Page MenuHomeFreeBSD

arm64/vmm: Use FEAT_ECV_POFF to support a timer
ClosedPublic

Authored by andrew on Aug 8 2025, 12:21 PM.
Tags
None
Referenced Files
Unknown Object (File)
Sat, Oct 11, 12:13 AM
Unknown Object (File)
Sat, Oct 11, 12:13 AM
Unknown Object (File)
Sat, Oct 11, 12:13 AM
Unknown Object (File)
Fri, Oct 10, 5:44 PM
Unknown Object (File)
Mon, Sep 29, 10:38 AM
Unknown Object (File)
Sat, Sep 27, 1:51 PM
Unknown Object (File)
Thu, Sep 25, 6:29 PM
Unknown Object (File)
Wed, Sep 24, 11:29 PM
Subscribers

Details

Summary

Support guest access to the physical timer when FEAT_ECV_POFF is
supported. In this case we can set an offset for the physical timer.
We can reuse the virtual timer support to also support the physical
timer, with a few more registers needing to be handled when switching
to a guest.

As it is not clear how this will affect performance when the guest
doesn't use it hide enabling it behind a sysctl.

It is expected this will be useful when Nested Virtualisation is
supported as guests are expected to use the physical timer registers.

Sponsored by: Arm Ltd

Diff Detail

Repository
rG FreeBSD src repository
Lint
Lint Not Applicable
Unit
Tests Not Applicable

Event Timeline

This revision was not accepted when it landed; it landed in state Needs Review.Tue, Sep 23, 5:10 PM
This revision was automatically updated to reflect the committed changes.