Re: [PATCH v2 4/5] KVM: selftests: Add an interface to read the data of named vcpu stat

[Manali Shukla <manali.shukla@amd.com>]

On 5/2/2024 6:44 PM, Andrew Jones wrote:
> On Wed, May 01, 2024 at 02:54:32PM GMT, Manali Shukla wrote:
>> From: Manali Shukla <Manali.Shukla@amd.com>
>>
>> The interface is used to read the data values of a specified vcpu stat
>> from the currenly available binary stats interface.
>>
>> Signed-off-by: Manali Shukla <Manali.Shukla@amd.com>
>> ---
>>  .../testing/selftests/kvm/include/kvm_util.h  | 66 +++++++++++++++++++
>>  tools/testing/selftests/kvm/lib/kvm_util.c    | 32 +++++++++
>>  2 files changed, 98 insertions(+)
>>
>> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
>> index 63c2aaae51f3..7dad3275a4d3 100644
>> --- a/tools/testing/selftests/kvm/include/kvm_util.h
>> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
>> @@ -518,6 +518,72 @@ static inline uint64_t vm_get_stat(struct kvm_vm *vm, const char *stat_name)
>>  	return data;
>>  }
>>  
>> +/*
>> + * Ensure that the sequence of the enum vcpu_stat_types matches the order of
>> + * kvm_vcpu_stats_desc[].  Otherwise, vcpu_get_stat() may return incorrect data
>> + * because __vcpu_get_stat() uses the enum type as an index to get the
>> + * descriptor for a given stat and then uses read_stat_data() to get the stats
>> + * from the descriptor.
>> + */
>> +enum vcpu_stat_types {
>> +	HALT_SUCCESSFUL_POLL,
>> +	HALT_ATTEMPTED_POLL,
>> +	HALT_POLL_INVALID,
>> +	HALT_WAKEUP,
>> +	HALT_POLL_SUCCESS_NS,
>> +	HALT_POLL_FAIL_NS,
>> +	HALT_WAIT_NS,
>> +	HALT_POLL_SUCCESS_HIST,
>> +	HALT_POLL_FAIL_HIST,
>> +	HALT_WAIT_HIST,
>> +	BLOCKING,
> 
> Everything below here is x86 specific, but this is an arch-neutral file.
> Please structure this in a way that each architecture can share the
> generic types and also provide its own.
> 
> Thanks,
> drew

Thank you for reviewing my patches.
Sure. I will take care of it in the next version.

-Manali

> 
>> +	PF_TAKEN,
>> +	PF_FIXED,
>> +	PF_EMULATE,
>> +	PF_SPURIOUS,
>> +	PF_FAST,
>> +	PF_MMIO_SPTE_CREATED,
>> +	PF_GUEST,
>> +	TLB_FLUSH,
>> +	INVLPG,
>> +	EXITS,
>> +	IO_EXITS,
>> +	MMIO_EXITS,
>> +	SIGNAL_EXITS,
>> +	IRQ_WINDOW_EXITS,
>> +	NMI_WINDOW_EXITS,
>> +	LD_FLUSH,
>> +	HALT_EXITS,
>> +	REQUEST_IRQ_EXITS,
>> +	IRQ_EXITS,
>> +	HOST_STATE_RELOAD,
>> +	FPU_RELOAD,
>> +	INSN_EMULATION,
>> +	INSN_EMULATION_FAIL,
>> +	HYPERCALLS,
>> +	IRQ_INJECTIONS,
>> +	NMI_INJECTIONS,
>> +	REQ_EVENT,
>> +	NESTED_RUN,
>> +	DIRECTED_YIELD_ATTEMPTED,
>> +	DIRECTED_YIELD_SUCCESSFUL,
>> +	PREEMPTION_REPORTED,
>> +	PREEMPTION_OTHER,
>> +	GUEST_MODE,
>> +	NOTIFY_WINDOW_EXITS,
>> +};
>> +
>> +void __vcpu_get_stat(struct kvm_vcpu *vcpu, enum vcpu_stat_types type, uint64_t *data,
>> +		   size_t max_elements);
>> +
>> +static inline uint64_t vcpu_get_stat(struct kvm_vcpu *vcpu, enum vcpu_stat_types type)
>> +{
>> +	uint64_t data;
>> +
>> +	__vcpu_get_stat(vcpu, type, &data, 1);
>> +	return data;
>> +}
>> +
>>  void vm_create_irqchip(struct kvm_vm *vm);
>>  
>>  static inline int __vm_create_guest_memfd(struct kvm_vm *vm, uint64_t size,
>> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
>> index 6b2158655baa..3de292ca9280 100644
>> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
>> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
>> @@ -2256,6 +2256,38 @@ void read_stat_data(int stats_fd, struct kvm_stats_header *header,
>>  		    desc->name, size, ret);
>>  }
>>  
>> +/*
>> + * Read the data of the named vcpu stat
>> + *
>> + * Input Args:
>> + *   vcpu - the vcpu for which the stat should be read
>> + *   stat_name - the name of the stat to read
>> + *   max_elements - the maximum number of 8-byte values to read into data
>> + *
>> + * Output Args:
>> + *   data - the buffer into which stat data should be read
>> + *
>> + * Read the data values of a specified stat from the binary stats interface.
>> + */
>> +void __vcpu_get_stat(struct kvm_vcpu *vcpu, enum vcpu_stat_types type, uint64_t *data,
>> +		   size_t max_elements)
>> +{
>> +	int vcpu_stats_fd;
>> +	struct kvm_stats_header header;
>> +	struct kvm_stats_desc *desc, *t_desc;
>> +	size_t size_desc;
>> +
>> +	vcpu_stats_fd = vcpu_get_stats_fd(vcpu);
>> +	read_stats_header(vcpu_stats_fd, &header);
>> +
>> +	desc = read_stats_descriptors(vcpu_stats_fd, &header);
>> +	size_desc = get_stats_descriptor_size(&header);
>> +
>> +	t_desc = (void *)desc + (type * size_desc);
>> +	read_stat_data(vcpu_stats_fd, &header, t_desc,
>> +			data, max_elements);
>> +}
>> +
>>  /*
>>   * Read the data of the named stat
>>   *
>> -- 
>> 2.34.1
>>