Messages in this thread | | | Date | Mon, 13 Sep 2021 09:35:12 +0200 | From | Andrew Jones <> | Subject | Re: [PATCH v4 09/18] KVM: arm64: selftests: Add guest support to get the vcpuid |
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On Sun, Sep 12, 2021 at 12:05:22AM -0700, Reiji Watanabe wrote: > Hi Raghu and all, > > On Wed, Sep 8, 2021 at 6:38 PM Raghavendra Rao Ananta > <rananta@google.com> wrote: > > > > At times, such as when in the interrupt handler, the guest wants > > to get the vcpuid that it's running on. As a result, introduce > > get_vcpuid() that returns the vcpuid of the calling vcpu. At its > > backend, the VMM prepares a map of vcpuid and mpidr during VM > > initialization and exports the map to the guest for it to read. > > How about using TPIDR_EL1 to hold the vcpuid ? > i.e. have aarch64_vcpu_setup() set the register to vcpuid and > guest_get_vcpuid() simply return a value of the register. > This would be a simpler solution to implement.
That is a great suggestion. It's arch-specific, but maybe the other architectures can mimic it with their own capabilities. And, in the unlikely event a unit test wants that register for itself, then it can build its own mpidr-vcpuid map if necessary. Ship it :-)
Thanks, drew
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