Re: [PATCH v3 3/9] RISC-V: KVM: Allow some SBI extensions to be disabled by default

[Andrew Jones]

On Fri, Oct 20, 2023 at 12:51:34PM +0530, Anup Patel wrote:
> Currently, all SBI extensions are enabled by default which is
> problematic for SBI extensions (such as DBCN) which are forwarded
> to the KVM user-space because we might have an older KVM user-space
> which is not aware/ready to handle newer SBI extensions. Ideally,
> the SBI extensions forwarded to the KVM user-space must be
> disabled by default.
> 
> To address above, we allow certain SBI extensions to be disabled
> by default so that KVM user-space must explicitly enable such
> SBI extensions to receive forwarded calls from Guest VCPU.
> 
> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> ---
>  arch/riscv/include/asm/kvm_vcpu_sbi.h |  4 ++
>  arch/riscv/kvm/vcpu.c                 |  6 +++
>  arch/riscv/kvm/vcpu_sbi.c             | 57 +++++++++++++--------------
>  3 files changed, 38 insertions(+), 29 deletions(-)
>

Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>