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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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1/* SPDX-License-Identifier: GPL-2.0-only */
2/* Copyright (C) 2020, Google LLC. */
3
4#ifndef SELFTEST_KVM_NUMAIF_H
5#define SELFTEST_KVM_NUMAIF_H
6
7#include <dirent.h>
8
9#include <linux/mempolicy.h>
10
11#include "kvm_syscalls.h"
12
13KVM_SYSCALL_DEFINE(get_mempolicy, 5, int *, policy, const unsigned long *, nmask,
14 unsigned long, maxnode, void *, addr, int, flags);
15
16KVM_SYSCALL_DEFINE(set_mempolicy, 3, int, mode, const unsigned long *, nmask,
17 unsigned long, maxnode);
18
19KVM_SYSCALL_DEFINE(set_mempolicy_home_node, 4, unsigned long, start,
20 unsigned long, len, unsigned long, home_node,
21 unsigned long, flags);
22
23KVM_SYSCALL_DEFINE(migrate_pages, 4, int, pid, unsigned long, maxnode,
24 const unsigned long *, frommask, const unsigned long *, tomask);
25
26KVM_SYSCALL_DEFINE(move_pages, 6, int, pid, unsigned long, count, void *, pages,
27 const int *, nodes, int *, status, int, flags);
28
29KVM_SYSCALL_DEFINE(mbind, 6, void *, addr, unsigned long, size, int, mode,
30 const unsigned long *, nodemask, unsigned long, maxnode,
31 unsigned int, flags);
32
33static inline int get_max_numa_node(void)
34{
35 struct dirent *de;
36 int max_node = 0;
37 DIR *d;
38
39 /*
40 * Assume there's a single node if the kernel doesn't support NUMA,
41 * or if no nodes are found.
42 */
43 d = opendir("/sys/devices/system/node");
44 if (!d)
45 return 0;
46
47 while ((de = readdir(d)) != NULL) {
48 int node_id;
49 char *endptr;
50
51 if (strncmp(de->d_name, "node", 4) != 0)
52 continue;
53
54 node_id = strtol(de->d_name + 4, &endptr, 10);
55 if (*endptr != '\0')
56 continue;
57
58 if (node_id > max_node)
59 max_node = node_id;
60 }
61 closedir(d);
62
63 return max_node;
64}
65
66static bool is_numa_available(void)
67{
68 /*
69 * Probe for NUMA by doing a dummy get_mempolicy(). If the syscall
70 * fails with ENOSYS, then the kernel was built without NUMA support.
71 * if the syscall fails with EPERM, then the process/user lacks the
72 * necessary capabilities (CAP_SYS_NICE).
73 */
74 return !get_mempolicy(NULL, NULL, 0, NULL, 0) ||
75 (errno != ENOSYS && errno != EPERM);
76}
77
78static inline bool is_multi_numa_node_system(void)
79{
80 return is_numa_available() && get_max_numa_node() >= 1;
81}
82
83#endif /* SELFTEST_KVM_NUMAIF_H */