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path: root/drivers/net/xen-netback/common.h
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2023-03-28xen/netback: don't do grant copy across page boundaryJuergen Gross1-1/+1
Fix xenvif_get_requests() not to do grant copy operations across local page boundaries. This requires to double the maximum number of copy operations per queue, as each copy could now be split into 2. Make sure that struct xenvif_tx_cb doesn't grow too large. Cc: stable@vger.kernel.org Fixes: ad7f402ae4f4 ("xen/netback: Ensure protocol headers don't fall in the non-linear area") Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Paul Durrant <paul@xen.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-12-06xen/netback: don't call kfree_skb() with interrupts disabledJuergen Gross1-1/+1
It is not allowed to call kfree_skb() from hardware interrupt context or with interrupts being disabled. So remove kfree_skb() from the spin_lock_irqsave() section and use the already existing "drop" label in xenvif_start_xmit() for dropping the SKB. At the same time replace the dev_kfree_skb() call there with a call of dev_kfree_skb_any(), as xenvif_start_xmit() can be called with disabled interrupts. This is XSA-424 / CVE-2022-42328 / CVE-2022-42329. Fixes: be81992f9086 ("xen/netback: don't queue unlimited number of packages") Reported-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2022-09-28xen/netback: use struct ubuf_info_msgzcPavel Begunkov1-1/+1
struct ubuf_info will be changed, use ubuf_info_msgzc instead. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-08xen/netback: do some code cleanupJuergen Gross1-12/+0
Remove some unused macros and functions, make local functions static. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20220608043726.9380-1-jgross@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-16xen/netback: fix rx queue stall detectionJuergen Gross1-0/+1
Commit 1d5d48523900a4b ("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: 1d5d48523900a4b ("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>
2021-01-07skbuff: Add skb parameter to the ubuf zerocopy callbackJonathan Lemon1-1/+2
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>
2020-10-20xen/netback: use lateeoi irq bindingJuergen Gross1-0/+15
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>
2020-07-01xen networking: add XDP offset adjustment to xen-netbackDenis Kirjanov1-0/+4
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>
2019-04-12xen-netback: add reference from xenvif to backend_info to facilitate ↵Dongli Zhang1-0/+18
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>
2018-09-25xen-netback: validate queue numbers in xenvif_set_hash_mapping()Jan Beulich1-1/+2
Checking them before the grant copy means nothing as to the validity of the incoming request. As we shouldn't make the new data live before having validated it, introduce a second instance of the mapping array. Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18net/xen-netback: Convert timers to use timer_setup()Kees Cook1-1/+1
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Wei Liu <wei.liu2@citrix.com> Cc: Paul Durrant <paul.durrant@citrix.com> Cc: xen-devel@lists.xenproject.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-22xen-netback: correctly schedule rate-limited queuesWei Liu1-0/+1
Add a flag to indicate if a queue is rate-limited. Test the flag in NAPI poll handler and avoid rescheduling the queue if true, otherwise we risk locking up the host. The rescheduling will be done in the timer callback function. Reported-by: Jean-Louis Dupond <jean-louis@dupond.be> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Tested-by: Jean-Louis Dupond <jean-louis@dupond.be> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-13xen-netback: vif counters from int/long to u64Mart van Santen1-4/+4
This patch fixes an issue where the type of counters in the queue(s) and interface are not in sync (queue counters are int, interface counters are long), causing incorrect reporting of tx/rx values of the vif interface and unclear counter overflows. This patch sets both counters to the u64 type. Signed-off-by: Mart van Santen <mart@greenhost.nl> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-13xen-netback: (re-)create a debugfs node for hash informationPaul Durrant1-0/+4
It is useful to be able to see the hash configuration when running tests. This patch adds a debugfs node for that purpose. The original version of this patch (commit c0c64c152389) was reverted due to build failures caused by a conflict with commit 0364a8824c02 ("xen-netback: switch to threaded irq for control ring"). This new version of the patch is nearly identical to the original, the only difference being that creation of the debugfs node is predicated on 'ctrl_irq' being non-zero rather then the now non-existent 'ctrl_task'. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David S. Miller <davem@davemloft.net> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-06xen-netback: batch copies for multiple to-guest rx packetsDavid Vrabel1-0/+1
Instead of flushing the copy ops when an packet is complete, complete packets when their copy ops are done. This improves performance by reducing the number of grant copy hypercalls. Latency is still limited by the relatively small size of the copy batch. Signed-off-by: David Vrabel <david.vrabel@citrix.com> [re-based] Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-06xen-netback: refactor guest rxDavid Vrabel1-13/+10
Refactor the to-guest (rx) path to: 1. Push responses for completed skbs earlier, reducing latency. 2. Reduce the per-queue memory overhead by greatly reducing the maximum number of grant copy ops in each hypercall (from 4352 to 64). Each struct xenvif_queue is now only 44 kB instead of 220 kB. 3. Make the code more maintainable. Signed-off-by: David Vrabel <david.vrabel@citrix.com> [re-based] Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-06xen-netback: retire guest rx side prefix GSO featurePaul Durrant1-1/+0
As far as I am aware only very old Windows network frontends make use of this style of passing GSO packets from backend to frontend. These frontends can easily be replaced by the freely available Xen Project Windows PV network frontend, which uses the 'default' mechanism for passing GSO packets, which is also used by all Linux frontends. NOTE: Removal of this feature will not cause breakage in old Windows frontends. They simply will no longer receive GSO packets - the packets instead being fragmented in the backend. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-23Revert "xen-netback: create a debugfs node for hash information"David S. Miller1-4/+0
This reverts commit c0c64c152389ad73306b9b0796357210ec6d32ee. There is no vif->ctrl_task member, so this change broke the build. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-22xen-netback: switch to threaded irq for control ringJuergen Gross1-3/+1
Instead of open coding it use the threaded irq mechanism in xen-netback. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-18xen-netback: create a debugfs node for hash informationPaul Durrant1-0/+4
It is useful to be able to see the hash configuration when running tests. This patch adds a debugfs node for that purpose. 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>
2016-05-16xen-netback: add control protocol implementationPaul Durrant1-0/+46
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. A previous patch added the necessary boilerplate for mapping the control ring from the frontend, should it be created. This patch adds implementations for each of the defined protocol messages. 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>
2016-05-16xen-netback: add control ring boilerplatePaul Durrant1-8/+20
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>
2016-03-13xen-netback: support multiple extra info fragments passed from frontendPaul Durrant1-0/+1
The code does not currently support a frontend passing multiple extra info fragments to the backend in a tx request. The xenvif_get_extras() function handles multiple extra_info fragments but make_tx_response() assumes there is only ever a single extra info fragment. This patch modifies xenvif_get_extras() to pass back a count of extra info fragments, which is then passed to make_tx_response() (after possibly being stashed in pending_tx_info for deferred responses). 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>
2016-02-07xen-netback: implement dynamic multicast controlPaul Durrant1-0/+1
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>
2015-10-23net/xen-netback: Make it running on 64KB page granularityJulien Grall1-5/+11
The PV network protocol is using 4KB page granularity. The goal of this patch is to allow a Linux using 64KB page granularity working as a network backend 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. Signed-off-by: Julien Grall <julien.grall@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-09-09xen-netback: require fewer guest Rx slots when not using GSODavid Vrabel1-10/+0
Commit f48da8b14d04ca87ffcffe68829afd45f926ec6a (xen-netback: fix unlimited guest Rx internal queue and carrier flapping) introduced a regression. The PV frontend in IPXE only places 4 requests on the guest Rx ring. Since netback required at least (MAX_SKB_FRAGS + 1) slots, IPXE could not receive any packets. a) If GSO is not enabled on the VIF, fewer guest Rx slots are required for the largest possible packet. Calculate the required slots based on the maximum GSO size or the MTU. This calculation of the number of required slots relies on 1650d5455bd2 (xen-netback: always fully coalesce guest Rx packets) which present in 4.0-rc1 and later. b) Reduce the Rx stall detection to checking for at least one available Rx request. This is fine since we're predominately concerned with detecting interfaces which are down and thus have zero available 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>
2015-09-02xen-netback: add support for multicast controlPaul Durrant1-0/+15
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>
2015-07-08xen-netback: remove duplicated function definitionLi, Liang Z1-3/+0
There are two duplicated xenvif_zerocopy_callback() definitions. Remove one of them. Signed-off-by: Liang Li <liang.z.li@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20xen-netback: making the bandwidth limiter runtime settablePalik, Imre1-0/+4
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>
2015-01-23xen-netback: always fully coalesce guest Rx packetsDavid Vrabel1-1/+0
Always fully coalesce guest Rx packets into the minimum number of ring slots. Reducing the number of slots per packet has significant performance benefits when receiving off-host traffic. Results from XenServer's performance benchmarks: Baseline Full coalesce Interhost VM receive 7.2 Gb/s 11 Gb/s Interhost aggregate 24 Gb/s 24 Gb/s Intrahost single stream 14 Gb/s 14 Gb/s Intrahost aggregate 34 Gb/s 34 Gb/s However, this can increase the number of grant ops per packet which decreases performance of backend (dom0) to VM traffic (by ~10%) /unless/ grant copy has been optimized for adjacent ops with the same source or destination (see "grant-table: defer releasing pages acquired in a grant copy"[1] expected in Xen 4.6). [1] http://lists.xen.org/archives/html/xen-devel/2015-01/msg01118.html Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-18xen-netback: support frontends without feature-rx-notify againDavid Vrabel1-1/+3
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>
2014-10-25xen-netback: reintroduce guest Rx stall detectionDavid Vrabel1-0/+5
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>
2014-10-25xen-netback: fix unlimited guest Rx internal queue and carrier flappingDavid Vrabel1-12/+17
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>
2014-10-25xen-netback: make feature-rx-notify mandatoryDavid Vrabel1-5/+0
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>
2014-08-13xen-netback: don't stop dealloc kthread too earlyWei Liu1-0/+5
Reference count the number of packets in host stack, so that we don't stop the deallocation thread too early. If not, we can end up with xenvif_free permanently waiting for deallocation thread to unmap grefs. Reported-by: Thomas Leonard <talex5@gmail.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-05xen-netback: Turn off the carrier if the guest is not able to receiveZoltan Kiss1-3/+12
Currently when the guest is not able to receive more packets, qdisc layer starts a timer, and when it goes off, qdisc is started again to deliver a packet again. This is a very slow way to drain the queues, consumes unnecessary resources and slows down other guests shutdown. This patch change the behaviour by turning the carrier off when that timer fires, so all the packets are freed up which were stucked waiting for that vif. Instead of the rx_queue_purge bool it uses the VIF_STATUS_RX_PURGE_EVENT bit to signal the thread that either the timeout happened or an RX interrupt arrived, so the thread can check what it should do. It also disables NAPI, so the guest can't transmit, but leaves the interrupts on, so it can resurrect. Only the queues which brought down the interface can enable it again, the bit QUEUE_STATUS_RX_STALLED makes sure of that. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David Vrabel <david.vrabel@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>
2014-08-05xen-netback: Using a new state bit instead of carrierZoltan Kiss1-0/+6
This patch introduces a new state bit VIF_STATUS_CONNECTED to track whether the vif is in a connected state. Using carrier will not work with the next patch in this series, which aims to turn the carrier temporarily off if the guest doesn't seem to be able to receive packets. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: xen-devel@lists.xenproject.org v2: - rename the bitshift type to "enum state_bit_shift" here, not in the next patch Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-08xen-netback: Adding debugfs "io_ring_qX" filesZoltan Kiss1-0/+11
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>
2014-06-25xen-netback: bookkeep number of active queues in our own moduleWei Liu1-0/+1
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>
2014-06-04xen-netback: Add support for multiple queuesAndrew J. Bennieston1-0/+2
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>
2014-06-04xen-netback: Factor queue-specific data into queue structWei Liu1-33/+69
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>
2014-06-04xen-netback: Move grant_copy_op array back into struct xenvif.Andrew J. Bennieston1-2/+1
This array was allocated separately in commit ac3d5ac2 ("xen-netback: fix guest-receive-side array sizes") due to it being very large, and a struct xenvif is allocated as the netdev_priv part of a struct net_device, i.e. via kmalloc() but falling back to vmalloc() if the initial alloc. fails. In preparation for the multi-queue patches, where this array becomes part of struct xenvif_queue and is always allocated through vzalloc(), move this back into the struct xenvif. 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>
2014-05-16xen-netback: fix race between napi_complete() and interrupt handlerDavid Vrabel1-1/+1
When the NAPI budget was not all used, xenvif_poll() would call napi_complete() /after/ enabling the interrupt. This resulted in a race between the napi_complete() and the napi_schedule() in the interrupt handler. The use of local_irq_save/restore() avoided by race iff the handler is running on the same CPU but not if it was running on a different CPU. Fix this properly by calling napi_complete() before reenabling interrupts (in the xenvif_napi_schedule_or_enable_irq() call). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-03xen-netback: Grant copy the header instead of map and memcpyZoltan Kiss1-0/+1
An old inefficiency of the TX path that we are grant mapping the first slot, and then copy the header part to the linear area. Instead, doing a grant copy for that header straight on is more reasonable. Especially because there are ongoing efforts to make Xen avoiding TLB flush after unmap when the page were not touched in Dom0. In the original way the memcpy ruined that. The key changes: - the vif has a tx_copy_ops array again - xenvif_tx_build_gops sets up the grant copy operations - we don't have to figure out whether the header and first frag are on the same grant mapped page or not Note, we only grant copy PKT_PROT_LEN bytes from the first slot, the rest (if any) will be on the first frag, which is grant mapped. If the first slot is smaller than PKT_PROT_LEN, then we grant copy that, and later __pskb_pull_tail will pull more from the frags (if any) Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-01xen-netback: disable rogue vif in kthread contextWei Liu1-0/+5
When netback discovers frontend is sending malformed packet it will disables the interface which serves that frontend. However disabling a network interface involving taking a mutex which cannot be done in softirq context, so we need to defer this process to kthread context. This patch does the following: 1. introduce a flag to indicate the interface is disabled. 2. check that flag in TX path, don't do any work if it's true. 3. check that flag in RX path, turn off that interface if it's true. The reason to disable it in RX path is because RX uses kthread. After this change the behavior of netback is still consistent -- it won't do any TX work for a rogue frontend, and the interface will be eventually turned off. Also change a "continue" to "break" after xenvif_fatal_tx_err, as it doesn't make sense to continue processing packets if frontend is rogue. This is a fix for XSA-90. Reported-by: Török Edwin <edwin@etorok.net> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-26xen-netback: Stop using xenvif_tx_pending_slots_availableZoltan Kiss1-7/+1
Since the early days TX stops if there isn't enough free pending slots to consume a maximum sized (slot-wise) packet. Probably the reason for that is to avoid the case when we don't have enough free pending slot in the ring to finish the packet. But if we make sure that the pending ring has the same size as the shared ring, that shouldn't really happen. The frontend can only post packets which fit the to the free space of the shared ring. If it doesn't, the frontend has to stop, as it can only increase the req_prod when the whole packet fits onto the ring. This patch avoid using this checking, makes sure the 2 ring has the same size, and remove a checking from the callback. As now we don't stop the NAPI instance on this condition, we don't have to wake it up if we free pending slots up. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-25Revert "xen-netback: Aggregate TX unmap operations"Zoltan Kiss1-2/+0
This reverts commit e9275f5e2df1b2098a8cc405d87b88b9affd73e6. This commit is the last in the netback grant mapping series, and it tries to do more aggressive aggreagtion of unmap operations. However practical use showed almost no positive effect, whilst with certain frontends it causes significant performance regression. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-07xen-netback: Aggregate TX unmap operationsZoltan Kiss1-0/+2
Unmapping causes TLB flushing, therefore we should make it in the largest possible batches. However we shouldn't starve the guest for too long. So if the guest has space for at least two big packets and we don't have at least a quarter ring to unmap, delay it for at most 1 milisec. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-07xen-netback: Timeout packets in RX pathZoltan Kiss1-0/+6
A malicious or buggy guest can leave its queue filled indefinitely, in which case qdisc start to queue packets for that VIF. If those packets came from an another guest, it can block its slots and prevent shutdown. To avoid that, we make sure the queue is drained in every 10 seconds. The QDisc queue in worst case takes 3 round to flush usually. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-07xen-netback: Handle guests with too many fragsZoltan Kiss1-0/+1
Xen network protocol had implicit dependency on MAX_SKB_FRAGS. Netback has to handle guests sending up to XEN_NETBK_LEGACY_SLOTS_MAX slots. To achieve that: - create a new skb - map the leftover slots to its frags (no linear buffer here!) - chain it to the previous through skb_shinfo(skb)->frag_list - map them - copy and coalesce the frags into a brand new one and send it to the stack - unmap the 2 old skb's pages It's also introduces new stat counters, which help determine how often the guest sends a packet with more than MAX_SKB_FRAGS frags. NOTE: if bisect brought you here, you should apply the series up until "xen-netback: Timeout packets in RX path", otherwise malicious guests can block other guests by not releasing their sent packets. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>