[PATCH 3/5] RISC-V: KVM: Allow bfloat16 extension for Guest/VM

[Andrew Jones]

On Tue, Jun 17, 2025 at 09:10:35PM +0800, zhouquan at iscas.ac.cn wrote:
> From: Quan Zhou <zhouquan at iscas.ac.cn>
> 
> Extend the KVM ISA extension ONE_REG interface to allow KVM user space
> to detect and enable Zfbmin/Zvfbfmin/Zvfbfwma extension for Guest/VM.
> 
> Signed-off-by: Quan Zhou <zhouquan at iscas.ac.cn>
> ---
>  arch/riscv/include/uapi/asm/kvm.h | 3 +++
>  arch/riscv/kvm/vcpu_onereg.c      | 6 ++++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
> index 56959d277e86..79a5ac86597c 100644
> --- a/arch/riscv/include/uapi/asm/kvm.h
> +++ b/arch/riscv/include/uapi/asm/kvm.h
> @@ -186,6 +186,9 @@ enum KVM_RISCV_ISA_EXT_ID {
>  	KVM_RISCV_ISA_EXT_ZAAMO,
>  	KVM_RISCV_ISA_EXT_ZALRSC,
>  	KVM_RISCV_ISA_EXT_ZICBOP,
> +	KVM_RISCV_ISA_EXT_ZFBFMIN,
> +	KVM_RISCV_ISA_EXT_ZVFBFMIN,
> +	KVM_RISCV_ISA_EXT_ZVFBFWMA,
>  	KVM_RISCV_ISA_EXT_MAX,
>  };
>  
> diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c
> index d444ec9e9e8e..2ba3f2c942ee 100644
> --- a/arch/riscv/kvm/vcpu_onereg.c
> +++ b/arch/riscv/kvm/vcpu_onereg.c
> @@ -65,6 +65,7 @@ static const unsigned long kvm_isa_ext_arr[] = {
>  	KVM_ISA_EXT_ARR(ZCF),
>  	KVM_ISA_EXT_ARR(ZCMOP),
>  	KVM_ISA_EXT_ARR(ZFA),
> +	KVM_ISA_EXT_ARR(ZFBFMIN),
>  	KVM_ISA_EXT_ARR(ZFH),
>  	KVM_ISA_EXT_ARR(ZFHMIN),
>  	KVM_ISA_EXT_ARR(ZICBOM),
> @@ -89,6 +90,8 @@ static const unsigned long kvm_isa_ext_arr[] = {
>  	KVM_ISA_EXT_ARR(ZTSO),
>  	KVM_ISA_EXT_ARR(ZVBB),
>  	KVM_ISA_EXT_ARR(ZVBC),
> +	KVM_ISA_EXT_ARR(ZVFBFMIN),
> +	KVM_ISA_EXT_ARR(ZVFBFWMA),
>  	KVM_ISA_EXT_ARR(ZVFH),
>  	KVM_ISA_EXT_ARR(ZVFHMIN),
>  	KVM_ISA_EXT_ARR(ZVKB),
> @@ -170,6 +173,7 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
>  	case KVM_RISCV_ISA_EXT_ZCF:
>  	case KVM_RISCV_ISA_EXT_ZCMOP:
>  	case KVM_RISCV_ISA_EXT_ZFA:
> +	case KVM_RISCV_ISA_EXT_ZFBFMIN:
>  	case KVM_RISCV_ISA_EXT_ZFH:
>  	case KVM_RISCV_ISA_EXT_ZFHMIN:
>  	case KVM_RISCV_ISA_EXT_ZICBOP:
> @@ -192,6 +196,8 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
>  	case KVM_RISCV_ISA_EXT_ZTSO:
>  	case KVM_RISCV_ISA_EXT_ZVBB:
>  	case KVM_RISCV_ISA_EXT_ZVBC:
> +	case KVM_RISCV_ISA_EXT_ZVFBFMIN:
> +	case KVM_RISCV_ISA_EXT_ZVFBFWMA:
>  	case KVM_RISCV_ISA_EXT_ZVFH:
>  	case KVM_RISCV_ISA_EXT_ZVFHMIN:
>  	case KVM_RISCV_ISA_EXT_ZVKB:
> -- 
> 2.34.1
>

Reviewed-by: Andrew Jones <ajones at ventanamicro.com>