Messages in this thread | | | Subject | Re: [RFC PATCH 07/16] x86/xen: make vcpu_info part of xenhost_t | From | Ankur Arora <> | Date | Sun, 16 Jun 2019 23:28:39 -0700 |
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On 2019-06-14 4:53 a.m., Juergen Gross wrote: > On 09.05.19 19:25, Ankur Arora wrote: >> Abstract out xen_vcpu_id probing via (*probe_vcpu_id)(). Once that is >> availab,e the vcpu_info registration happens via the VCPUOP hypercall. >> >> Note that for the nested case, there are two vcpu_ids, and two vcpu_info >> areas, one each for the default xenhost and the remote xenhost. >> The vcpu_info is used via pv_irq_ops, and evtchn signaling. >> >> The other VCPUOP hypercalls are used for management (and scheduling) >> which is expected to be done purely in the default hypervisor. >> However, scheduling of L1-guest does imply L0-Xen-vcpu_info switching, >> which might mean that the remote hypervisor needs some visibility >> into related events/hypercalls in the default hypervisor. > > Another candidate for dropping due to layering violation, I guess. Yeah, a more narrowly tailored interface, where perhaps the L1-Xen maps events for L0-Xen makes sense. Also, just realized that given that L0-Xen has no control over scheduling of L1-Xen's guests (some of which it might want to send events to), it makes sense for L1-Xen to have some state for guest evtchns which pertain to L0-Xen.
Ankur
> > > Juergen
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