[PATCH v4 00/10] arm64: Add support for FEAT_E2H0, or lack thereof

[Oliver Upton]

On Mon, 22 Jan 2024 18:13:34 +0000, Marc Zyngier wrote:
> Since ARMv8.1, the architecture has grown the VHE feature, which makes
> EL2 a superset of EL1. With ARMv9.5 (and retroactively allowed from
> ARMv8.1), the architecture allows implementations to have VHE as the
> *only* implemented behaviour, meaning that HCR_EL2.E2H can be
> implemented as RES1. As a follow-up, HCR_EL2.NV1 can also be
> implemented as RES0, making the VHE-ness of the architecture
> recursive.
> 
> [...]

Thanks folks for having taken a look at the series. I've pushed it out
to kvmarm/next.

Catalin, as requested here is the shared branch:

  https://git.kernel.org/pub/scm/linux/kernel/git/oupton/linux.git/log/?h=kvm-arm64/feat_e2h0

[01/10] arm64: Add macro to compose a sysreg field value
        https://git.kernel.org/kvmarm/kvmarm/c/53eaeb7fbe27
[02/10] arm64: cpufeatures: Correctly handle signed values
        https://git.kernel.org/kvmarm/kvmarm/c/d9a065914dcc
[03/10] arm64: cpufeature: Correctly display signed override values
        https://git.kernel.org/kvmarm/kvmarm/c/d42bf63fd4db
[04/10] arm64: sysreg: Add layout for ID_AA64MMFR4_EL1
        https://git.kernel.org/kvmarm/kvmarm/c/cfc680bb04c5
[05/10] arm64: cpufeature: Add ID_AA64MMFR4_EL1 handling
        https://git.kernel.org/kvmarm/kvmarm/c/805bb61f8279
[06/10] arm64: cpufeature: Detect HCR_EL2.NV1 being RES0
        https://git.kernel.org/kvmarm/kvmarm/c/da9af5071b25
[07/10] arm64: Treat HCR_EL2.E2H as RES1 when ID_AA64MMFR4_EL1.E2H0 is negative
        https://git.kernel.org/kvmarm/kvmarm/c/3944382fa6f2
[08/10] KVM: arm64: Expose ID_AA64MMFR4_EL1 to guests
        https://git.kernel.org/kvmarm/kvmarm/c/c21df6e43f0e
[09/10] KVM: arm64: Force guest's HCR_EL2.E2H RES1 when NV1 is not implemented
        https://git.kernel.org/kvmarm/kvmarm/c/94f29ab2d801
[10/10] KVM: arm64: Handle Apple M2 as not having HCR_EL2.NV1 implemented
        https://git.kernel.org/kvmarm/kvmarm/c/aade38faca63

--
Best,
Oliver