Re: [PATCH v3 8/9] KVM: riscv: selftests: Change vcpu_has_ext to a common function

[Andrew Jones]

On Thu, Sep 14, 2023 at 09:37:02AM +0800, Haibo Xu wrote:
> Move vcpu_has_ext to the processor.c and rename it to __vcpu_has_ext
> so that other test cases can use it for vCPU extension check.
> 
> Signed-off-by: Haibo Xu <haibo1.xu@xxxxxxxxx>
> ---
>  .../selftests/kvm/include/riscv/processor.h      |  2 ++
>  .../testing/selftests/kvm/lib/riscv/processor.c  |  9 +++++++++
>  tools/testing/selftests/kvm/riscv/get-reg-list.c | 16 +---------------
>  3 files changed, 12 insertions(+), 15 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
> index 2c975d9cead2..7d5517648ea7 100644
> --- a/tools/testing/selftests/kvm/include/riscv/processor.h
> +++ b/tools/testing/selftests/kvm/include/riscv/processor.h
> @@ -42,6 +42,8 @@ static inline uint64_t __kvm_reg_id(uint64_t type, uint64_t idx,
>  #define RISCV_ISA_EXT_REG(idx)	__kvm_reg_id(KVM_REG_RISCV_ISA_EXT, \
>  					     idx, KVM_REG_SIZE_ULONG)
>  
> +bool __vcpu_has_ext(struct kvm_vcpu *vcpu, int ext);
> +
>  struct ex_regs {
>  	unsigned long ra;
>  	unsigned long sp;
> diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c
> index 39a1e9902dec..e527ad0abc30 100644
> --- a/tools/testing/selftests/kvm/lib/riscv/processor.c
> +++ b/tools/testing/selftests/kvm/lib/riscv/processor.c
> @@ -15,6 +15,15 @@
>  
>  static vm_vaddr_t exception_handlers;
>  
> +bool __vcpu_has_ext(struct kvm_vcpu *vcpu, int ext)
> +{
> +	unsigned long value = 0;
> +
> +	__vcpu_get_reg(vcpu, RISCV_ISA_EXT_REG(ext), &value);
> +
> +	return !!value;

I'd rather not assume that value will remain zero across a system call
which fails. Let's write this as

     unsigned long value = 0;
     int ret;

     ret = __vcpu_get_reg(vcpu, RISCV_ISA_EXT_REG(ext), &value);

     return !ret && !!value;

> +}
> +
>  static uint64_t page_align(struct kvm_vm *vm, uint64_t v)
>  {
>  	return (v + vm->page_size) & ~(vm->page_size - 1);
> diff --git a/tools/testing/selftests/kvm/riscv/get-reg-list.c b/tools/testing/selftests/kvm/riscv/get-reg-list.c
> index d8ecacd03ecf..0dcff823f287 100644
> --- a/tools/testing/selftests/kvm/riscv/get-reg-list.c
> +++ b/tools/testing/selftests/kvm/riscv/get-reg-list.c
> @@ -44,20 +44,6 @@ bool check_reject_set(int err)
>  	return err == EINVAL;
>  }
>  
> -static inline bool vcpu_has_ext(struct kvm_vcpu *vcpu, int ext)
> -{
> -	int ret;
> -	unsigned long value;
> -
> -	ret = __vcpu_get_reg(vcpu, RISCV_ISA_EXT_REG(ext), &value);
> -	if (ret) {
> -		printf("Failed to get ext %d", ext);
> -		return false;
> -	}
> -
> -	return !!value;
> -}
> -
>  void finalize_vcpu(struct kvm_vcpu *vcpu, struct vcpu_reg_list *c)
>  {
>  	struct vcpu_reg_sublist *s;
> @@ -77,7 +63,7 @@ void finalize_vcpu(struct kvm_vcpu *vcpu, struct vcpu_reg_list *c)
>  		__vcpu_set_reg(vcpu, RISCV_ISA_EXT_REG(s->feature), 1);
>  
>  		/* Double check whether the desired extension was enabled */
> -		__TEST_REQUIRE(vcpu_has_ext(vcpu, s->feature),
> +		__TEST_REQUIRE(__vcpu_has_ext(vcpu, s->feature),
>  			       "%s not available, skipping tests\n", s->name);
>  	}
>  }
> -- 
> 2.34.1
>

Otherwise,

Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>

Thanks,
drew