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2020-10-23xen/events: make struct irq_info private to events_base.cJuergen Gross
The struct irq_info of Xen's event handling is used only for two evtchn_ops functions outside of events_base.c. Those two functions can easily be switched to avoid that usage. This allows to make struct irq_info and its related access functions private to events_base.c. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Link: https://lore.kernel.org/r/20201022094907.28560-3-jgross@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2020-10-20xen/events: defer eoi in case of excessive number of eventsJuergen Gross
In case rogue guests are sending events at high frequency it might happen that xen_evtchn_do_upcall() won't stop processing events in dom0. As this is done in irq handling a crash might be the result. In order to avoid that, delay further inter-domain events after some time in xen_evtchn_do_upcall() by forcing eoi processing into a worker on the same cpu, thus inhibiting new events coming in. The time after which eoi processing is to be delayed is configurable via a new module parameter "event_loop_timeout" which specifies the maximum event loop time in jiffies (default: 2, the value was chosen after some tests showing that a value of 2 was the lowest with an only slight drop of dom0 network throughput while multiple guests performed an event storm). How long eoi processing will be delayed can be specified via another parameter "event_eoi_delay" (again in jiffies, default 10, again the value was chosen after testing with different delay values). 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: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Wei Liu <wl@xen.org>
2020-10-20xen/events: add a proper barrier to 2-level uevent unmaskingJuergen Gross
A follow-up patch will require certain write to happen before an event channel is unmasked. While the memory barrier is not strictly necessary for all the callers, the main one will need it. In order to avoid an extra memory barrier when using fifo event channels, mandate evtchn_unmask() to provide write ordering. The 2-level event handling unmask operation is missing an appropriate barrier, so add it. Fifo event channels are fine in this regard due to using sync_cmpxchg(). This is part of XSA-332. Cc: stable@vger.kernel.org Suggested-by: Julien Grall <julien@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Julien Grall <jgrall@amazon.com> Reviewed-by: Wei Liu <wl@xen.org>
2020-04-07xen: Use evtchn_type_t as a type for event channelsYan Yankovskyi
Make event channel functions pass event channel port using evtchn_port_t type. It eliminates signed <-> unsigned conversion. Signed-off-by: Yan Yankovskyi <yyankovskyi@gmail.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20200323152343.GA28422@kbp1-lhp-F74019 Signed-off-by: Juergen Gross <jgross@suse.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-22Merge tag 'for-linus-4.6-rc0-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from David Vrabel: "Features and fixes for 4.6: - Make earlyprintk=xen work for HVM guests - Remove module support for things never built as modules" * tag 'for-linus-4.6-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: drivers/xen: make platform-pci.c explicitly non-modular drivers/xen: make sys-hypervisor.c explicitly non-modular drivers/xen: make xenbus_dev_[front/back]end explicitly non-modular drivers/xen: make [xen-]ballon explicitly non-modular xen: audit usages of module.h ; remove unnecessary instances xen/x86: Drop mode-selecting ifdefs in startup_xen() xen/x86: Zero out .bss for PV guests hvc_xen: make early_printk work with HVM guests hvc_xen: fix xenboot for DomUs hvc_xen: add earlycon support
2016-03-21xen: audit usages of module.h ; remove unnecessary instancesPaul Gortmaker
Code that uses no modular facilities whatsoever should not be sourcing module.h at all, since that header drags in a bunch of other headers with it. Similarly, code that is not explicitly using modular facilities like module_init() but only is declaring module_param setup variables should be using moduleparam.h and not the larger module.h file for that. In making this change, we also uncover an implicit use of BUG() in inline fcns within arch/arm/include/asm/xen/hypercall.h so we explicitly source <linux/bug.h> for that file now. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2016-03-15tags: Fix DEFINE_PER_CPU expansionsPeter Zijlstra
$ make tags GEN tags ctags: Warning: drivers/acpi/processor_idle.c:64: null expansion of name pattern "\1" ctags: Warning: drivers/xen/events/events_2l.c:41: null expansion of name pattern "\1" ctags: Warning: kernel/locking/lockdep.c:151: null expansion of name pattern "\1" ctags: Warning: kernel/rcu/rcutorture.c:133: null expansion of name pattern "\1" ctags: Warning: kernel/rcu/rcutorture.c:135: null expansion of name pattern "\1" ctags: Warning: kernel/workqueue.c:323: null expansion of name pattern "\1" ctags: Warning: net/ipv4/syncookies.c:53: null expansion of name pattern "\1" ctags: Warning: net/ipv6/syncookies.c:44: null expansion of name pattern "\1" ctags: Warning: net/rds/page.c:45: null expansion of name pattern "\1" Which are all the result of the DEFINE_PER_CPU pattern: scripts/tags.sh:200: '/\<DEFINE_PER_CPU([^,]*, *\([[:alnum:]_]*\)/\1/v/' scripts/tags.sh:201: '/\<DEFINE_PER_CPU_SHARED_ALIGNED([^,]*, *\([[:alnum:]_]*\)/\1/v/' The below cures them. All except the workqueue one are within reasonable distance of the 80 char limit. TJ do you have any preference on how to fix the wq one, or shall we just not care its too long? Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Tejun Heo <tj@kernel.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05xen/events: Clear cpu_evtchn_mask before resumingBoris Ostrovsky
When a guest is resumed, the hypervisor may change event channel assignments. If this happens and the guest uses 2-level events it is possible for the interrupt to be claimed by wrong VCPU since cpu_evtchn_mask bits may be stale. This can happen even though evtchn_2l_bind_to_cpu() attempts to clear old bits: irq_info that is passed in is not necessarily the original one (from pre-migration times) but instead is freshly allocated during resume and so any information about which CPU the channel was bound to is lost. Thus we should clear the mask during resume. We also need to make sure that bits for xenstore and console channels are set when these two subsystems are resumed. While rebind_evtchn_irq() (which is invoked for both of them on a resume) calls irq_set_affinity(), the latter will in fact postpone setting affinity until handling the interrupt. But because cpu_evtchn_mask will have bits for these two cleared we won't be able to take the interrupt. With that in mind, we need to bind those two channels explicitly in rebind_evtchn_irq(). We will keep irq_set_affinity() so that we have a pass through generic irq affinity code later, in case something needs to be updated there as well. (Also replace cpumask_of(0) with cpumask_of(info->cpu) in rebind_evtchn_irq(): it should be set to zero in preceding xen_irq_info_evtchn_setup().) Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reported-by: Annie Li <annie.li@oracle.com> Cc: <stable@vger.kernel.org> # 3.14+ Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2014-03-04xen: Use the proper irq functionsThomas Gleixner
generic_handler_irq() already tests for !desc so use this instead of generic_handle_irq_desc(). Use irq_get_irq_data() instead of desc->irq_data. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Xen <xen-devel@lists.xenproject.org> Link: http://lkml.kernel.org/r/20140223212738.222412125@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-01-06xen/events: Add the hypervisor interface for the FIFO-based event channelsDavid Vrabel
Add the hypercall sub-ops and the structures for the shared data used in the FIFO-based event channel ABI. The design document for this new ABI is available here: http://xenbits.xen.org/people/dvrabel/event-channels-H.pdf In summary, events are reported using a per-domain shared event array of event words. Each event word has PENDING, LINKED and MASKED bits and a LINK field for pointing to the next event in the event queue. There are 16 event queues (with different priorities) per-VCPU. Key advantages of this new ABI include: - Support for over 100,000 events (2^17). - 16 different event priorities. - Improved fairness in event latency through the use of FIFOs. The ABI is available in Xen 4.4 and later. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2014-01-06xen/events: Refactor evtchn_to_irq array to be dynamically allocatedDavid Vrabel
Refactor static array evtchn_to_irq array to be dynamically allocated by implementing get and set functions for accesses to the array. Two new port ops are added: max_channels (maximum supported number of event channels) and nr_channels (number of currently usable event channels). For the 2-level ABI, these numbers are both the same as the shared data structure is a fixed size. For the FIFO ABI, these will be different as the event array is expanded dynamically. This allows more than 65000 event channels so an unsigned short is no longer sufficient for an event channel port number and unsigned int is used instead. Signed-off-by: Malcolm Crossley <malcolm.crossley@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2014-01-06xen/events: add struct evtchn_ops for the low-level port operationsDavid Vrabel
evtchn_ops contains the low-level operations that access the shared data structures. This allows alternate ABIs to be supported. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2014-01-06xen/events: move 2-level specific code into its own fileDavid Vrabel
In preparation for alternative event channel ABIs, move all the functions accessing the shared data structures into their own file. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>