On Fri, Mar 15, 2024 at 04:32:10PM -0700, Oliver Upton wrote:
> On Fri, Mar 15, 2024 at 03:28:29PM -0700, Linus Torvalds wrote:
> > The immediate cause of the failure is commit b80b701d5a67 ("KVM:
> > arm64: Snapshot all non-zero RES0/RES1 sysreg fields for later
> > checking") but I hope it worked at *some* point. I can't see how.
>
> Looks like commit fdd867fe9b32 ("arm64/sysreg: Add register fields for
> ID_AA64DFR1_EL1") changed the register definition that tripped the
> BUILD_BUG_ON().
>
> But it'd be *wildly* unfair to blame that, the KVM assertions are added
> out of fear of new register definitions breaking our sysreg emulation.
>
> > I would guess / assume that commit cfc680bb04c5 ("arm64: sysreg: Add
> > layout for ID_AA64MMFR4_EL1") is also involved, but having recoiled in
> > horror from the awk script, I really can't even begin to guess at what
> > is going on.
> >
> > Bringing in other people who hopefully can sort this out.
>
> At this point I'm heavily biased towards just dropping the KVM checks
> for now than attempt a fix-forward. We can work things out better with
> arm64 folks next release.
>
> So unless anyone screams, I say we revert:
>
> 99101dda29e3 ("KVM: arm64: Make build-time check of RES0/RES1 bits optional")
> 891766581dea ("KVM: arm64: Add debugfs file for guest's ID registers")
Duh, that second one should actually be:
b80b701d5a67 ("KVM: arm64: Snapshot all non-zero RES0/RES1 sysreg fields for later checking")
--
Thanks,
Oliver
