/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #pragma ident "%Z%%M% %I% %E% SMI" /* * Xen event provider for DTrace * * NOTE: This provider is PRIVATE. It is intended as a short-term solution and * may disappear or be re-implemented at anytime. * * This provider isn't suitable as a general-purpose solution for a number of * reasons. First and foremost, we rely on the Xen tracing mechanism and don't * have any way to gather data other than that collected by the Xen trace * buffers. Further, it does not fit into the DTrace model (see "Interacting * with DTrace" below.) * * * Tracing in Xen * -------------- * * Xen implements a tracing facility for generating and collecting execution * event traces from the hypervisor. When tracing is enabled, compiled in * probes record events in contiguous per-CPU trace buffers. * * +---------+ * +------+ | | * | CPUn |----> | BUFFERn | * +------+ | | * +---------+- tbuf.va + (tbuf.size * n) * : : * +---------+ * +------+ | | * | CPU1 |----> | BUFFER1 | * +------+ | | * +---------+- tbuf.va + tbuf.size * +------+ | | * | CPU0 |----> | BUFFER0 | * +------+ | | * +---------+- tbuf.va * * Each CPU buffer consists of a metadata header followed by the trace records. * The metadata consists of a producer/consumer pair of pointers into the buffer * that point to the next record to be written and the next record to be read * respectively. The trace record format is as follows: * * +--------------------------------------------------------------------------+ * | CPUID(uint_t) | TSC(uint64_t) | EVENTID(uint32_t) | DATA FIELDS | * +--------------------------------------------------------------------------+ * * DATA FIELDS: * +--------------------------------------------------------------------------+ * | D1(uint32_t) | D2(uint32_t) | D3(uint32_t) | D4(uint32_t) | D5(uint32_t) | * +--------------------------------------------------------------------------+ * * * Interacting with DTrace * ----------------------- * * Every xdt_poll_nsec nano-seconds we poll the trace buffers for data and feed * each entry into dtrace_probe() with the corresponding probe ID for the event. * As a result of this periodic collection implementation probe firings are * asynchronous. This is the only sensible way to implement this form of * provider, but because of its asynchronous nature asking things like * "current CPU" and, more importantly, arbitrary questions about the context * surrounding the probe firing are not meaningful. So, consumers should not * attempt to infer anything beyond what is supplied via the probe arguments. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define XDT_POLL_DEFAULT 100000000 /* default poll interval (ns) */ #define XDT_POLL_MIN 10000000 /* min poll interval (ns) */ #define XDT_TBUF_RETRY 50 /* tbuf disable retry count */ /* * The domid must match IDLE_DOMAIN_ID in xen.hg/xen/include/xen/sched.h * in the xVM gate. */ #define IS_IDLE_DOM(domid) (domid == 0x7FFFU) /* Macros to extract the domid and cpuid from a HVM trace data field */ #define HVM_DOMID(d) (d >> 16) #define HVM_VCPUID(d) (d & 0xFFFF) #define XDT_PROBE4(event, cpuid, arg0, arg1, arg2, arg3) { \ dtrace_id_t id = xdt_probemap[event]; \ if (id) \ dtrace_probe(id, cpuid, arg0, arg1, arg2, arg3); \ } \ #define XDT_PROBE3(event, cpuid, arg0, arg1, arg2) \ XDT_PROBE4(event, cpuid, arg0, arg1, arg2, 0) #define XDT_PROBE2(event, cpuid, arg0, arg1) \ XDT_PROBE4(event, cpuid, arg0, arg1, 0, 0) #define XDT_PROBE1(event, cpuid, arg0) \ XDT_PROBE4(event, cpuid, arg0, 0, 0, 0) #define XDT_PROBE0(event, cpuid) \ XDT_PROBE4(event, cpuid, 0, 0, 0, 0) /* Probe classes */ #define XDT_SCHED 0 #define XDT_MEM 1 #define XDT_HVM 2 #define XDT_NCLASSES 3 /* Probe events */ #define XDT_EVT_INVALID (-(int)1) #define XDT_SCHED_OFF_CPU 0 #define XDT_SCHED_ON_CPU 1 #define XDT_SCHED_IDLE_OFF_CPU 2 #define XDT_SCHED_IDLE_ON_CPU 3 #define XDT_SCHED_BLOCK 4 #define XDT_SCHED_SLEEP 5 #define XDT_SCHED_WAKE 6 #define XDT_SCHED_YIELD 7 #define XDT_SCHED_SHUTDOWN_POWEROFF 8 #define XDT_SCHED_SHUTDOWN_REBOOT 9 #define XDT_SCHED_SHUTDOWN_SUSPEND 10 #define XDT_SCHED_SHUTDOWN_CRASH 11 #define XDT_MEM_PAGE_GRANT_MAP 12 #define XDT_MEM_PAGE_GRANT_UNMAP 13 #define XDT_MEM_PAGE_GRANT_TRANSFER 14 #define XDT_HVM_VMENTRY 15 #define XDT_HVM_VMEXIT 16 #define XDT_NEVENTS 17 typedef struct { const char *pr_mod; /* probe module */ const char *pr_name; /* probe name */ int evt_id; /* event id */ uint_t class; /* probe class */ } xdt_probe_t; typedef struct { uint32_t trc_mask; /* trace mask */ uint32_t cnt; /* num enabled probes in class */ } xdt_classinfo_t; typedef struct { ulong_t prev_domid; /* previous dom executed */ ulong_t prev_vcpuid; /* previous vcpu executed */ ulong_t prev_ctime; /* time spent on cpu */ ulong_t next_domid; /* next dom to be scheduled */ ulong_t next_vcpuid; /* next vcpu to be scheduled */ ulong_t next_wtime; /* time spent waiting to get on cpu */ ulong_t next_ts; /* allocated time slice */ } xdt_schedinfo_t; static struct { uint_t cnt; /* total num of trace buffers */ size_t size; /* size of each cpu buffer */ mfn_t start_mfn; /* starting mfn of buffers */ caddr_t va; /* va buffers are mapped into */ /* per-cpu buffers */ struct t_buf **meta; /* buffer metadata */ struct t_rec **data; /* buffer data records */ /* statistics */ uint64_t stat_dropped_recs; /* records dropped */ uint64_t stat_spurious_cpu; /* recs with garbage cpuids */ uint64_t stat_spurious_switch; /* inconsistent vcpu switches */ uint64_t stat_unknown_shutdown; /* unknown shutdown code */ uint64_t stat_unknown_recs; /* unknown records */ } tbuf; static char *xdt_stats[] = { "dropped_recs", }; /* * Tunable variables * * The following may be tuned by adding a line to /etc/system that * includes both the name of the module ("xdt") and the name of the variable. * For example: * set xdt:xdt_tbuf_pages = 40 */ uint_t xdt_tbuf_pages = 20; /* pages to alloc per-cpu buf */ /* * The following may be tuned by adding a line to * /platform/i86xpv/kernel/drv/xdt.conf. * For example: * xdt_poll_nsec = 200000000; */ static hrtime_t xdt_poll_nsec; /* trace buffer poll interval */ /* * Internal variables */ static dev_info_t *xdt_devi; static dtrace_provider_id_t xdt_id; static uint_t xdt_ncpus; /* total number of phys CPUs */ static uint32_t cur_trace_mask; /* current trace mask */ static xdt_schedinfo_t *xdt_cpu_schedinfo; /* per-cpu sched info */ dtrace_id_t xdt_probemap[XDT_NEVENTS]; /* map of enabled probes */ dtrace_id_t xdt_prid[XDT_NEVENTS]; /* IDs of registered events */ static cyclic_id_t xdt_cyclic = CYCLIC_NONE; static kstat_t *xdt_kstats; static xdt_classinfo_t xdt_classinfo[XDT_NCLASSES]; static xdt_probe_t xdt_probe[] = { /* Sched probes */ { "sched", "off-cpu", XDT_SCHED_OFF_CPU, XDT_SCHED }, { "sched", "on-cpu", XDT_SCHED_ON_CPU, XDT_SCHED }, { "sched", "idle-off-cpu", XDT_SCHED_IDLE_OFF_CPU, XDT_SCHED }, { "sched", "idle-on-cpu", XDT_SCHED_IDLE_ON_CPU, XDT_SCHED }, { "sched", "block", XDT_SCHED_BLOCK, XDT_SCHED }, { "sched", "sleep", XDT_SCHED_SLEEP, XDT_SCHED }, { "sched", "wake", XDT_SCHED_WAKE, XDT_SCHED }, { "sched", "yield", XDT_SCHED_YIELD, XDT_SCHED }, { "sched", "shutdown-poweroff", XDT_SCHED_SHUTDOWN_POWEROFF, XDT_SCHED }, { "sched", "shutdown-reboot", XDT_SCHED_SHUTDOWN_REBOOT, XDT_SCHED }, { "sched", "shutdown-suspend", XDT_SCHED_SHUTDOWN_SUSPEND, XDT_SCHED }, { "sched", "shutdown-crash", XDT_SCHED_SHUTDOWN_CRASH, XDT_SCHED }, /* Memory probes */ { "mem", "page-grant-map", XDT_MEM_PAGE_GRANT_MAP, XDT_MEM }, { "mem", "page-grant-unmap", XDT_MEM_PAGE_GRANT_UNMAP, XDT_MEM }, { "mem", "page-grant-transfer", XDT_MEM_PAGE_GRANT_TRANSFER, XDT_MEM }, /* HVM probes */ { "hvm", "vmentry", XDT_HVM_VMENTRY, XDT_HVM }, { "hvm", "vmexit", XDT_HVM_VMEXIT, XDT_HVM }, { NULL } }; extern uint_t xen_get_nphyscpus(void); static inline uint32_t xdt_nr_active_probes() { int i; uint32_t tot = 0; for (i = 0; i < XDT_NCLASSES; i++) tot += xdt_classinfo[i].cnt; return (tot); } static void xdt_init_trace_masks(void) { xdt_classinfo[XDT_SCHED].trc_mask = TRC_SCHED; xdt_classinfo[XDT_MEM].trc_mask = TRC_MEM; xdt_classinfo[XDT_HVM].trc_mask = TRC_HVM; } static int xdt_kstat_update(kstat_t *ksp, int flag) { kstat_named_t *knp; if (flag != KSTAT_READ) return (EACCES); knp = ksp->ks_data; /* * Assignment order should match that of the names in * xdt_stats. */ (knp++)->value.ui64 = tbuf.stat_dropped_recs; return (0); } static void xdt_kstat_init(void) { int nstats = sizeof (xdt_stats) / sizeof (xdt_stats[0]); char **cp = xdt_stats; kstat_named_t *knp; if ((xdt_kstats = kstat_create("xdt", 0, "trace_statistics", "misc", KSTAT_TYPE_NAMED, nstats, 0)) == NULL) return; xdt_kstats->ks_update = xdt_kstat_update; knp = xdt_kstats->ks_data; while (nstats > 0) { kstat_named_init(knp, *cp, KSTAT_DATA_UINT64); knp++; cp++; nstats--; } kstat_install(xdt_kstats); } static int xdt_sysctl_tbuf(xen_sysctl_tbuf_op_t *tbuf_op) { xen_sysctl_t op; int xerr; op.cmd = XEN_SYSCTL_tbuf_op; op.interface_version = XEN_SYSCTL_INTERFACE_VERSION; op.u.tbuf_op = *tbuf_op; if ((xerr = HYPERVISOR_sysctl(&op)) != 0) return (xen_xlate_errcode(xerr)); *tbuf_op = op.u.tbuf_op; return (0); } static int xdt_map_trace_buffers(mfn_t mfn, caddr_t va, size_t len) { x86pte_t pte; caddr_t const sva = va; caddr_t const eva = va + len; int xerr; ASSERT(mfn != MFN_INVALID); ASSERT(va != NULL); ASSERT(IS_PAGEALIGNED(len)); for (; va < eva; va += MMU_PAGESIZE) { /* * Ask the HAT to load a throwaway mapping to page zero, then * overwrite it with the hypervisor mapping. It gets removed * later via hat_unload(). */ hat_devload(kas.a_hat, va, MMU_PAGESIZE, (pfn_t)0, PROT_READ | HAT_UNORDERED_OK, HAT_LOAD_NOCONSIST | HAT_LOAD); pte = mmu_ptob((x86pte_t)mfn) | PT_VALID | PT_USER | PT_FOREIGN | PT_WRITABLE; xerr = HYPERVISOR_update_va_mapping_otherdomain((ulong_t)va, pte, UVMF_INVLPG | UVMF_LOCAL, DOMID_XEN); if (xerr != 0) { /* unmap pages loaded so far */ size_t ulen = (uintptr_t)(va + MMU_PAGESIZE) - (uintptr_t)sva; hat_unload(kas.a_hat, sva, ulen, HAT_UNLOAD_UNMAP); return (xen_xlate_errcode(xerr)); } mfn++; } return (0); } static int xdt_attach_trace_buffers(void) { xen_sysctl_tbuf_op_t tbuf_op; size_t len; int err; uint_t i; /* set trace buffer size */ tbuf_op.cmd = XEN_SYSCTL_TBUFOP_set_size; tbuf_op.size = xdt_tbuf_pages; (void) xdt_sysctl_tbuf(&tbuf_op); /* get trace buffer info */ tbuf_op.cmd = XEN_SYSCTL_TBUFOP_get_info; if ((err = xdt_sysctl_tbuf(&tbuf_op)) != 0) return (err); tbuf.size = tbuf_op.size; tbuf.start_mfn = (mfn_t)tbuf_op.buffer_mfn; tbuf.cnt = xdt_ncpus; if (tbuf.size == 0) { cmn_err(CE_NOTE, "No trace buffers allocated!"); return (ENOBUFS); } ASSERT(tbuf.start_mfn != MFN_INVALID); ASSERT(tbuf.cnt > 0); len = tbuf.size * tbuf.cnt; tbuf.va = vmem_alloc(heap_arena, len, VM_SLEEP); if ((err = xdt_map_trace_buffers(tbuf.start_mfn, tbuf.va, len)) != 0) { vmem_free(heap_arena, tbuf.va, len); tbuf.va = NULL; return (err); } tbuf.meta = (struct t_buf **)kmem_alloc(tbuf.cnt * sizeof (*tbuf.meta), KM_SLEEP); tbuf.data = (struct t_rec **)kmem_alloc(tbuf.cnt * sizeof (*tbuf.data), KM_SLEEP); for (i = 0; i < tbuf.cnt; i++) { void *cpu_buf = (void *)(tbuf.va + (tbuf.size * i)); tbuf.meta[i] = cpu_buf; tbuf.data[i] = (struct t_rec *)((uintptr_t)cpu_buf + sizeof (struct t_buf)); /* throw away stale trace records */ tbuf.meta[i]->cons = tbuf.meta[i]->prod; } return (0); } static void xdt_detach_trace_buffers(void) { size_t len = tbuf.size * tbuf.cnt; ASSERT(tbuf.va != NULL); hat_unload(kas.a_hat, tbuf.va, len, HAT_UNLOAD_UNMAP | HAT_UNLOAD_UNLOCK); vmem_free(heap_arena, tbuf.va, len); kmem_free(tbuf.meta, tbuf.cnt * sizeof (*tbuf.meta)); kmem_free(tbuf.data, tbuf.cnt * sizeof (*tbuf.data)); } static inline void xdt_process_rec(uint_t cpuid, struct t_rec *rec) { xdt_schedinfo_t *sp = &xdt_cpu_schedinfo[cpuid]; int eid; ASSERT(rec != NULL); ASSERT(xdt_ncpus == xen_get_nphyscpus()); if (cpuid >= xdt_ncpus) { tbuf.stat_spurious_cpu++; return; } switch (rec->event) { /* * Sched probes */ case TRC_SCHED_SWITCH_INFPREV: /* * Info on vCPU being de-scheduled * * rec->data[0] = prev domid * rec->data[1] = time spent on pcpu */ sp->prev_domid = rec->data[0]; sp->prev_ctime = rec->data[1]; break; case TRC_SCHED_SWITCH_INFNEXT: /* * Info on next vCPU to be scheduled * * rec->data[0] = next domid * rec->data[1] = time spent waiting to get on cpu * rec->data[2] = time slice */ sp->next_domid = rec->data[0]; sp->next_wtime = rec->data[1]; sp->next_ts = rec->data[2]; break; case TRC_SCHED_SWITCH: /* * vCPU switch * * rec->data[0] = prev domid * rec->data[1] = prev vcpuid * rec->data[2] = next domid * rec->data[3] = next vcpuid */ if (rec->data[0] != sp->prev_domid && rec->data[2] != sp->next_domid) { /* prev and next info don't match doms being sched'd */ tbuf.stat_spurious_switch++; return; } sp->prev_vcpuid = rec->data[1]; sp->next_vcpuid = rec->data[3]; XDT_PROBE3(IS_IDLE_DOM(sp->prev_domid)? XDT_SCHED_IDLE_OFF_CPU:XDT_SCHED_OFF_CPU, cpuid, sp->prev_domid, sp->prev_vcpuid, sp->prev_ctime); XDT_PROBE4(IS_IDLE_DOM(sp->next_domid)? XDT_SCHED_IDLE_ON_CPU:XDT_SCHED_ON_CPU, cpuid, sp->next_domid, sp->next_vcpuid, sp->next_wtime, sp->next_ts); break; case TRC_SCHED_BLOCK: /* * vCPU blocked * * rec->data[0] = domid * rec->data[1] = vcpuid */ XDT_PROBE2(XDT_SCHED_BLOCK, cpuid, rec->data[0], rec->data[1]); break; case TRC_SCHED_SLEEP: /* * Put vCPU to sleep * * rec->data[0] = domid * rec->data[1] = vcpuid */ XDT_PROBE2(XDT_SCHED_SLEEP, cpuid, rec->data[0], rec->data[1]); break; case TRC_SCHED_WAKE: /* * Wake up vCPU * * rec->data[0] = domid * rec->data[1] = vcpuid */ XDT_PROBE2(XDT_SCHED_WAKE, cpuid, rec->data[0], rec->data[1]); break; case TRC_SCHED_YIELD: /* * vCPU yielded * * rec->data[0] = domid * rec->data[1] = vcpuid */ XDT_PROBE2(XDT_SCHED_YIELD, cpuid, rec->data[0], rec->data[1]); break; case TRC_SCHED_SHUTDOWN: /* * Guest shutting down * * rec->data[0] = domid * rec->data[1] = initiating vcpu * rec->data[2] = shutdown code */ switch (rec->data[2]) { case SHUTDOWN_poweroff: eid = XDT_SCHED_SHUTDOWN_POWEROFF; break; case SHUTDOWN_reboot: eid = XDT_SCHED_SHUTDOWN_REBOOT; break; case SHUTDOWN_suspend: eid = XDT_SCHED_SHUTDOWN_SUSPEND; break; case SHUTDOWN_crash: eid = XDT_SCHED_SHUTDOWN_CRASH; break; default: tbuf.stat_unknown_shutdown++; return; } XDT_PROBE1(eid, cpuid, rec->data[0]); break; /* * Mem probes */ case TRC_MEM_PAGE_GRANT_MAP: /* * Guest mapped page grant * * rec->data[0] = domid */ XDT_PROBE1(XDT_MEM_PAGE_GRANT_MAP, cpuid, rec->data[0]); break; case TRC_MEM_PAGE_GRANT_UNMAP: /* * Guest unmapped page grant * * rec->data[0] = domid */ XDT_PROBE1(XDT_MEM_PAGE_GRANT_UNMAP, cpuid, rec->data[0]); break; case TRC_MEM_PAGE_GRANT_TRANSFER: /* * Page grant is being transferred * * rec->data[0] = target domid */ XDT_PROBE1(XDT_MEM_PAGE_GRANT_TRANSFER, cpuid, rec->data[0]); break; /* * HVM probes */ case TRC_HVM_VMENTRY: /* * Return to guest via vmx_launch/vmrun * * rec->data[0] = (domid<<16 + vcpuid) */ XDT_PROBE2(XDT_HVM_VMENTRY, cpuid, HVM_DOMID(rec->data[0]), HVM_VCPUID(rec->data[0])); break; case TRC_HVM_VMEXIT: /* * Entry into VMEXIT handler * * rec->data[0] = (domid<<16 + vcpuid) * rec->data[1] = guest rip * rec->data[2] = cpu vendor specific exit code */ XDT_PROBE4(XDT_HVM_VMEXIT, cpuid, HVM_DOMID(rec->data[0]), HVM_VCPUID(rec->data[0]), rec->data[1], rec->data[2]); break; case TRC_LOST_RECORDS: tbuf.stat_dropped_recs++; break; default: tbuf.stat_unknown_recs++; break; } } /*ARGSUSED*/ static void xdt_tbuf_scan(void *arg) { uint_t cpuid; size_t nrecs; struct t_rec *rec; uint32_t prod; nrecs = (tbuf.size - sizeof (struct t_buf)) / sizeof (struct t_rec); /* scan all cpu buffers for new records */ for (cpuid = 0; cpuid < tbuf.cnt; cpuid++) { prod = tbuf.meta[cpuid]->prod; membar_consumer(); /* read prod /then/ data */ while (tbuf.meta[cpuid]->cons != prod) { rec = tbuf.data[cpuid] + tbuf.meta[cpuid]->cons % nrecs; xdt_process_rec(cpuid, rec); membar_exit(); /* read data /then/ update cons */ tbuf.meta[cpuid]->cons++; } } } static void xdt_cyclic_enable(void) { cyc_handler_t hdlr; cyc_time_t when; ASSERT(MUTEX_HELD(&cpu_lock)); hdlr.cyh_func = xdt_tbuf_scan; hdlr.cyh_arg = NULL; hdlr.cyh_level = CY_LOW_LEVEL; when.cyt_interval = xdt_poll_nsec; when.cyt_when = dtrace_gethrtime() + when.cyt_interval; xdt_cyclic = cyclic_add(&hdlr, &when); } static void xdt_probe_create(xdt_probe_t *p) { ASSERT(p != NULL && p->pr_mod != NULL); if (dtrace_probe_lookup(xdt_id, p->pr_mod, NULL, p->pr_name) != 0) return; xdt_prid[p->evt_id] = dtrace_probe_create(xdt_id, p->pr_mod, NULL, p->pr_name, dtrace_mach_aframes(), p); } /*ARGSUSED*/ static void xdt_provide(void *arg, const dtrace_probedesc_t *desc) { const char *mod, *name; int i; if (desc == NULL) { for (i = 0; xdt_probe[i].pr_mod != NULL; i++) { xdt_probe_create(&xdt_probe[i]); } } else { mod = desc->dtpd_mod; name = desc->dtpd_name; for (i = 0; xdt_probe[i].pr_mod != NULL; i++) { int l1 = strlen(xdt_probe[i].pr_name); int l2 = strlen(xdt_probe[i].pr_mod); if (strncmp(name, xdt_probe[i].pr_name, l1) == 0 && strncmp(mod, xdt_probe[i].pr_mod, l2) == 0) break; } if (xdt_probe[i].pr_mod == NULL) return; xdt_probe_create(&xdt_probe[i]); } } /*ARGSUSED*/ static void xdt_destroy(void *arg, dtrace_id_t id, void *parg) { xdt_probe_t *p = parg; xdt_prid[p->evt_id] = 0; } static void xdt_set_trace_mask(uint32_t mask) { xen_sysctl_tbuf_op_t tbuf_op; tbuf_op.cmd = XEN_SYSCTL_TBUFOP_set_evt_mask; tbuf_op.evt_mask = mask; (void) xdt_sysctl_tbuf(&tbuf_op); } /*ARGSUSED*/ static void xdt_enable(void *arg, dtrace_id_t id, void *parg) { xdt_probe_t *p = parg; xen_sysctl_tbuf_op_t tbuf_op; ASSERT(MUTEX_HELD(&cpu_lock)); ASSERT(xdt_prid[p->evt_id] != 0); xdt_probemap[p->evt_id] = xdt_prid[p->evt_id]; xdt_classinfo[p->class].cnt++; if (xdt_classinfo[p->class].cnt == 1) { /* set the trace mask for this class */ cur_trace_mask |= xdt_classinfo[p->class].trc_mask; xdt_set_trace_mask(cur_trace_mask); } if (xdt_cyclic == CYCLIC_NONE) { /* * DTrace doesn't have the notion of failing an enabling. It * works on the premise that, if you have advertised a probe * via the pops->dtps_provide() function, you can enable it. * Failure is not an option. In the case where we can't enable * Xen tracing the consumer will carry on regardless and * think all is OK except the probes will never fire. */ tbuf_op.cmd = XEN_SYSCTL_TBUFOP_enable; if (xdt_sysctl_tbuf(&tbuf_op) != 0) { cmn_err(CE_NOTE, "Couldn't enable hypervisor tracing."); return; } xdt_cyclic_enable(); } } /*ARGSUSED*/ static void xdt_disable(void *arg, dtrace_id_t id, void *parg) { xdt_probe_t *p = parg; xen_sysctl_tbuf_op_t tbuf_op; int i, err; ASSERT(MUTEX_HELD(&cpu_lock)); ASSERT(xdt_probemap[p->evt_id] != 0); ASSERT(xdt_probemap[p->evt_id] == xdt_prid[p->evt_id]); ASSERT(xdt_classinfo[p->class].cnt > 0); /* * We could be here in the slight window between the cyclic firing and * a call to dtrace_probe() occurring. We need to be careful if we tear * down any shared state. */ xdt_probemap[p->evt_id] = 0; xdt_classinfo[p->class].cnt--; if (xdt_nr_active_probes() == 0) { cur_trace_mask = 0; if (xdt_cyclic == CYCLIC_NONE) return; /* * We will try to disable the trace buffers. If we fail for some * reason we will try again, up to a count of XDT_TBUF_RETRY. * If we still aren't successful we try to set the trace mask * to 0 in order to prevent trace records from being written. */ tbuf_op.cmd = XEN_SYSCTL_TBUFOP_disable; i = 0; do { err = xdt_sysctl_tbuf(&tbuf_op); } while ((err != 0) && (++i < XDT_TBUF_RETRY)); if (err != 0) { cmn_err(CE_NOTE, "Couldn't disable hypervisor tracing."); xdt_set_trace_mask(0); } else { cyclic_remove(xdt_cyclic); xdt_cyclic = CYCLIC_NONE; /* * We don't bother making the hypercall to set * the trace mask, since it will be reset when * tracing is re-enabled. */ } } else if (xdt_classinfo[p->class].cnt == 0) { cur_trace_mask ^= xdt_classinfo[p->class].trc_mask; /* other probes are enabled, so add the sub-class mask back */ cur_trace_mask |= 0xF000; xdt_set_trace_mask(cur_trace_mask); } } static dtrace_pattr_t xdt_attr = { { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_PLATFORM }, { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_PLATFORM }, { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN }, { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_PLATFORM }, { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_PLATFORM }, }; static dtrace_pops_t xdt_pops = { xdt_provide, /* dtps_provide() */ NULL, /* dtps_provide_module() */ xdt_enable, /* dtps_enable() */ xdt_disable, /* dtps_disable() */ NULL, /* dtps_suspend() */ NULL, /* dtps_resume() */ NULL, /* dtps_getargdesc() */ NULL, /* dtps_getargval() */ NULL, /* dtps_usermode() */ xdt_destroy /* dtps_destroy() */ }; static int xdt_attach(dev_info_t *devi, ddi_attach_cmd_t cmd) { int val; if (!DOMAIN_IS_INITDOMAIN(xen_info)) return (DDI_FAILURE); switch (cmd) { case DDI_ATTACH: break; case DDI_RESUME: /* * We might support proper suspend/resume in the future, so, * return DDI_FAILURE for now. */ return (DDI_FAILURE); default: return (DDI_FAILURE); } xdt_ncpus = xen_get_nphyscpus(); ASSERT(xdt_ncpus > 0); if (ddi_create_minor_node(devi, "xdt", S_IFCHR, 0, DDI_PSEUDO, 0) == DDI_FAILURE || xdt_attach_trace_buffers() != 0 || dtrace_register("xdt", &xdt_attr, DTRACE_PRIV_KERNEL, NULL, &xdt_pops, NULL, &xdt_id) != 0) { if (tbuf.va != NULL) xdt_detach_trace_buffers(); ddi_remove_minor_node(devi, NULL); return (DDI_FAILURE); } val = ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS, "xdt_poll_nsec", XDT_POLL_DEFAULT); xdt_poll_nsec = MAX(val, XDT_POLL_MIN); xdt_cpu_schedinfo = (xdt_schedinfo_t *)kmem_alloc(xdt_ncpus * sizeof (xdt_schedinfo_t), KM_SLEEP); xdt_init_trace_masks(); xdt_kstat_init(); xdt_devi = devi; ddi_report_dev(devi); return (DDI_SUCCESS); } static int xdt_detach(dev_info_t *devi, ddi_detach_cmd_t cmd) { switch (cmd) { case DDI_DETACH: break; case DDI_SUSPEND: /* * We might support proper suspend/resume in the future. So * return DDI_FAILURE for now. */ return (DDI_FAILURE); default: return (DDI_FAILURE); } if (dtrace_unregister(xdt_id) != 0) return (DDI_FAILURE); xdt_detach_trace_buffers(); kmem_free(xdt_cpu_schedinfo, xdt_ncpus * sizeof (xdt_schedinfo_t)); if (xdt_cyclic != CYCLIC_NONE) cyclic_remove(xdt_cyclic); if (xdt_kstats != NULL) kstat_delete(xdt_kstats); xdt_devi = (void *)0; ddi_remove_minor_node(devi, NULL); return (DDI_SUCCESS); } /*ARGSUSED*/ static int xdt_info(dev_info_t *devi, ddi_info_cmd_t infocmd, void *arg, void **result) { int error; switch (infocmd) { case DDI_INFO_DEVT2DEVINFO: *result = xdt_devi; error = DDI_SUCCESS; break; case DDI_INFO_DEVT2INSTANCE: *result = (void *)0; error = DDI_SUCCESS; break; default: error = DDI_FAILURE; } return (error); } static struct cb_ops xdt_cb_ops = { nulldev, /* open(9E) */ nodev, /* close(9E) */ nodev, /* strategy(9E) */ nodev, /* print(9E) */ nodev, /* dump(9E) */ nodev, /* read(9E) */ nodev, /* write(9E) */ nodev, /* ioctl(9E) */ nodev, /* devmap(9E) */ nodev, /* mmap(9E) */ nodev, /* segmap(9E) */ nochpoll, /* chpoll(9E) */ ddi_prop_op, /* prop_op(9E) */ NULL, /* streamtab(9S) */ D_MP | D_64BIT | D_NEW /* cb_flag */ }; static struct dev_ops xdt_ops = { DEVO_REV, /* devo_rev */ 0, /* devo_refcnt */ xdt_info, /* getinfo(9E) */ nulldev, /* identify(9E) */ nulldev, /* probe(9E) */ xdt_attach, /* attach(9E) */ xdt_detach, /* detach(9E) */ nulldev, /* devo_reset */ &xdt_cb_ops, /* devo_cb_ops */ NULL, /* devo_bus_ops */ NULL /* power(9E) */ }; static struct modldrv modldrv = { &mod_driverops, "Hypervisor event tracing", &xdt_ops }; static struct modlinkage modlinkage = { MODREV_1, &modldrv, NULL }; int _init(void) { return (mod_install(&modlinkage)); } int _fini(void) { return (mod_remove(&modlinkage)); } int _info(struct modinfo *modinfop) { return (mod_info(&modlinkage, modinfop)); }