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path: root/drivers/xen/events/events_2l.c
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* xen/events: Clear cpu_evtchn_mask before resumingBoris Ostrovsky2015-05-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* xen: Use the proper irq functionsThomas Gleixner2014-03-04
| | | | | | | | | | | | | | | 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>
* xen/events: Add the hypervisor interface for the FIFO-based event channelsDavid Vrabel2014-01-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* xen/events: Refactor evtchn_to_irq array to be dynamically allocatedDavid Vrabel2014-01-06
| | | | | | | | | | | | | | | | | | | | 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>
* xen/events: add struct evtchn_ops for the low-level port operationsDavid Vrabel2014-01-06
| | | | | | | | | 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>
* xen/events: move 2-level specific code into its own fileDavid Vrabel2014-01-06
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>