Page MenuHomeFreeBSD

vmm: increase vlapic version
ClosedPublic

Authored by corvink on Oct 12 2022, 12:25 PM.
Tags
Referenced Files
F132326271: D36945.diff
Wed, Oct 15, 10:26 PM
Unknown Object (File)
Mon, Oct 13, 3:25 AM
Unknown Object (File)
Mon, Oct 13, 3:25 AM
Unknown Object (File)
Mon, Oct 13, 3:25 AM
Unknown Object (File)
Mon, Oct 13, 2:15 AM
Unknown Object (File)
Sun, Oct 12, 3:30 PM
Unknown Object (File)
Sat, Oct 4, 1:50 PM
Unknown Object (File)
Sat, Sep 20, 10:12 PM
Subscribers

Details

Summary

Mac os panics on apic versions lower than 0x14.

See https://opensource.apple.com/source/xnu/xnu-7195.81.3/osfmk/i386/lapic_native.c.auto.html

Additionally, an upcoming commit will validate the icr values written by
the guest. Older intel processors allow some different combinations than
the newer ones. AMD documents that only the newer combinations are
allowed. So, bumping the version allows us to avoid a differentiation
between AMD and Intel.

Intel documents that newer processors than the P6 are using the new
combinations. Sadly, Intel does not document which apic version belongs
to those processors. Linux identifies newer apics by a version larger or
equal to 0x14. Intel and AMD allow apic version between 0x10 and 0x15.
So, using 0x14 seems to be fine.

See https://github.com/torvalds/linux/blob/3eba620e7bd772a0c7dc91966cb107872b54a910/arch/x86/kernel/apic/apic.c#L238

Diff Detail

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