Re: [PATCH v4 12/15] KVM: riscv: selftests: Add SBI PMU extension definitions

[Andrew Jones]

On Wed, Feb 28, 2024 at 05:01:27PM -0800, Atish Patra wrote:
> The SBI PMU extension definition is required for upcoming SBI PMU
> selftests.
> 
> Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
> ---
>  .../selftests/kvm/include/riscv/processor.h   | 67 +++++++++++++++++++
>  1 file changed, 67 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
> index f75c381fa35a..a49a39c8e8d4 100644
> --- a/tools/testing/selftests/kvm/include/riscv/processor.h
> +++ b/tools/testing/selftests/kvm/include/riscv/processor.h

We should probably create a new header (include/riscv/sbi.h) since
otherwise processor.h is very quickly going to look like an SBI
header with a few non-sbi things in it. Can we add a patch prior to
this one that moves the SBI stuff we currently have in processor.h
out to an sbi.h? Or, we could start synchronizing a copy of
arch/riscv/include/asm/sbi.h in tools/arch/riscv/include/asm like
we've done for csr.h

> @@ -169,17 +169,84 @@ void vm_install_exception_handler(struct kvm_vm *vm, int vector, exception_handl
>  enum sbi_ext_id {
>  	SBI_EXT_BASE = 0x10,
>  	SBI_EXT_STA = 0x535441,
> +	SBI_EXT_PMU = 0x504D55,
>  };
>  
>  enum sbi_ext_base_fid {
>  	SBI_EXT_BASE_PROBE_EXT = 3,
>  };
>  
> +enum sbi_ext_pmu_fid {
> +	SBI_EXT_PMU_NUM_COUNTERS = 0,
> +	SBI_EXT_PMU_COUNTER_GET_INFO,
> +	SBI_EXT_PMU_COUNTER_CFG_MATCH,
> +	SBI_EXT_PMU_COUNTER_START,
> +	SBI_EXT_PMU_COUNTER_STOP,
> +	SBI_EXT_PMU_COUNTER_FW_READ,
> +	SBI_EXT_PMU_COUNTER_FW_READ_HI,
> +	SBI_EXT_PMU_SNAPSHOT_SET_SHMEM,
> +};
> +
> +union sbi_pmu_ctr_info {
> +	unsigned long value;
> +	struct {
> +		unsigned long csr:12;
> +		unsigned long width:6;
> +#if __riscv_xlen == 32
> +		unsigned long reserved:13;
> +#else
> +		unsigned long reserved:45;
> +#endif
> +		unsigned long type:1;
> +	};
> +};
> +
>  struct sbiret {
>  	long error;
>  	long value;
>  };
>  
> +/** General pmu event codes specified in SBI PMU extension */
> +enum sbi_pmu_hw_generic_events_t {
> +	SBI_PMU_HW_NO_EVENT			= 0,
> +	SBI_PMU_HW_CPU_CYCLES			= 1,
> +	SBI_PMU_HW_INSTRUCTIONS			= 2,
> +	SBI_PMU_HW_CACHE_REFERENCES		= 3,
> +	SBI_PMU_HW_CACHE_MISSES			= 4,
> +	SBI_PMU_HW_BRANCH_INSTRUCTIONS		= 5,
> +	SBI_PMU_HW_BRANCH_MISSES		= 6,
> +	SBI_PMU_HW_BUS_CYCLES			= 7,
> +	SBI_PMU_HW_STALLED_CYCLES_FRONTEND	= 8,
> +	SBI_PMU_HW_STALLED_CYCLES_BACKEND	= 9,
> +	SBI_PMU_HW_REF_CPU_CYCLES		= 10,
> +
> +	SBI_PMU_HW_GENERAL_MAX,
> +};
> +
> +/* SBI PMU counter types */
> +enum sbi_pmu_ctr_type {
> +	SBI_PMU_CTR_TYPE_HW = 0x0,
> +	SBI_PMU_CTR_TYPE_FW,
> +};
> +
> +/* Flags defined for config matching function */
> +#define SBI_PMU_CFG_FLAG_SKIP_MATCH	(1 << 0)
> +#define SBI_PMU_CFG_FLAG_CLEAR_VALUE	(1 << 1)
> +#define SBI_PMU_CFG_FLAG_AUTO_START	(1 << 2)
> +#define SBI_PMU_CFG_FLAG_SET_VUINH	(1 << 3)
> +#define SBI_PMU_CFG_FLAG_SET_VSINH	(1 << 4)
> +#define SBI_PMU_CFG_FLAG_SET_UINH	(1 << 5)
> +#define SBI_PMU_CFG_FLAG_SET_SINH	(1 << 6)
> +#define SBI_PMU_CFG_FLAG_SET_MINH	(1 << 7)
> +
> +/* Flags defined for counter start function */
> +#define SBI_PMU_START_FLAG_SET_INIT_VALUE (1 << 0)
> +#define SBI_PMU_START_FLAG_INIT_FROM_SNAPSHOT BIT(1)
> +
> +/* Flags defined for counter stop function */
> +#define SBI_PMU_STOP_FLAG_RESET (1 << 0)
> +#define SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT BIT(1)

When changing shifts to BIT()'s, don't forget these (easy not to forget
if we go with the synch sbi.h to tools approach)

> +
>  struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>  			unsigned long arg1, unsigned long arg2,
>  			unsigned long arg3, unsigned long arg4,
> -- 
> 2.34.1
>

Thanks,
drew