2 * Hypervisor supplied "24x7" performance counter support
4 * Author: Cody P Schafer <cody@linux.vnet.ibm.com>
5 * Copyright 2014 IBM Corporation.
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #define pr_fmt(fmt) "hv-24x7: " fmt
15 #include <linux/perf_event.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <asm/firmware.h>
19 #include <asm/hvcall.h>
23 #include "hv-24x7-catalog.h"
24 #include "hv-common.h"
27 * TODO: Merging events:
28 * - Think of the hcall as an interface to a 4d array of counters:
30 * - y = indexes in the domain (core, chip, vcpu, node, etc)
31 * - z = offset into the counter space
32 * - w = lpars (guest vms, "logical partitions")
33 * - A single request is: x,y,y_last,z,z_last,w,w_last
34 * - this means we can retrieve a rectangle of counters in y,z for a single x.
36 * - Things to consider (ignoring w):
37 * - input cost_per_request = 16
38 * - output cost_per_result(ys,zs) = 8 + 8 * ys + ys * zs
39 * - limited number of requests per hcall (must fit into 4K bytes)
40 * - 4k = 16 [buffer header] - 16 [request size] * request_count
41 * - 255 requests per hcall
42 * - sometimes it will be more efficient to read extra data and discard
47 * perf stat -e 'hv_24x7/domain=2,offset=8,starting_index=0,lpar=0xffffffff/'
50 /* u3 0-6, one of HV_24X7_PERF_DOMAIN */
51 EVENT_DEFINE_RANGE_FORMAT(domain
, config
, 0, 3);
53 EVENT_DEFINE_RANGE_FORMAT(starting_index
, config
, 16, 31);
54 /* u32, see "data_offset" */
55 EVENT_DEFINE_RANGE_FORMAT(offset
, config
, 32, 63);
57 EVENT_DEFINE_RANGE_FORMAT(lpar
, config1
, 0, 15);
59 EVENT_DEFINE_RANGE(reserved1
, config
, 4, 15);
60 EVENT_DEFINE_RANGE(reserved2
, config1
, 16, 63);
61 EVENT_DEFINE_RANGE(reserved3
, config2
, 0, 63);
63 static struct attribute
*format_attrs
[] = {
64 &format_attr_domain
.attr
,
65 &format_attr_offset
.attr
,
66 &format_attr_starting_index
.attr
,
67 &format_attr_lpar
.attr
,
71 static struct attribute_group format_group
= {
73 .attrs
= format_attrs
,
76 static struct kmem_cache
*hv_page_cache
;
78 static unsigned long h_get_24x7_catalog_page_(unsigned long phys_4096
,
79 unsigned long version
,
82 pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)",
86 WARN_ON(!IS_ALIGNED(phys_4096
, 4096));
87 return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE
,
93 static unsigned long h_get_24x7_catalog_page(char page
[],
94 u64 version
, u32 index
)
96 return h_get_24x7_catalog_page_(virt_to_phys(page
),
100 static ssize_t
catalog_read(struct file
*filp
, struct kobject
*kobj
,
101 struct bin_attribute
*bin_attr
, char *buf
,
102 loff_t offset
, size_t count
)
106 size_t catalog_len
= 0, catalog_page_len
= 0;
107 loff_t page_offset
= 0;
108 loff_t offset_in_page
;
110 uint64_t catalog_version_num
= 0;
111 void *page
= kmem_cache_alloc(hv_page_cache
, GFP_USER
);
112 struct hv_24x7_catalog_page_0
*page_0
= page
;
116 hret
= h_get_24x7_catalog_page(page
, 0, 0);
122 catalog_version_num
= be64_to_cpu(page_0
->version
);
123 catalog_page_len
= be32_to_cpu(page_0
->length
);
124 catalog_len
= catalog_page_len
* 4096;
126 page_offset
= offset
/ 4096;
127 offset_in_page
= offset
% 4096;
129 if (page_offset
>= catalog_page_len
)
132 if (page_offset
!= 0) {
133 hret
= h_get_24x7_catalog_page(page
, catalog_version_num
,
141 copy_len
= 4096 - offset_in_page
;
142 if (copy_len
> count
)
145 memcpy(buf
, page
+offset_in_page
, copy_len
);
150 pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:"
152 catalog_version_num
, page_offset
, hret
);
153 kmem_cache_free(hv_page_cache
, page
);
155 pr_devel("catalog_read: offset=%lld(%lld) count=%zu "
156 "catalog_len=%zu(%zu) => %zd\n", offset
, page_offset
,
157 count
, catalog_len
, catalog_page_len
, ret
);
162 #define PAGE_0_ATTR(_name, _fmt, _expr) \
163 static ssize_t _name##_show(struct device *dev, \
164 struct device_attribute *dev_attr, \
167 unsigned long hret; \
169 void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \
170 struct hv_24x7_catalog_page_0 *page_0 = page; \
173 hret = h_get_24x7_catalog_page(page, 0, 0); \
178 ret = sprintf(buf, _fmt, _expr); \
183 static DEVICE_ATTR_RO(_name)
185 PAGE_0_ATTR(catalog_version
, "%lld\n",
186 (unsigned long long)be64_to_cpu(page_0
->version
));
187 PAGE_0_ATTR(catalog_len
, "%lld\n",
188 (unsigned long long)be32_to_cpu(page_0
->length
) * 4096);
189 static BIN_ATTR_RO(catalog
, 0/* real length varies */);
191 static struct bin_attribute
*if_bin_attrs
[] = {
196 static struct attribute
*if_attrs
[] = {
197 &dev_attr_catalog_len
.attr
,
198 &dev_attr_catalog_version
.attr
,
202 static struct attribute_group if_group
= {
204 .bin_attrs
= if_bin_attrs
,
208 static const struct attribute_group
*attr_groups
[] = {
214 static bool is_physical_domain(int domain
)
216 return domain
== HV_24X7_PERF_DOMAIN_PHYSICAL_CHIP
||
217 domain
== HV_24X7_PERF_DOMAIN_PHYSICAL_CORE
;
220 static unsigned long single_24x7_request(u8 domain
, u32 offset
, u16 ix
,
222 bool success_expected
)
224 unsigned long ret
= -ENOMEM
;
227 * request_buffer and result_buffer are not required to be 4k aligned,
228 * but are not allowed to cross any 4k boundary. Aligning them to 4k is
229 * the simplest way to ensure that.
232 struct hv_24x7_request_buffer buf
;
233 struct hv_24x7_request req
;
234 } __packed
*request_buffer
;
237 struct hv_24x7_data_result_buffer buf
;
238 struct hv_24x7_result res
;
239 struct hv_24x7_result_element elem
;
241 } __packed
*result_buffer
;
243 BUILD_BUG_ON(sizeof(*request_buffer
) > 4096);
244 BUILD_BUG_ON(sizeof(*result_buffer
) > 4096);
246 request_buffer
= kmem_cache_zalloc(hv_page_cache
, GFP_USER
);
250 result_buffer
= kmem_cache_zalloc(hv_page_cache
, GFP_USER
);
252 goto out_free_request_buffer
;
254 *request_buffer
= (struct reqb
) {
256 .interface_version
= HV_24X7_IF_VERSION_CURRENT
,
260 .performance_domain
= domain
,
261 .data_size
= cpu_to_be16(8),
262 .data_offset
= cpu_to_be32(offset
),
263 .starting_lpar_ix
= cpu_to_be16(lpar
),
264 .max_num_lpars
= cpu_to_be16(1),
265 .starting_ix
= cpu_to_be16(ix
),
266 .max_ix
= cpu_to_be16(1),
270 ret
= plpar_hcall_norets(H_GET_24X7_DATA
,
271 virt_to_phys(request_buffer
), sizeof(*request_buffer
),
272 virt_to_phys(result_buffer
), sizeof(*result_buffer
));
275 if (success_expected
)
276 pr_err_ratelimited("hcall failed: %d %#x %#x %d => "
277 "0x%lx (%ld) detail=0x%x failing ix=%x\n",
278 domain
, offset
, ix
, lpar
, ret
, ret
,
279 result_buffer
->buf
.detailed_rc
,
280 result_buffer
->buf
.failing_request_ix
);
281 goto out_free_result_buffer
;
284 *res
= be64_to_cpu(result_buffer
->result
);
286 out_free_result_buffer
:
287 kfree(result_buffer
);
288 out_free_request_buffer
:
289 kfree(request_buffer
);
294 static unsigned long event_24x7_request(struct perf_event
*event
, u64
*res
,
295 bool success_expected
)
297 return single_24x7_request(event_get_domain(event
),
298 event_get_offset(event
),
299 event_get_starting_index(event
),
300 event_get_lpar(event
),
305 static int h_24x7_event_init(struct perf_event
*event
)
307 struct hv_perf_caps caps
;
313 if (event
->attr
.type
!= event
->pmu
->type
)
316 /* Unused areas must be 0 */
317 if (event_get_reserved1(event
) ||
318 event_get_reserved2(event
) ||
319 event_get_reserved3(event
)) {
320 pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n",
322 event_get_reserved1(event
),
324 event_get_reserved2(event
),
326 event_get_reserved3(event
));
330 /* unsupported modes and filters */
331 if (event
->attr
.exclude_user
||
332 event
->attr
.exclude_kernel
||
333 event
->attr
.exclude_hv
||
334 event
->attr
.exclude_idle
||
335 event
->attr
.exclude_host
||
336 event
->attr
.exclude_guest
)
339 /* no branch sampling */
340 if (has_branch_stack(event
))
343 /* offset must be 8 byte aligned */
344 if (event_get_offset(event
) % 8) {
345 pr_devel("bad alignment\n");
349 /* Domains above 6 are invalid */
350 domain
= event_get_domain(event
);
352 pr_devel("invalid domain %d\n", domain
);
356 hret
= hv_perf_caps_get(&caps
);
358 pr_devel("could not get capabilities: rc=%ld\n", hret
);
362 /* PHYSICAL domains & other lpars require extra capabilities */
363 if (!caps
.collect_privileged
&& (is_physical_domain(domain
) ||
364 (event_get_lpar(event
) != event_get_lpar_max()))) {
365 pr_devel("hv permisions disallow: is_physical_domain:%d, lpar=0x%llx\n",
366 is_physical_domain(domain
),
367 event_get_lpar(event
));
371 /* see if the event complains */
372 if (event_24x7_request(event
, &ct
, false)) {
373 pr_devel("test hcall failed\n");
380 static u64
h_24x7_get_value(struct perf_event
*event
)
384 ret
= event_24x7_request(event
, &ct
, true);
386 /* We checked this in event init, shouldn't fail here... */
392 static void h_24x7_event_update(struct perf_event
*event
)
396 now
= h_24x7_get_value(event
);
397 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
398 local64_add(now
- prev
, &event
->count
);
401 static void h_24x7_event_start(struct perf_event
*event
, int flags
)
403 if (flags
& PERF_EF_RELOAD
)
404 local64_set(&event
->hw
.prev_count
, h_24x7_get_value(event
));
407 static void h_24x7_event_stop(struct perf_event
*event
, int flags
)
409 h_24x7_event_update(event
);
412 static int h_24x7_event_add(struct perf_event
*event
, int flags
)
414 if (flags
& PERF_EF_START
)
415 h_24x7_event_start(event
, flags
);
420 static struct pmu h_24x7_pmu
= {
421 .task_ctx_nr
= perf_invalid_context
,
424 .attr_groups
= attr_groups
,
425 .event_init
= h_24x7_event_init
,
426 .add
= h_24x7_event_add
,
427 .del
= h_24x7_event_stop
,
428 .start
= h_24x7_event_start
,
429 .stop
= h_24x7_event_stop
,
430 .read
= h_24x7_event_update
,
433 static int hv_24x7_init(void)
437 struct hv_perf_caps caps
;
439 if (!firmware_has_feature(FW_FEATURE_LPAR
)) {
440 pr_debug("not a virtualized system, not enabling\n");
444 hret
= hv_perf_caps_get(&caps
);
446 pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
451 hv_page_cache
= kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL
);
455 /* sampling not supported */
456 h_24x7_pmu
.capabilities
|= PERF_PMU_CAP_NO_INTERRUPT
;
458 r
= perf_pmu_register(&h_24x7_pmu
, h_24x7_pmu
.name
, -1);
465 device_initcall(hv_24x7_init
);