[PATCH v3 9/9] RISC-V: KVM: Upgrade the supported SBI version to 3.0

[Radim Krčmář]

2025-05-22T12:03:43-07:00, Atish Patra <atishp at rivosinc.com>:
> Upgrade the SBI version to v3.0 so that corresponding features
> can be enabled in the guest.
>
> Signed-off-by: Atish Patra <atishp at rivosinc.com>
> ---
> diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
> -#define KVM_SBI_VERSION_MAJOR 2
> +#define KVM_SBI_VERSION_MAJOR 3

I think it's time to add versioning to KVM SBI implementation.
Userspace should be able to select the desired SBI version and KVM would
tell the guest that newer features are not supported.

We could somewhat get away with the userspace_sbi patch I posted,
because userspace would at least be in control of the SBI version, but
it would still be incorrect without a KVM enforcement, because a
misbehaving guest could use features that should not be supported.