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path: root/drivers/net/xen-netback/xenbus.c
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2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-01xen networking: add XDP offset adjustment to xen-netbackDenis Kirjanov
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>
2019-12-26xen-netback: support dynamic unbind/bindPaul Durrant
By re-attaching RX, TX, and CTL rings during connect() rather than assuming they are freshly allocated (i.e. assuming the counters are zero), and avoiding forcing state to Closed in netback_remove() it is possible for vif instances to be unbound and re-bound from and to (respectively) a running guest. Dynamic unbind/bind is a highly useful feature for a backend module as it allows it to be unloaded and re-loaded (i.e. updated) without requiring domUs to be halted. This has been tested by running iperf as a server in the test VM and then running a client against it in a continuous loop, whilst also running: while true; do echo vif-$DOMID-$VIF >unbind; echo down; rmmod xen-netback; echo unloaded; modprobe xen-netback; cd $(pwd); brctl addif xenbr0 vif$DOMID.$VIF; ip link set vif$DOMID.$VIF up; echo up; sleep 5; done in dom0 from /sys/bus/xen-backend/drivers/vif to continuously unbind, unload, re-load, re-bind and re-plumb the backend. Clearly a performance drop was seen but no TCP connection resets were observed during this test and moreover a parallel SSH connection into the guest remained perfectly usable throughout. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17xen-netback: remove 'hotplug-status' once it has served its purposePaul Durrant
Removing the 'hotplug-status' node in netback_remove() is wrong; the script may not have completed. Only remove the node once the watch has fired and has been unregistered. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Acked-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17xen-netback: switch state to InitWait at the end of netback_probe()...Paul Durrant
...as the comment above the function states. The switch to Initialising at the start of the function is somewhat bogus as the toolstack will have set that initial state anyway. To behave correctly, a backend should switch to InitWait once it has set up all xenstore values that may be required by a initialising frontend. This patch calls backend_switch_state() to make the transition at the appropriate point. NOTE: backend_switch_state() ignores errors from xenbus_switch_state() and so this patch removes an error path from netback_probe(). This means a failure to change state at this stage (in the absence of other failures) will leave the device instantiated. This is highly unlikley to happen as a failure to change state would indicate a failure to write to xenstore, and that will trigger other error paths. Also, a 'stuck' device can still be cleaned up using 'unbind' in any case. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Acked-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17xen-netback: move netback_probe() and netback_remove() to the end...Paul Durrant
...of xenbus.c This is a cosmetic function re-ordering to reduce churn in a subsequent patch. Some style fix-up was done to make checkpatch.pl happier. No functional change. Signed-off-by: Paul Durrant <pdurrant@amazon.com> Acked-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-11xen-netback: no need to check return value of debugfs_create functionsGreg Kroah-Hartman
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: Wei Liu <wei.liu@kernel.org> Cc: Paul Durrant <paul.durrant@citrix.com> Cc: xen-devel@lists.xenproject.org Cc: netdev@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-21treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13Thomas Gleixner
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details [based] [from] [clk] [highbank] [c] you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 355 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154041.837383322@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-12xen-netback: add reference from xenvif to backend_info to facilitate ↵Dongli Zhang
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>
2019-02-08xen-netback: mark expected switch fall-throughGustavo A. R. Silva
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Warning level 3 was used: -Wimplicit-fallthrough=3 This patch is part of the ongoing efforts to enabling -Wimplicit-fallthrough. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-10net: xenbus: convert to DEFINE_SHOW_ATTRIBUTEYangtao Li
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-11net: xenbus: remove redundant condition check before debugfs_remove_recursivezhong jiang
debugfs_remove_recursive has taken the IS_ERR_OR_NULL into account. Just remove the unnecessary condition check. Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-12treewide: Use array_size() in vzalloc()Kees Cook
The vzalloc() function has no 2-factor argument form, so multiplication factors need to be wrapped in array_size(). This patch replaces cases of: vzalloc(a * b) with: vzalloc(array_size(a, b)) as well as handling cases of: vzalloc(a * b * c) with: vzalloc(array3_size(a, b, c)) This does, however, attempt to ignore constant size factors like: vzalloc(4 * 1024) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( vzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | vzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( vzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(u8) * COUNT + COUNT , ...) | vzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | vzalloc( - sizeof(char) * COUNT + COUNT , ...) | vzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( vzalloc( - sizeof(TYPE) * (COUNT_ID) + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT_ID + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT_CONST + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vzalloc( - sizeof(THING) * (COUNT_ID) + array_size(COUNT_ID, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT_ID + array_size(COUNT_ID, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT_CONST + array_size(COUNT_CONST, sizeof(THING)) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ vzalloc( - SIZE * COUNT + array_size(COUNT, SIZE) , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( vzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( vzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | vzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( vzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( vzalloc(C1 * C2 * C3, ...) | vzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants. @@ expression E1, E2; constant C1, C2; @@ ( vzalloc(C1 * C2, ...) | vzalloc( - E1 * E2 + array_size(E1, E2) , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-03-26drivers/net: Use octal not symbolic permissionsJoe Perches
Prefer the direct use of octal for permissions. Done with checkpatch -f --types=SYMBOLIC_PERMS --fix-inplace and some typing. Miscellanea: o Whitespace neatening around these conversions. Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-12xen-netback: fix race condition on XenBus disconnectIgor Druzhinin
In some cases during XenBus disconnect event handling and subsequent queue resource release there may be some TX handlers active on other processors. Use RCU in order to synchronize with them. Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-03xen-netback: don't vfree() queues under spinlockPaul Durrant
This leads to a BUG of the following form: [ 174.512861] switch: port 2(vif3.0) entered disabled state [ 174.522735] BUG: sleeping function called from invalid context at /home/build/linux-linus/mm/vmalloc.c:1441 [ 174.523451] in_atomic(): 1, irqs_disabled(): 0, pid: 28, name: xenwatch [ 174.524131] CPU: 1 PID: 28 Comm: xenwatch Tainted: G W 4.10.0upstream-11073-g4977ab6-dirty #1 [ 174.524819] Hardware name: MSI MS-7680/H61M-P23 (MS-7680), BIOS V17.0 03/14/2011 [ 174.525517] Call Trace: [ 174.526217] show_stack+0x23/0x60 [ 174.526899] dump_stack+0x5b/0x88 [ 174.527562] ___might_sleep+0xde/0x130 [ 174.528208] __might_sleep+0x35/0xa0 [ 174.528840] ? _raw_spin_unlock_irqrestore+0x13/0x20 [ 174.529463] ? __wake_up+0x40/0x50 [ 174.530089] remove_vm_area+0x20/0x90 [ 174.530724] __vunmap+0x1d/0xc0 [ 174.531346] ? delete_object_full+0x13/0x20 [ 174.531973] vfree+0x40/0x80 [ 174.532594] set_backend_state+0x18a/0xa90 [ 174.533221] ? dwc_scan_descriptors+0x24d/0x430 [ 174.533850] ? kfree+0x5b/0xc0 [ 174.534476] ? xenbus_read+0x3d/0x50 [ 174.535101] ? xenbus_read+0x3d/0x50 [ 174.535718] ? xenbus_gather+0x31/0x90 [ 174.536332] ? ___might_sleep+0xf6/0x130 [ 174.536945] frontend_changed+0x6b/0xd0 [ 174.537565] xenbus_otherend_changed+0x7d/0x80 [ 174.538185] frontend_changed+0x12/0x20 [ 174.538803] xenwatch_thread+0x74/0x110 [ 174.539417] ? woken_wake_function+0x20/0x20 [ 174.540049] kthread+0xe5/0x120 [ 174.540663] ? xenbus_printf+0x50/0x50 [ 174.541278] ? __kthread_init_worker+0x40/0x40 [ 174.541898] ret_from_fork+0x21/0x2c [ 174.548635] switch: port 2(vif3.0) entered disabled state This patch defers the vfree() until after the spinlock is released. Reported-by: Juergen Gross <jgross@suse.com> Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-03xen-netback: keep a local pointer for vif in backend_disconnect()Paul Durrant
This patch replaces use of 'be->vif' with 'vif' and hence generally makes the function look tidier. No semantic change. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-09xen: modify xenstore watch event interfaceJuergen Gross
Today a Xenstore watch event is delivered via a callback function declared as: void (*callback)(struct xenbus_watch *, const char **vec, unsigned int len); As all watch events only ever come with two parameters (path and token) changing the prototype to: void (*callback)(struct xenbus_watch *, const char *path, const char *token); is the natural thing to do. Apply this change and adapt all users. Cc: konrad.wilk@oracle.com Cc: roger.pau@citrix.com Cc: wei.liu2@citrix.com Cc: paul.durrant@citrix.com Cc: netdev@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-01-18xen-netback: protect resource cleaning on XenBus disconnectIgor Druzhinin
vif->lock is used to protect statistics gathering agents from using the queue structure during cleaning. Signed-off-by: Igor Druzhinin <igor.druzhinin@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>
2017-01-18xen-netback: fix memory leaks on XenBus disconnectIgor Druzhinin
Eliminate memory leaks introduced several years ago by cleaning the queue resources which are allocated on XenBus connection event. Namely, queue structure array and pages used for IO rings. Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-13Merge tag 'for-linus-4.10-rc0-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: "Xen features and fixes for 4.10 These are some fixes, a move of some arm related headers to share them between arm and arm64 and a series introducing a helper to make code more readable. The most notable change is David stepping down as maintainer of the Xen hypervisor interface. This results in me sending you the pull requests for Xen related code from now on" * tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (29 commits) xen/balloon: Only mark a page as managed when it is released xenbus: fix deadlock on writes to /proc/xen/xenbus xen/scsifront: don't request a slot on the ring until request is ready xen/x86: Increase xen_e820_map to E820_X_MAX possible entries x86: Make E820_X_MAX unconditionally larger than E820MAX xen/pci: Bubble up error and fix description. xen: xenbus: set error code on failure xen: set error code on failures arm/xen: Use alloc_percpu rather than __alloc_percpu arm/arm64: xen: Move shared architecture headers to include/xen/arm xen/events: use xen_vcpu_id mapping for EVTCHNOP_status xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing xen-scsifront: Add a missing call to kfree MAINTAINERS: update XEN HYPERVISOR INTERFACE xenfs: Use proc_create_mount_point() to create /proc/xen xen-platform: use builtin_pci_driver xen-netback: fix error handling output xen: make use of xenbus_read_unsigned() in xenbus xen: make use of xenbus_read_unsigned() in xen-pciback xen: make use of xenbus_read_unsigned() in xen-fbfront ...
2016-11-10xen-netback: fix error handling outputArnd Bergmann
The connect function prints an unintialized error code after an earlier initialization was removed: drivers/net/xen-netback/xenbus.c: In function 'connect': drivers/net/xen-netback/xenbus.c:938:3: error: 'err' may be used uninitialized in this function [-Werror=maybe-uninitialized] This prints it as -EINVAL instead, which seems to be the most appropriate error code. Before the patch that caused the warning, this would print a positive number returned by vsscanf() instead, which is also wrong. We probably don't need a backport though, as fixing the warning here should be sufficient. Fixes: f95842e7a9f2 ("xen: make use of xenbus_read_unsigned() in xen-netback") Fixes: 8d3d53b3e433 ("xen-netback: Add support for multiple queues") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Juergen Gross <jgross@suse.com>
2016-11-09xen-netback: prefer xenbus_scanf() over xenbus_gather()Jan Beulich
For single items being collected this should be preferred as being more typesafe (as the compiler can check format string and to-be-written-to variable match) and more efficient (requiring one less parameter to be passed). 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>
2016-11-07xen: make use of xenbus_read_unsigned() in xen-netbackJuergen Gross
Use xenbus_read_unsigned() instead of xenbus_scanf() when possible. This requires to change the type of some reads from int to unsigned, but these cases have been wrong before: negative values are not allowed for the modified cases. Cc: wei.liu2@citrix.com Cc: paul.durrant@citrix.com Cc: netdev@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: David Vrabel <david.vrabel@citrix.com>
2016-10-13xen-netback: (re-)create a debugfs node for hash informationPaul Durrant
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: retire guest rx side prefix GSO featurePaul Durrant
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>
2016-09-17xen-netback: fix error handling on netback_probe()Filipe Manco
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>
2016-05-16xen-netback: add control ring boilerplatePaul Durrant
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: reduce log spamPaul Durrant
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>
2016-02-07xen-netback: implement dynamic multicast controlPaul Durrant
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>
2015-10-18xen-netback: correctly check failed allocationInsu Yun
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>
2015-09-02xen-netback: add support for multicast controlPaul Durrant
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>
2015-06-23xen-netback: fix a BUG() during initializationPalik, Imre
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>
2015-06-01xen: netback: read hotplug script once at start of day.Ian Campbell
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>
2015-05-27xen/netback: Properly initialize credit_bytesRoss Lagerwall
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>
2015-03-20xen-netback: making the bandwidth limiter runtime settablePalik, Imre
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>
2015-01-06xen-netback: fixing the propagation of the transmit shaper timeoutPalik, Imre
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>
2014-12-18xen-netback: support frontends without feature-rx-notify againDavid Vrabel
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>
2014-12-09netback: don't store invalid vif pointerJan Beulich
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>
2014-11-24xen-netback: do not report success if backend_create_xenvif() failsAlexey Khoroshilov
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>
2014-10-25xen-netback: reintroduce guest Rx stall detectionDavid Vrabel
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 Vrabel
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 Vrabel
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>
2014-10-06xen: remove DEFINE_XENBUS_DRIVER() macroDavid Vrabel
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>
2014-08-13xen-netback: fix debugfs entry creationWei Liu
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>
2014-08-13xen-netback: fix debugfs write length checkWei Liu
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>
2014-07-08xen-netback: Adding debugfs "io_ring_qX" filesZoltan Kiss
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 Liu
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. Bennieston
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 Liu
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>
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