Messages in this thread | | | Subject | Re: [Xen-devel] [RFC PATCH 04/16] x86/xen: hypercall support for xenhost_t | From | Ankur Arora <> | Date | Fri, 14 Jun 2019 00:20:28 -0700 |
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On 2019-06-12 2:15 p.m., Andrew Cooper wrote: > On 09/05/2019 18:25, Ankur Arora wrote: >> Allow for different hypercall implementations for different xenhost types. >> Nested xenhost, which has two underlying xenhosts, can use both >> simultaneously. >> >> The hypercall macros (HYPERVISOR_*) implicitly use the default xenhost.x >> A new macro (hypervisor_*) takes xenhost_t * as a parameter and does the >> right thing. >> >> TODO: >> - Multicalls for now assume the default xenhost >> - xen_hypercall_* symbols are only generated for the default xenhost. >> >> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> > > Again, what is the hypervisor nesting and/or guest layout here? Two hypervisors, L0 and L1, and the guest is a child of the L1 hypervisor but could have PV devices attached to both L0 and L1 hypervisors.
> > I can't think of any case where a single piece of software can > legitimately have two hypercall pages, because if it has one working > one, it is by definition a guest, and therefore not privileged enough to > use the outer one. Depending on which hypercall page is used, the hypercall would (eventually) land in the corresponding hypervisor.
Juergen elsewhere pointed out proxying hypercalls is a better approach, so I'm not really considering this any more but, given this layout, and assuming that the hypercall pages could be encoded differently would it still not work?
Ankur
> > ~Andrew > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xenproject.org > https://lists.xenproject.org/mailman/listinfo/xen-devel >
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