Re: [kvm-unit-tests PATCH v11 4/8] lib: riscv: Add functions for version checking

[Andrew Jones <andrew.jones@linux.dev>]

On Mon, Mar 17, 2025 at 05:46:49PM +0100, Clément Léger wrote:
> Version checking was done using some custom hardcoded values, backport a
> few SBI function and defines from Linux to do that cleanly.
> 
> Signed-off-by: Clément Léger <cleger@rivosinc.com>
> ---
>  lib/riscv/asm/sbi.h | 15 +++++++++++++++
>  lib/riscv/sbi.c     |  9 +++++++--
>  2 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/riscv/asm/sbi.h b/lib/riscv/asm/sbi.h
> index 2f4d91ef..ee9d6e50 100644
> --- a/lib/riscv/asm/sbi.h
> +++ b/lib/riscv/asm/sbi.h
> @@ -18,6 +18,13 @@
>  #define SBI_ERR_IO			-13
>  #define SBI_ERR_DENIED_LOCKED		-14
>  
> +/* SBI spec version fields */
> +#define SBI_SPEC_VERSION_MAJOR_SHIFT	24
> +#define SBI_SPEC_VERSION_MAJOR_MASK	0x7f
> +#define SBI_SPEC_VERSION_MINOR_MASK	0xffffff
> +#define SBI_SPEC_VERSION_MASK		((SBI_SPEC_VERSION_MAJOR_MASK << SBI_SPEC_VERSION_MAJOR_SHIFT) | \
> +					SBI_SPEC_VERSION_MINOR_MASK)
                                       ^ needs one more space
> +
>  #ifndef __ASSEMBLER__
>  #include <cpumask.h>
>  
> @@ -110,6 +117,13 @@ struct sbiret {
>  	long value;
>  };
>  
> +/* Make SBI version */

Unnecessary comment, it's the same as the function name.

> +static inline unsigned long sbi_mk_version(unsigned long major, unsigned long minor)
> +{
> +	return ((major & SBI_SPEC_VERSION_MAJOR_MASK) << SBI_SPEC_VERSION_MAJOR_SHIFT)
> +		| (minor & SBI_SPEC_VERSION_MINOR_MASK);
> +}
> +
>  struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>  			unsigned long arg1, unsigned long arg2,
>  			unsigned long arg3, unsigned long arg4,
> @@ -124,6 +138,7 @@ struct sbiret sbi_send_ipi_cpu(int cpu);
>  struct sbiret sbi_send_ipi_cpumask(const cpumask_t *mask);
>  struct sbiret sbi_send_ipi_broadcast(void);
>  struct sbiret sbi_set_timer(unsigned long stime_value);
> +struct sbiret sbi_get_spec_version(void);
>  long sbi_probe(int ext);
>  
>  #endif /* !__ASSEMBLER__ */
> diff --git a/lib/riscv/sbi.c b/lib/riscv/sbi.c
> index 02dd338c..9d4eb541 100644
> --- a/lib/riscv/sbi.c
> +++ b/lib/riscv/sbi.c
> @@ -107,12 +107,17 @@ struct sbiret sbi_set_timer(unsigned long stime_value)
>  	return sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0, 0, 0, 0, 0);
>  }
>  
> +struct sbiret sbi_get_spec_version(void)
> +{
> +	return sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_SPEC_VERSION, 0, 0, 0, 0, 0, 0);
> +}
> +
>  long sbi_probe(int ext)
>  {
>  	struct sbiret ret;
>  
> -	ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_SPEC_VERSION, 0, 0, 0, 0, 0, 0);
> -	assert(!ret.error && (ret.value & 0x7ffffffful) >= 2);
> +	ret = sbi_get_spec_version();
> +	assert(!ret.error && (ret.value & SBI_SPEC_VERSION_MASK) >= sbi_mk_version(0, 2));
>  
>  	ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_PROBE_EXT, ext, 0, 0, 0, 0, 0);
>  	assert(!ret.error);
> -- 
> 2.47.2
>

I fixed those two things up while applying.

Thanks,
drew