xref: /openbmc/qemu/contrib/plugins/hotpages.c (revision 6f03770d)
1 /*
2  * Copyright (C) 2019, Alex Bennée <alex.bennee@linaro.org>
3  *
4  * Hot Pages - show which pages saw the most memory accesses.
5  *
6  * License: GNU GPL, version 2 or later.
7  *   See the COPYING file in the top-level directory.
8  */
9 
10 #include <inttypes.h>
11 #include <assert.h>
12 #include <stdlib.h>
13 #include <inttypes.h>
14 #include <string.h>
15 #include <unistd.h>
16 #include <stdio.h>
17 #include <glib.h>
18 
19 #include <qemu-plugin.h>
20 
21 QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
22 
23 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
24 
25 static uint64_t page_size = 4096;
26 static uint64_t page_mask;
27 static int limit = 50;
28 static enum qemu_plugin_mem_rw rw = QEMU_PLUGIN_MEM_RW;
29 static bool track_io;
30 
31 enum sort_type {
32     SORT_RW = 0,
33     SORT_R,
34     SORT_W,
35     SORT_A
36 };
37 
38 static int sort_by = SORT_RW;
39 
40 typedef struct {
41     uint64_t page_address;
42     int cpu_read;
43     int cpu_write;
44     uint64_t reads;
45     uint64_t writes;
46 } PageCounters;
47 
48 static GMutex lock;
49 static GHashTable *pages;
50 
51 static gint cmp_access_count(gconstpointer a, gconstpointer b)
52 {
53     PageCounters *ea = (PageCounters *) a;
54     PageCounters *eb = (PageCounters *) b;
55     int r;
56     switch (sort_by) {
57     case SORT_RW:
58         r = (ea->reads + ea->writes) > (eb->reads + eb->writes) ? -1 : 1;
59         break;
60     case SORT_R:
61         r = ea->reads > eb->reads ? -1 : 1;
62         break;
63     case SORT_W:
64         r = ea->writes > eb->writes ? -1 : 1;
65         break;
66     case SORT_A:
67         r = ea->page_address > eb->page_address ? -1 : 1;
68         break;
69     default:
70         g_assert_not_reached();
71     }
72     return r;
73 }
74 
75 
76 static void plugin_exit(qemu_plugin_id_t id, void *p)
77 {
78     g_autoptr(GString) report = g_string_new("Addr, RCPUs, Reads, WCPUs, Writes\n");
79     int i;
80     GList *counts;
81 
82     counts = g_hash_table_get_values(pages);
83     if (counts && g_list_next(counts)) {
84         GList *it;
85 
86         it = g_list_sort(counts, cmp_access_count);
87 
88         for (i = 0; i < limit && it->next; i++, it = it->next) {
89             PageCounters *rec = (PageCounters *) it->data;
90             g_string_append_printf(report,
91                                    "0x%016"PRIx64", 0x%04x, %"PRId64
92                                    ", 0x%04x, %"PRId64"\n",
93                                    rec->page_address,
94                                    rec->cpu_read, rec->reads,
95                                    rec->cpu_write, rec->writes);
96         }
97         g_list_free(it);
98     }
99 
100     qemu_plugin_outs(report->str);
101 }
102 
103 static void plugin_init(void)
104 {
105     page_mask = (page_size - 1);
106     pages = g_hash_table_new(NULL, g_direct_equal);
107 }
108 
109 static void vcpu_haddr(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
110                        uint64_t vaddr, void *udata)
111 {
112     struct qemu_plugin_hwaddr *hwaddr = qemu_plugin_get_hwaddr(meminfo, vaddr);
113     uint64_t page;
114     PageCounters *count;
115 
116     /* We only get a hwaddr for system emulation */
117     if (track_io) {
118         if (hwaddr && qemu_plugin_hwaddr_is_io(hwaddr)) {
119             page = vaddr;
120         } else {
121             return;
122         }
123     } else {
124         if (hwaddr && !qemu_plugin_hwaddr_is_io(hwaddr)) {
125             page = (uint64_t) qemu_plugin_hwaddr_device_offset(hwaddr);
126         } else {
127             page = vaddr;
128         }
129     }
130     page &= ~page_mask;
131 
132     g_mutex_lock(&lock);
133     count = (PageCounters *) g_hash_table_lookup(pages, GUINT_TO_POINTER(page));
134 
135     if (!count) {
136         count = g_new0(PageCounters, 1);
137         count->page_address = page;
138         g_hash_table_insert(pages, GUINT_TO_POINTER(page), (gpointer) count);
139     }
140     if (qemu_plugin_mem_is_store(meminfo)) {
141         count->writes++;
142         count->cpu_write |= (1 << cpu_index);
143     } else {
144         count->reads++;
145         count->cpu_read |= (1 << cpu_index);
146     }
147 
148     g_mutex_unlock(&lock);
149 }
150 
151 static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
152 {
153     size_t n = qemu_plugin_tb_n_insns(tb);
154     size_t i;
155 
156     for (i = 0; i < n; i++) {
157         struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i);
158         qemu_plugin_register_vcpu_mem_cb(insn, vcpu_haddr,
159                                          QEMU_PLUGIN_CB_NO_REGS,
160                                          rw, NULL);
161     }
162 }
163 
164 QEMU_PLUGIN_EXPORT
165 int qemu_plugin_install(qemu_plugin_id_t id, const qemu_info_t *info,
166                         int argc, char **argv)
167 {
168     int i;
169 
170     for (i = 0; i < argc; i++) {
171         char *opt = argv[i];
172         if (g_strcmp0(opt, "reads") == 0) {
173             sort_by = SORT_R;
174         } else if (g_strcmp0(opt, "writes") == 0) {
175             sort_by = SORT_W;
176         } else if (g_strcmp0(opt, "address") == 0) {
177             sort_by = SORT_A;
178         } else if (g_strcmp0(opt, "io") == 0) {
179             track_io = true;
180         } else if (g_str_has_prefix(opt, "pagesize=")) {
181             page_size = g_ascii_strtoull(opt + 9, NULL, 10);
182         } else {
183             fprintf(stderr, "option parsing failed: %s\n", opt);
184             return -1;
185         }
186     }
187 
188     plugin_init();
189 
190     qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans);
191     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
192     return 0;
193 }
194