/* * Hypervisor supplied "24x7" performance counter support * * Author: Cody P Schafer * Copyright 2014 IBM Corporation. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #define pr_fmt(fmt) "hv-24x7: " fmt #include #include #include #include #include #include #include "hv-24x7.h" #include "hv-24x7-catalog.h" #include "hv-common.h" /* * TODO: Merging events: * - Think of the hcall as an interface to a 4d array of counters: * - x = domains * - y = indexes in the domain (core, chip, vcpu, node, etc) * - z = offset into the counter space * - w = lpars (guest vms, "logical partitions") * - A single request is: x,y,y_last,z,z_last,w,w_last * - this means we can retrieve a rectangle of counters in y,z for a single x. * * - Things to consider (ignoring w): * - input cost_per_request = 16 * - output cost_per_result(ys,zs) = 8 + 8 * ys + ys * zs * - limited number of requests per hcall (must fit into 4K bytes) * - 4k = 16 [buffer header] - 16 [request size] * request_count * - 255 requests per hcall * - sometimes it will be more efficient to read extra data and discard */ /* * Example usage: * perf stat -e 'hv_24x7/domain=2,offset=8,starting_index=0,lpar=0xffffffff/' */ /* u3 0-6, one of HV_24X7_PERF_DOMAIN */ EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3); /* u16 */ EVENT_DEFINE_RANGE_FORMAT(starting_index, config, 16, 31); /* u32, see "data_offset" */ EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63); /* u16 */ EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15); EVENT_DEFINE_RANGE(reserved1, config, 4, 15); EVENT_DEFINE_RANGE(reserved2, config1, 16, 63); EVENT_DEFINE_RANGE(reserved3, config2, 0, 63); static struct attribute *format_attrs[] = { &format_attr_domain.attr, &format_attr_offset.attr, &format_attr_starting_index.attr, &format_attr_lpar.attr, NULL, }; static struct attribute_group format_group = { .name = "format", .attrs = format_attrs, }; static struct kmem_cache *hv_page_cache; /* * read_offset_data - copy data from one buffer to another while treating the * source buffer as a small view on the total avaliable * source data. * * @dest: buffer to copy into * @dest_len: length of @dest in bytes * @requested_offset: the offset within the source data we want. Must be > 0 * @src: buffer to copy data from * @src_len: length of @src in bytes * @source_offset: the offset in the sorce data that (src,src_len) refers to. * Must be > 0 * * returns the number of bytes copied. * * The following ascii art shows the various buffer possitioning we need to * handle, assigns some arbitrary varibles to points on the buffer, and then * shows how we fiddle with those values to get things we care about (copy * start in src and copy len) * * s = @src buffer * d = @dest buffer * '.' areas in d are written to. * * u * x w v z * d |.........| * s |----------------------| * * u * x w z v * d |........------| * s |------------------| * * x w u,z,v * d |........| * s |------------------| * * x,w u,v,z * d |..................| * s |------------------| * * x u * w v z * d |........| * s |------------------| * * x z w v * d |------| * s |------| * * x = source_offset * w = requested_offset * z = source_offset + src_len * v = requested_offset + dest_len * * w_offset_in_s = w - x = requested_offset - source_offset * z_offset_in_s = z - x = src_len * v_offset_in_s = v - x = request_offset + dest_len - src_len */ static ssize_t read_offset_data(void *dest, size_t dest_len, loff_t requested_offset, void *src, size_t src_len, loff_t source_offset) { size_t w_offset_in_s = requested_offset - source_offset; size_t z_offset_in_s = src_len; size_t v_offset_in_s = requested_offset + dest_len - src_len; size_t u_offset_in_s = min(z_offset_in_s, v_offset_in_s); size_t copy_len = u_offset_in_s - w_offset_in_s; if (requested_offset < 0 || source_offset < 0) return -EINVAL; if (z_offset_in_s <= w_offset_in_s) return 0; memcpy(dest, src + w_offset_in_s, copy_len); return copy_len; } static unsigned long h_get_24x7_catalog_page(char page[static 4096], u32 version, u32 index) { WARN_ON(!IS_ALIGNED((unsigned long)page, 4096)); return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE, virt_to_phys(page), version, index); } static ssize_t catalog_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t offset, size_t count) { unsigned long hret; ssize_t ret = 0; size_t catalog_len = 0, catalog_page_len = 0, page_count = 0; loff_t page_offset = 0; uint32_t catalog_version_num = 0; void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); struct hv_24x7_catalog_page_0 *page_0 = page; if (!page) return -ENOMEM; hret = h_get_24x7_catalog_page(page, 0, 0); if (hret) { ret = -EIO; goto e_free; } catalog_version_num = be32_to_cpu(page_0->version); catalog_page_len = be32_to_cpu(page_0->length); catalog_len = catalog_page_len * 4096; page_offset = offset / 4096; page_count = count / 4096; if (page_offset >= catalog_page_len) goto e_free; if (page_offset != 0) { hret = h_get_24x7_catalog_page(page, catalog_version_num, page_offset); if (hret) { ret = -EIO; goto e_free; } } ret = read_offset_data(buf, count, offset, page, 4096, page_offset * 4096); e_free: if (hret) pr_err("h_get_24x7_catalog_page(ver=%d, page=%lld) failed: rc=%ld\n", catalog_version_num, page_offset, hret); kfree(page); pr_devel("catalog_read: offset=%lld(%lld) count=%zu(%zu) catalog_len=%zu(%zu) => %zd\n", offset, page_offset, count, page_count, catalog_len, catalog_page_len, ret); return ret; } #define PAGE_0_ATTR(_name, _fmt, _expr) \ static ssize_t _name##_show(struct device *dev, \ struct device_attribute *dev_attr, \ char *buf) \ { \ unsigned long hret; \ ssize_t ret = 0; \ void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \ struct hv_24x7_catalog_page_0 *page_0 = page; \ if (!page) \ return -ENOMEM; \ hret = h_get_24x7_catalog_page(page, 0, 0); \ if (hret) { \ ret = -EIO; \ goto e_free; \ } \ ret = sprintf(buf, _fmt, _expr); \ e_free: \ kfree(page); \ return ret; \ } \ static DEVICE_ATTR_RO(_name) PAGE_0_ATTR(catalog_version, "%lld\n", (unsigned long long)be32_to_cpu(page_0->version)); PAGE_0_ATTR(catalog_len, "%lld\n", (unsigned long long)be32_to_cpu(page_0->length) * 4096); static BIN_ATTR_RO(catalog, 0/* real length varies */); static struct bin_attribute *if_bin_attrs[] = { &bin_attr_catalog, NULL, }; static struct attribute *if_attrs[] = { &dev_attr_catalog_len.attr, &dev_attr_catalog_version.attr, NULL, }; static struct attribute_group if_group = { .name = "interface", .bin_attrs = if_bin_attrs, .attrs = if_attrs, }; static const struct attribute_group *attr_groups[] = { &format_group, &if_group, NULL, }; static bool is_physical_domain(int domain) { return domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CHIP || domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CORE; } static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix, u16 lpar, u64 *res, bool success_expected) { unsigned long ret; /* * request_buffer and result_buffer are not required to be 4k aligned, * but are not allowed to cross any 4k boundary. Aligning them to 4k is * the simplest way to ensure that. */ struct reqb { struct hv_24x7_request_buffer buf; struct hv_24x7_request req; } __packed __aligned(4096) request_buffer = { .buf = { .interface_version = HV_24X7_IF_VERSION_CURRENT, .num_requests = 1, }, .req = { .performance_domain = domain, .data_size = cpu_to_be16(8), .data_offset = cpu_to_be32(offset), .starting_lpar_ix = cpu_to_be16(lpar), .max_num_lpars = cpu_to_be16(1), .starting_ix = cpu_to_be16(ix), .max_ix = cpu_to_be16(1), } }; struct resb { struct hv_24x7_data_result_buffer buf; struct hv_24x7_result res; struct hv_24x7_result_element elem; __be64 result; } __packed __aligned(4096) result_buffer = {}; ret = plpar_hcall_norets(H_GET_24X7_DATA, virt_to_phys(&request_buffer), sizeof(request_buffer), virt_to_phys(&result_buffer), sizeof(result_buffer)); if (ret) { if (success_expected) pr_err_ratelimited("hcall failed: %d %#x %#x %d => 0x%lx (%ld) detail=0x%x failing ix=%x\n", domain, offset, ix, lpar, ret, ret, result_buffer.buf.detailed_rc, result_buffer.buf.failing_request_ix); return ret; } *res = be64_to_cpu(result_buffer.result); return ret; } static unsigned long event_24x7_request(struct perf_event *event, u64 *res, bool success_expected) { return single_24x7_request(event_get_domain(event), event_get_offset(event), event_get_starting_index(event), event_get_lpar(event), res, success_expected); } static int h_24x7_event_init(struct perf_event *event) { struct hv_perf_caps caps; unsigned domain; unsigned long hret; u64 ct; /* Not our event */ if (event->attr.type != event->pmu->type) return -ENOENT; /* Unused areas must be 0 */ if (event_get_reserved1(event) || event_get_reserved2(event) || event_get_reserved3(event)) { pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n", event->attr.config, event_get_reserved1(event), event->attr.config1, event_get_reserved2(event), event->attr.config2, event_get_reserved3(event)); return -EINVAL; } /* unsupported modes and filters */ if (event->attr.exclude_user || event->attr.exclude_kernel || event->attr.exclude_hv || event->attr.exclude_idle || event->attr.exclude_host || event->attr.exclude_guest || is_sampling_event(event)) /* no sampling */ return -EINVAL; /* no branch sampling */ if (has_branch_stack(event)) return -EOPNOTSUPP; /* offset must be 8 byte aligned */ if (event_get_offset(event) % 8) { pr_devel("bad alignment\n"); return -EINVAL; } /* Domains above 6 are invalid */ domain = event_get_domain(event); if (domain > 6) { pr_devel("invalid domain %d\n", domain); return -EINVAL; } hret = hv_perf_caps_get(&caps); if (hret) { pr_devel("could not get capabilities: rc=%ld\n", hret); return -EIO; } /* PHYSICAL domains & other lpars require extra capabilities */ if (!caps.collect_privileged && (is_physical_domain(domain) || (event_get_lpar(event) != event_get_lpar_max()))) { pr_devel("hv permisions disallow: is_physical_domain:%d, lpar=0x%llx\n", is_physical_domain(domain), event_get_lpar(event)); return -EACCES; } /* see if the event complains */ if (event_24x7_request(event, &ct, false)) { pr_devel("test hcall failed\n"); return -EIO; } return 0; } static u64 h_24x7_get_value(struct perf_event *event) { unsigned long ret; u64 ct; ret = event_24x7_request(event, &ct, true); if (ret) /* We checked this in event init, shouldn't fail here... */ return 0; return ct; } static void h_24x7_event_update(struct perf_event *event) { s64 prev; u64 now; now = h_24x7_get_value(event); prev = local64_xchg(&event->hw.prev_count, now); local64_add(now - prev, &event->count); } static void h_24x7_event_start(struct perf_event *event, int flags) { if (flags & PERF_EF_RELOAD) local64_set(&event->hw.prev_count, h_24x7_get_value(event)); } static void h_24x7_event_stop(struct perf_event *event, int flags) { h_24x7_event_update(event); } static int h_24x7_event_add(struct perf_event *event, int flags) { if (flags & PERF_EF_START) h_24x7_event_start(event, flags); return 0; } static int h_24x7_event_idx(struct perf_event *event) { return 0; } static struct pmu h_24x7_pmu = { .task_ctx_nr = perf_invalid_context, .name = "hv_24x7", .attr_groups = attr_groups, .event_init = h_24x7_event_init, .add = h_24x7_event_add, .del = h_24x7_event_stop, .start = h_24x7_event_start, .stop = h_24x7_event_stop, .read = h_24x7_event_update, .event_idx = h_24x7_event_idx, }; static int hv_24x7_init(void) { int r; unsigned long hret; struct hv_perf_caps caps; if (!firmware_has_feature(FW_FEATURE_LPAR)) { pr_debug("not a virtualized system, not enabling\n"); return -ENODEV; } hret = hv_perf_caps_get(&caps); if (hret) { pr_debug("could not obtain capabilities, not enabling, rc=%ld\n", hret); return -ENODEV; } hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL); if (!hv_page_cache) return -ENOMEM; r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1); if (r) return r; return 0; } device_initcall(hv_24x7_init);