rx queue drain) and it needs detect guest Rx stalls (to disable the carrier so packets are discarded earlier), but the current implementation is very broken. 1. The check in hard_start_xmit of the slot availability did not consider the number of packets that were already in the guest Rx queue. This could allow the queue to grow without bound. The guest stops consuming packets and the ring was allowed to fill leaving S slot free. Netback queues a packet requiring more than S slots (ensuring that the ring stays with S slots free). Netback queue indefinately packets provided that then require S or fewer slots. 2. The Rx stall detection is not triggered in this case since the (host) Tx queue is not stopped. 3. If the Tx queue is stopped and a guest Rx interrupt occurs, netback will consider this an Rx purge event which may result in it taking the carrier down unnecessarily. It also considers a queue with only 1 slot free as unstalled (even though the next packet might not fit in this). The internal guest Rx queue is limited by a byte length (to 512 Kib, enough for half the ring). The (host) Tx queue is stopped and started based on this limit. This sets an upper bound on the amount of memory used by packets on the internal queue. This allows the estimatation of the number of slots for an skb to be removed (it wasn't a very good estimate anyway). Instead, the guest Rx thread just waits for enough free slots for a maximum sized packet. skbs queued on the internal queue have an 'expires' time (set to the current time plus the drain timeout). The guest Rx thread will detect when the skb at the head of the queue has expired and discard expired skbs. This sets a clear upper bound on the length of time an skb can be queued for. For a guest being destroyed the maximum time needed to wait for all the packets it sent to be dropped is still the drain timeout (10 s) since it will not be sending new packets. Rx stall detection is reintroduced in a later commit. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: make feature-rx-notify mandatoryDavid Vrabel2014-10-251-9/+4
| | | | | | | | | | | | | Frontends that do not provide feature-rx-notify may stall because netback depends on the notification from frontend to wake the guest Rx thread (even if can_queue is false). This could be fixed but feature-rx-notify was introduced in 2006 and I am not aware of any frontends that do not implement this. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen: remove DEFINE_XENBUS_DRIVER() macroDavid Vrabel2014-10-061-7/+3
| | | | | | | | | | The DEFINE_XENBUS_DRIVER() macro looks a bit weird and causes sparse errors. Replace the uses with standard structure definitions instead. This is similar to pci and usb device registration. Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen-netback: fix debugfs entry creationWei Liu2014-08-131-4/+4
| | | | | | | | | | The original code is bogus. The function gets called in a loop which leaks entries created in previous rounds. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Cc: Zoltan Kiss <zoltan.kiss@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: fix debugfs write length checkWei Liu2014-08-131-3/+6
| | | | | | | | | | | | | | Enlarge buffer size and check input length properly, so that we don't misuse -ENOSPC. Note that command like "kickXXXX" is still allowed, that's one patch for another day if we really want to be very strict on this. Reported-by: SeeChen Ng <seechen81@gmail.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Cc: Zoltan Kiss <zoltan.kiss@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: Adding debugfs "io_ring_qX" filesZoltan Kiss2014-07-081-1/+177
| | | | | | | | | | | | | | | | This patch adds debugfs capabilities to netback. There used to be a similar patch floating around for classic kernel, but it used procfs. It is based on a very similar blkback patch. It creates xen-netback/[vifname]/io_ring_q[queueno] files, reading them output various ring variables etc. Writing "kick" into it imitates an interrupt happened, it can be useful to check whether the ring is just stalled due to a missed interrupt. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: xen-devel@lists.xenproject.org Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: bookkeep number of active queues in our own moduleWei Liu2014-06-251-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original code uses netdev->real_num_tx_queues to bookkeep number of queues and invokes netif_set_real_num_tx_queues to set the number of queues. However, netif_set_real_num_tx_queues doesn't allow real_num_tx_queues to be smaller than 1, which means setting the number to 0 will not work and real_num_tx_queues is untouched. This is bogus when xenvif_free is invoked before any number of queues is allocated. That function needs to iterate through all queues to free resources. Using the wrong number of queues results in NULL pointer dereference. So we bookkeep the number of queues in xen-netback to solve this problem. This fixes a regression introduced by multiqueue patchset in 3.16-rc1. There's another bug in original code that the real number of RX queues is never set. In current Xen multiqueue design, the number of TX queues and RX queues are in fact the same. We need to set the numbers of TX and RX queues to the same value. Also remove xenvif_select_queue and leave queue selection to core driver, as suggested by David Miller. Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> CC: Ian Campbell <ian.campbell@citrix.com> CC: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: Add support for multiple queuesAndrew J. Bennieston2014-06-041-12/+89
| | | | | | | | | | | | | | | | | | Builds on the refactoring of the previous patch to implement multiple queues between xen-netfront and xen-netback. Writes the maximum supported number of queues into XenStore, and reads the values written by the frontend to determine how many queues to use. Ring references and event channels are read from XenStore on a per-queue basis and rings are connected accordingly. Also adds code to handle the cleanup of any already initialised queues if the initialisation of a subsequent queue fails. Signed-off-by: Andrew J. Bennieston <andrew.bennieston@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: Factor queue-specific data into queue structWei Liu2014-06-041-24/+71
| | | | | | | | | | | | | | | | | | | In preparation for multi-queue support in xen-netback, move the queue-specific data from struct xenvif into struct xenvif_queue, and update the rest of the code to use this. Also adds loops over queues where appropriate, even though only one is configured at this point, and uses alloc_netdev_mq() and the corresponding multi-queue netif wake/start/stop functions in preparation for multiple active queues. Finally, implements a trivial queue selection function suitable for ndo_select_queue, which simply returns 0 for a single queue and uses skb_get_hash() to compute the queue index otherwise. Signed-off-by: Andrew J. Bennieston <andrew.bennieston@citrix.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* drivers/net/*: Fix FSF address in file headersJeff Kirsher2013-12-061-2/+1
| | | | | | | | | | | | | | | | | | | | | Several files refer to an old address for the Free Software Foundation in the file header comment. Resolve by replacing the address with the URL <http://www.gnu.org/licenses/> so that we do not have to keep updating the header comments anytime the address changes. CC: Jay Vosburgh <fubar@us.ibm.com> CC: Veaceslav Falico <vfalico@redhat.com> CC: Andy Gospodarek <andy@greyhouse.net> CC: Haiyang Zhang <haiyangz@microsoft.com> CC: "K. Y. Srinivasan" <kys@microsoft.com> CC: Paul Mackerras <paulus@samba.org> CC: Ian Campbell <ian.campbell@citrix.com> CC: Wei Liu <wei.liu2@citrix.com> CC: Rusty Russell <rusty@rustcorp.com.au> CC: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: enable IPv6 TCP GSO to the guestPaul Durrant2013-10-171-2/+27
| | | | | | | | | | | | | This patch adds code to handle SKB_GSO_TCPV6 skbs and construct appropriate extra or prefix segments to pass the large packet to the frontend. New xenstore flags, feature-gso-tcpv6 and feature-gso-tcpv6-prefix, are sampled to determine if the frontend is capable of handling such packets. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: handle IPv6 TCP GSO packets from the guestPaul Durrant2013-10-171-0/+7
| | | | | | | | | | | | | This patch adds a xenstore feature flag, festure-gso-tcpv6, to advertise that netback can handle IPv6 TCP GSO packets. It creates SKB_GSO_TCPV6 skbs if the frontend passes an extra segment with the new type XEN_NETIF_GSO_TYPE_TCPV6 added to netif.h. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: add support for IPv6 checksum offload from guestPaul Durrant2013-10-171-0/+9
| | | | | | | | | | | | | | For performance of VM to VM traffic on a single host it is better to avoid calculation of TCP/UDP checksum in the sending frontend. To allow this this patch adds the code necessary to set up partial checksum for IPv6 packets and xenstore flag feature-ipv6-csum-offload to advertise that fact to frontends. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: add support for IPv6 checksum offload to guestPaul Durrant2013-10-171-1/+6
| | | | | | | | | | | Check xenstore flag feature-ipv6-csum-offload to determine if a guest is happy to accept IPv6 packets with only partial checksum. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: transition to CLOSED when removing a VIFDavid Vrabel2013-10-081-0/+4
| | | | | | | | | | | | | | | | | | | | | If a guest is destroyed without transitioning its frontend to CLOSED, the domain becomes a zombie as netback was not grant unmapping the shared rings. When removing a VIF, transition the backend to CLOSED so the VIF is disconnected if necessary (which will unmap the shared rings etc). This fixes a regression introduced by 279f438e36c0a70b23b86d2090aeec50155034a9 (xen-netback: Don't destroy the netdev until the vif is shut down). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Paul Durrant <Paul.Durrant@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: Handle backend state transitions in a more robust wayPaul Durrant2013-09-301-30/+118
| | | | | | | | | | | | | | | | When the frontend state changes netback now specifies its desired state to a new function, set_backend_state(), which transitions through any necessary intermediate states. This fixes an issue observed with some old Windows frontend drivers where they failed to transition through the Closing state and netback would not behave correctly. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: Don't destroy the netdev until the vif is shut downPaul Durrant2013-09-191-5/+12
| | | | | | | | | | | | | | | | | | | | | Without this patch, if a frontend cycles through states Closing and Closed (which Windows frontends need to do) then the netdev will be destroyed and requires re-invocation of hotplug scripts to restore state before the frontend can move to Connected. Thus when udev is not in use the backend gets stuck in InitWait. With this patch, the netdev is left alone whilst the backend is still online and is only de-registered and freed just prior to destroying the vif (which is also nicely symmetrical with the netdev allocation and registration being done during probe) so no re-invocation of hotplug scripts is required. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: xenbus.c: use more current logging stylesWei Liu2013-07-021-5/+4
| | | | | | | | | | | Convert one printk to pr_<level>. Add a missing newline in several places to avoid message interleaving, coalesce formats, reflow modified lines to 80 columns. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen-netback: split event channels support for Xen backend driverWei Liu2013-05-231-7/+34
| | | | | | | | | | | | | | | 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>
* xen-netback: enable user to unload netback moduleWei Liu2013-05-171-0/+5
| | | | | | | | | | | | | | 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>
* Xen: consolidate and simplify struct xenbus_driver instantiationJan Beulich2012-01-041-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | The 'name', 'owner', and 'mod_name' members are redundant with the identically named fields in the 'driver' sub-structure. Rather than switching each instance to specify these fields explicitly, introduce a macro to simplify this. Eliminate further redundancy by allowing the drvname argument to DEFINE_XENBUS_DRIVER() to be blank (in which case the first entry from the ID table will be used for .driver.name). Also eliminate the questionable xenbus_register_{back,front}end() wrappers - their sole remaining purpose was the checking of the 'owner' field, proper setting of which shouldn't be an issue anymore when the macro gets used. v2: Restore DRV_NAME for the driver name in xen-pciback. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* Signed bit field; int have_hotplug_status_watch:1Ian Campbell2011-04-061-1/+1
| | | | | | | | | | | | Fixes error from sparse: CHECK drivers/net/xen-netback/xenbus.c drivers/net/xen-netback/xenbus.c:29:40: error: dubious one-bit signed bitfield int have_hotplug_status_watch:1; Reported-by: Dr. David Alan Gilbert <linux@treblig.org> Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xen network backend driverIan Campbell2011-03-151-0/+490
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 2e820f58f7ad "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>
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