Re: [PATCH 2/3] KVM: selftests: Refactor help message for -s backing_src

[Andrew Jones <drjones@redhat.com>]

On Wed, Sep 15, 2021 at 09:30:33PM +0000, David Matlack wrote:
> All selftests that support the backing_src option were printing their
> own description of the flag and then calling backing_src_help() to dump
> the list of available backing sources. Consolidate the flag printing in
> backing_src_help() to align indentation, reduce duplicated strings, and
> improve consistency across tests.
> 
> Note: Passing "-s" to backing_src_help is unnecessary since every test
> uses the same flag. However I decided to keep it for code readability
> at the call sites.

I think I'd prefer not passing "-s", but I won't insist.

> 
> While here this opportunistically fixes the incorrectly interleaved
> printing -x help message and list of backing source types in
> dirty_log_perf_test.
> 
> Fixes: 609e6202ea5f ("KVM: selftests: Support multiple slots in dirty_log_perf_test")
> Signed-off-by: David Matlack <dmatlack@google.com>
> ---
>  .../selftests/kvm/access_tracking_perf_test.c   |  6 ++----
>  .../testing/selftests/kvm/demand_paging_test.c  |  5 ++---
>  .../testing/selftests/kvm/dirty_log_perf_test.c |  8 +++-----
>  tools/testing/selftests/kvm/include/test_util.h |  5 ++++-
>  .../testing/selftests/kvm/kvm_page_table_test.c |  7 ++-----
>  tools/testing/selftests/kvm/lib/test_util.c     | 17 +++++++++++++----
>  6 files changed, 26 insertions(+), 22 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/access_tracking_perf_test.c b/tools/testing/selftests/kvm/access_tracking_perf_test.c
> index 71e277c7c3f3..5d95113c7b7c 100644
> --- a/tools/testing/selftests/kvm/access_tracking_perf_test.c
> +++ b/tools/testing/selftests/kvm/access_tracking_perf_test.c
> @@ -371,9 +371,7 @@ static void help(char *name)
>  	printf(" -v: specify the number of vCPUs to run.\n");
>  	printf(" -o: Overlap guest memory accesses instead of partitioning\n"
>  	       "     them into a separate region of memory for each vCPU.\n");
> -	printf(" -s: specify the type of memory that should be used to\n"
> -	       "     back the guest data region.\n\n");
> -	backing_src_help();
> +	backing_src_help("-s");
>  	puts("");
>  	exit(0);
>  }
> @@ -381,7 +379,7 @@ static void help(char *name)
>  int main(int argc, char *argv[])
>  {
>  	struct test_params params = {
> -		.backing_src = VM_MEM_SRC_ANONYMOUS,
> +		.backing_src = DEFAULT_VM_MEM_SRC,
>  		.vcpu_memory_bytes = DEFAULT_PER_VCPU_MEM_SIZE,
>  		.vcpus = 1,
>  	};
> diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
> index 735c081e774e..96cd3e0357f6 100644
> --- a/tools/testing/selftests/kvm/demand_paging_test.c
> +++ b/tools/testing/selftests/kvm/demand_paging_test.c
> @@ -426,8 +426,7 @@ static void help(char *name)
>  	printf(" -b: specify the size of the memory region which should be\n"
>  	       "     demand paged by each vCPU. e.g. 10M or 3G.\n"
>  	       "     Default: 1G\n");
> -	printf(" -s: The type of backing memory to use. Default: anonymous\n");
> -	backing_src_help();
> +	backing_src_help("-s");
>  	printf(" -v: specify the number of vCPUs to run.\n");
>  	printf(" -o: Overlap guest memory accesses instead of partitioning\n"
>  	       "     them into a separate region of memory for each vCPU.\n");
> @@ -439,7 +438,7 @@ int main(int argc, char *argv[])
>  {
>  	int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
>  	struct test_params p = {
> -		.src_type = VM_MEM_SRC_ANONYMOUS,
> +		.src_type = DEFAULT_VM_MEM_SRC,
>  		.partition_vcpu_memory_access = true,
>  	};
>  	int opt;
> diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> index 3c30d0045d8d..5ad9f2bc7369 100644
> --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
> +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
> @@ -308,11 +308,9 @@ static void help(char *name)
>  	printf(" -v: specify the number of vCPUs to run.\n");
>  	printf(" -o: Overlap guest memory accesses instead of partitioning\n"
>  	       "     them into a separate region of memory for each vCPU.\n");
> -	printf(" -s: specify the type of memory that should be used to\n"
> -	       "     back the guest data region.\n\n");
> +	backing_src_help("-s");
>  	printf(" -x: Split the memory region into this number of memslots.\n"
> -	       "     (default: 1)");
> -	backing_src_help();
> +	       "     (default: 1)\n");
>  	puts("");
>  	exit(0);
>  }
> @@ -324,7 +322,7 @@ int main(int argc, char *argv[])
>  		.iterations = TEST_HOST_LOOP_N,
>  		.wr_fract = 1,
>  		.partition_vcpu_memory_access = true,
> -		.backing_src = VM_MEM_SRC_ANONYMOUS,
> +		.backing_src = DEFAULT_VM_MEM_SRC,
>  		.slots = 1,
>  	};
>  	int opt;
> diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h
> index d79be15dd3d2..2f09f2994733 100644
> --- a/tools/testing/selftests/kvm/include/test_util.h
> +++ b/tools/testing/selftests/kvm/include/test_util.h
> @@ -68,6 +68,7 @@ struct timespec timespec_sub(struct timespec ts1, struct timespec ts2);
>  struct timespec timespec_elapsed(struct timespec start);
>  struct timespec timespec_div(struct timespec ts, int divisor);
>  
> +

New extra blank line. Added on purpose?

>  enum vm_mem_backing_src_type {
>  	VM_MEM_SRC_ANONYMOUS,
>  	VM_MEM_SRC_ANONYMOUS_THP,
> @@ -90,6 +91,8 @@ enum vm_mem_backing_src_type {
>  	NUM_SRC_TYPES,
>  };
>  
> +#define DEFAULT_VM_MEM_SRC VM_MEM_SRC_ANONYMOUS
> +
>  struct vm_mem_backing_src_alias {
>  	const char *name;
>  	uint32_t flag;
> @@ -100,7 +103,7 @@ size_t get_trans_hugepagesz(void);
>  size_t get_def_hugetlb_pagesz(void);
>  const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i);
>  size_t get_backing_src_pagesz(uint32_t i);
> -void backing_src_help(void);
> +void backing_src_help(const char *flag);
>  enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name);
>  
>  /*
> diff --git a/tools/testing/selftests/kvm/kvm_page_table_test.c b/tools/testing/selftests/kvm/kvm_page_table_test.c
> index 0d04a7db7f24..36407cb0ec85 100644
> --- a/tools/testing/selftests/kvm/kvm_page_table_test.c
> +++ b/tools/testing/selftests/kvm/kvm_page_table_test.c
> @@ -456,10 +456,7 @@ static void help(char *name)
>  	       "     (default: 1G)\n");
>  	printf(" -v: specify the number of vCPUs to run\n"
>  	       "     (default: 1)\n");
> -	printf(" -s: specify the type of memory that should be used to\n"
> -	       "     back the guest data region.\n"
> -	       "     (default: anonymous)\n\n");
> -	backing_src_help();
> +	backing_src_help("-s");
>  	puts("");
>  }
>  
> @@ -468,7 +465,7 @@ int main(int argc, char *argv[])
>  	int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
>  	struct test_params p = {
>  		.test_mem_size = DEFAULT_TEST_MEM_SIZE,
> -		.src_type = VM_MEM_SRC_ANONYMOUS,
> +		.src_type = DEFAULT_VM_MEM_SRC,
>  	};
>  	int opt;
>  
> diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c
> index af1031fed97f..ea23a86132ed 100644
> --- a/tools/testing/selftests/kvm/lib/test_util.c
> +++ b/tools/testing/selftests/kvm/lib/test_util.c
> @@ -279,13 +279,22 @@ size_t get_backing_src_pagesz(uint32_t i)
>  	}
>  }
>  
> -void backing_src_help(void)
> +void print_available_backing_src_types(const char *prefix)

This can probably be static.

>  {
>  	int i;
>  
> -	printf("Available backing src types:\n");
> +	printf("%sAvailable backing src types:\n", prefix);
> +
>  	for (i = 0; i < NUM_SRC_TYPES; i++)
> -		printf("\t%s\n", vm_mem_backing_src_alias(i)->name);
> +		printf("%s    %s\n", prefix, vm_mem_backing_src_alias(i)->name);
> +}
> +
> +void backing_src_help(const char *flag)
> +{
> +	printf(" %s: specify the type of memory that should be used to\n"
> +	       "     back the guest data region. (default: %s)\n",
> +	       flag, vm_mem_backing_src_alias(DEFAULT_VM_MEM_SRC)->name);
> +	print_available_backing_src_types("     ");
>  }
>  
>  enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name)
> @@ -296,7 +305,7 @@ enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name)
>  		if (!strcmp(type_name, vm_mem_backing_src_alias(i)->name))
>  			return i;
>  
> -	backing_src_help();
> +	print_available_backing_src_types("");
>  	TEST_FAIL("Unknown backing src type: %s", type_name);
>  	return -1;
>  }
> -- 
> 2.33.0.309.g3052b89438-goog
>


Reviewed-by: Andrew Jones <drjones@redhat.com>

Thanks,
drew