Messages in this thread | | | Date | Thu, 2 Jul 2015 17:21:41 +0100 | From | David Vrabel <> | Subject | Re: [Xen-devel] [PATCH v5 3/6] xen/PMU: Initialization code for Xen PMU |
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On 02/07/15 15:53, Boris Ostrovsky wrote: > Map shared data structure that will hold CPU registers, VPMU context, > V/PCPU IDs of the CPU interrupted by PMU interrupt. Hypervisor fills > this information in its handler and passes it to the guest for further > processing. > > Set up PMU VIRQ. > > Now that perf infrastructure will assume that PMU is available on a PV > guest we need to be careful and make sure that accesses via RDPMC > instruction don't cause fatal traps by the hypervisor. Provide a nop > RDPMC handler. > > For the same reason avoid issuing a warning on a write to APIC's LVTPC. > > Both of these will be made functional in later patches. [...] > + rc = bind_virq_to_irqhandler(VIRQ_XENPMU, cpu, > + xen_pmu_irq_handler, > + IRQF_PERCPU|IRQF_NOBALANCING, > + pmu_name, NULL);
If you bind a VIRQ as IRQF_PERCPU it can only be safely unbound on the CPU it is bound to (because the percpu handler does not take the desc->lock).
Otherwise, Reviewed-by: David Vrabel <david.vrabel@citrix.com>
David
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