Re: [PATCH v13 08/12] KVM: selftests: Add additional equivalents to libnuma APIs in KVM's numaif.h

["Garg, Shivank" <shivankg@amd.com>]

On 10/16/2025 10:58 PM, Sean Christopherson wrote:
> Add APIs for all syscalls defined in the kernel's mm/mempolicy.c to match
> those that would be provided by linking to libnuma.  Opportunistically use
> the recently inroduced KVM_SYSCALL_DEFINE() builders to take care of the
> boilerplate, and to fix a flaw where the two existing wrappers would
> generate multiple symbols if numaif.h were to be included multiple times.
> 
> Reviewed-by: Ackerley Tng <ackerleytng@google.com>
> Tested-by: Ackerley Tng <ackerleytng@google.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  tools/testing/selftests/kvm/include/numaif.h  | 36 +++++++++++--------
>  .../selftests/kvm/x86/xapic_ipi_test.c        |  5 ++-
>  2 files changed, 23 insertions(+), 18 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/numaif.h b/tools/testing/selftests/kvm/include/numaif.h
> index b020547403fd..aaa4ac174890 100644
> --- a/tools/testing/selftests/kvm/include/numaif.h
> +++ b/tools/testing/selftests/kvm/include/numaif.h
> @@ -13,23 +13,29 @@
>  #ifndef SELFTEST_KVM_NUMAIF_H
>  #define SELFTEST_KVM_NUMAIF_H
>  
> -#define __NR_get_mempolicy 239
> -#define __NR_migrate_pages 256
> +#include <linux/mempolicy.h>
>  
> -/* System calls */
> -long get_mempolicy(int *policy, const unsigned long *nmask,
> -		   unsigned long maxnode, void *addr, int flags)
> -{
> -	return syscall(__NR_get_mempolicy, policy, nmask,
> -		       maxnode, addr, flags);
> -}
> +#include "kvm_syscalls.h"
>  
> -long migrate_pages(int pid, unsigned long maxnode,
> -		   const unsigned long *frommask,
> -		   const unsigned long *tomask)
> -{
> -	return syscall(__NR_migrate_pages, pid, maxnode, frommask, tomask);
> -}
> +KVM_SYSCALL_DEFINE(get_mempolicy, 5, int *, policy, const unsigned long *, nmask,
> +		   unsigned long, maxnode, void *, addr, int, flags);
> +
> +KVM_SYSCALL_DEFINE(set_mempolicy, 3, int, mode, const unsigned long *, nmask,
> +		   unsigned long, maxnode);
> +
> +KVM_SYSCALL_DEFINE(set_mempolicy_home_node, 4, unsigned long, start,
> +		   unsigned long, len, unsigned long, home_node,
> +		   unsigned long, flags);

set_mempolicy_home_node() has no user in this series,
but adding it for API completeness (or future use) looks reasonable to me.

Reviewed-by: Shivank Garg <shivankg@amd.com>
Tested-by: Shivank Garg <shivankg@amd.com>

> +
> +KVM_SYSCALL_DEFINE(migrate_pages, 4, int, pid, unsigned long, maxnode,
> +		   const unsigned long *, frommask, const unsigned long *, tomask);
> +
> +KVM_SYSCALL_DEFINE(move_pages, 6, int, pid, unsigned long, count, void *, pages,
> +		   const int *, nodes, int *, status, int, flags);
> +
> +KVM_SYSCALL_DEFINE(mbind, 6, void *, addr, unsigned long, size, int, mode,
> +		   const unsigned long *, nodemask, unsigned long, maxnode,
> +		   unsigned int, flags);
>  
>  /* Policies */
>  #define MPOL_DEFAULT	 0
> diff --git a/tools/testing/selftests/kvm/x86/xapic_ipi_test.c b/tools/testing/selftests/kvm/x86/xapic_ipi_test.c
> index 35cb9de54a82..ae4a4b6c05ca 100644
> --- a/tools/testing/selftests/kvm/x86/xapic_ipi_test.c
> +++ b/tools/testing/selftests/kvm/x86/xapic_ipi_test.c
> @@ -256,7 +256,7 @@ void do_migrations(struct test_data_page *data, int run_secs, int delay_usecs,
>  	int nodes = 0;
>  	time_t start_time, last_update, now;
>  	time_t interval_secs = 1;
> -	int i, r;
> +	int i;
>  	int from, to;
>  	unsigned long bit;
>  	uint64_t hlt_count;
> @@ -267,9 +267,8 @@ void do_migrations(struct test_data_page *data, int run_secs, int delay_usecs,
>  		delay_usecs);
>  
>  	/* Get set of first 64 numa nodes available */
> -	r = get_mempolicy(NULL, &nodemask, sizeof(nodemask) * 8,
> +	kvm_get_mempolicy(NULL, &nodemask, sizeof(nodemask) * 8,
>  			  0, MPOL_F_MEMS_ALLOWED);
> -	TEST_ASSERT(r == 0, "get_mempolicy failed errno=%d", errno);
>  
>  	fprintf(stderr, "Numa nodes found amongst first %lu possible nodes "
>  		"(each 1-bit indicates node is present): %#lx\n",