Re: [PATCH 4/6] RISC-V: KVM: Move copy_sbi_ext_reg_indices() to SBI implementation

[Andrew Jones <ajones@ventanamicro.com>]

On Thu, Aug 14, 2025 at 09:25:46PM +0530, Anup Patel wrote:
> The ONE_REG handling of SBI extension enable/disable registers and
> SBI extension state registers is already under SBI implementation.
> On similar lines, let's move copy_sbi_ext_reg_indices() under SBI
> implementation.
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/include/asm/kvm_vcpu_sbi.h |  2 +-
>  arch/riscv/kvm/vcpu_onereg.c          | 29 ++-------------------------
>  arch/riscv/kvm/vcpu_sbi.c             | 27 ++++++++++++++++++++++++-
>  3 files changed, 29 insertions(+), 29 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
> index 144c3f6d5eb9..212c31629bc8 100644
> --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
> +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
> @@ -78,6 +78,7 @@ void kvm_riscv_vcpu_sbi_request_reset(struct kvm_vcpu *vcpu,
>  				      unsigned long pc, unsigned long a1);
>  void kvm_riscv_vcpu_sbi_load_reset_state(struct kvm_vcpu *vcpu);
>  int kvm_riscv_vcpu_sbi_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
> +int kvm_riscv_vcpu_reg_indices_sbi_ext(struct kvm_vcpu *vcpu, u64 __user *uindices);
>  int kvm_riscv_vcpu_set_reg_sbi_ext(struct kvm_vcpu *vcpu,
>  				   const struct kvm_one_reg *reg);
>  int kvm_riscv_vcpu_get_reg_sbi_ext(struct kvm_vcpu *vcpu,
> @@ -87,7 +88,6 @@ int kvm_riscv_vcpu_set_reg_sbi(struct kvm_vcpu *vcpu, const struct kvm_one_reg *
>  int kvm_riscv_vcpu_get_reg_sbi(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
>  const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(
>  				struct kvm_vcpu *vcpu, unsigned long extid);
> -bool riscv_vcpu_supports_sbi_ext(struct kvm_vcpu *vcpu, int idx);
>  int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run);
>  void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu);
>  void kvm_riscv_vcpu_sbi_deinit(struct kvm_vcpu *vcpu);
> diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c
> index 5843b0519224..0894ab517525 100644
> --- a/arch/riscv/kvm/vcpu_onereg.c
> +++ b/arch/riscv/kvm/vcpu_onereg.c
> @@ -1060,34 +1060,9 @@ static inline unsigned long num_isa_ext_regs(const struct kvm_vcpu *vcpu)
>  	return copy_isa_ext_reg_indices(vcpu, NULL);
>  }
>  
> -static int copy_sbi_ext_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
> -{
> -	unsigned int n = 0;
> -
> -	for (int i = 0; i < KVM_RISCV_SBI_EXT_MAX; i++) {
> -		u64 size = IS_ENABLED(CONFIG_32BIT) ?
> -			   KVM_REG_SIZE_U32 : KVM_REG_SIZE_U64;
> -		u64 reg = KVM_REG_RISCV | size | KVM_REG_RISCV_SBI_EXT |
> -			  KVM_REG_RISCV_SBI_SINGLE | i;
> -
> -		if (!riscv_vcpu_supports_sbi_ext(vcpu, i))
> -			continue;
> -
> -		if (uindices) {
> -			if (put_user(reg, uindices))
> -				return -EFAULT;
> -			uindices++;
> -		}
> -
> -		n++;
> -	}
> -
> -	return n;
> -}
> -
>  static unsigned long num_sbi_ext_regs(struct kvm_vcpu *vcpu)
>  {
> -	return copy_sbi_ext_reg_indices(vcpu, NULL);
> +	return kvm_riscv_vcpu_reg_indices_sbi_ext(vcpu, NULL);
>  }
>  
>  static inline unsigned long num_sbi_regs(struct kvm_vcpu *vcpu)
> @@ -1215,7 +1190,7 @@ int kvm_riscv_vcpu_copy_reg_indices(struct kvm_vcpu *vcpu,
>  		return ret;
>  	uindices += ret;
>  
> -	ret = copy_sbi_ext_reg_indices(vcpu, uindices);
> +	ret = kvm_riscv_vcpu_reg_indices_sbi_ext(vcpu, uindices);
>  	if (ret < 0)
>  		return ret;
>  	uindices += ret;
> diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
> index 8b3c393e0c83..19e0e3d7b598 100644
> --- a/arch/riscv/kvm/vcpu_sbi.c
> +++ b/arch/riscv/kvm/vcpu_sbi.c
> @@ -110,7 +110,7 @@ riscv_vcpu_get_sbi_ext(struct kvm_vcpu *vcpu, unsigned long idx)
>  	return sext;
>  }
>  
> -bool riscv_vcpu_supports_sbi_ext(struct kvm_vcpu *vcpu, int idx)
> +static bool riscv_vcpu_supports_sbi_ext(struct kvm_vcpu *vcpu, int idx)
>  {
>  	struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
>  	const struct kvm_riscv_sbi_extension_entry *sext;
> @@ -288,6 +288,31 @@ static int riscv_vcpu_get_sbi_ext_multi(struct kvm_vcpu *vcpu,
>  	return 0;
>  }
>  
> +int kvm_riscv_vcpu_reg_indices_sbi_ext(struct kvm_vcpu *vcpu, u64 __user *uindices)
> +{
> +	unsigned int n = 0;
> +
> +	for (int i = 0; i < KVM_RISCV_SBI_EXT_MAX; i++) {
> +		u64 size = IS_ENABLED(CONFIG_32BIT) ?
> +			   KVM_REG_SIZE_U32 : KVM_REG_SIZE_U64;
> +		u64 reg = KVM_REG_RISCV | size | KVM_REG_RISCV_SBI_EXT |
> +			  KVM_REG_RISCV_SBI_SINGLE | i;
> +
> +		if (!riscv_vcpu_supports_sbi_ext(vcpu, i))
> +			continue;
> +
> +		if (uindices) {
> +			if (put_user(reg, uindices))
> +				return -EFAULT;
> +			uindices++;
> +		}
> +
> +		n++;
> +	}
> +
> +	return n;
> +}
> +
>  int kvm_riscv_vcpu_set_reg_sbi_ext(struct kvm_vcpu *vcpu,
>  				   const struct kvm_one_reg *reg)
>  {
> -- 
> 2.43.0
>

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