xref: /openbmc/qemu/target/riscv/pmu.c (revision 29318db1)
1 /*
2  * RISC-V PMU file.
3  *
4  * Copyright (c) 2021 Western Digital Corporation or its affiliates.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2 or later, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License along with
16  * this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include "qemu/osdep.h"
20 #include "qemu/log.h"
21 #include "qemu/error-report.h"
22 #include "qemu/timer.h"
23 #include "cpu.h"
24 #include "pmu.h"
25 #include "sysemu/cpu-timers.h"
26 #include "sysemu/device_tree.h"
27 
28 #define RISCV_TIMEBASE_FREQ 1000000000 /* 1Ghz */
29 
30 /*
31  * To keep it simple, any event can be mapped to any programmable counters in
32  * QEMU. The generic cycle & instruction count events can also be monitored
33  * using programmable counters. In that case, mcycle & minstret must continue
34  * to provide the correct value as well. Heterogeneous PMU per hart is not
35  * supported yet. Thus, number of counters are same across all harts.
36  */
37 void riscv_pmu_generate_fdt_node(void *fdt, uint32_t cmask, char *pmu_name)
38 {
39     uint32_t fdt_event_ctr_map[15] = {};
40 
41    /*
42     * The event encoding is specified in the SBI specification
43     * Event idx is a 20bits wide number encoded as follows:
44     * event_idx[19:16] = type
45     * event_idx[15:0] = code
46     * The code field in cache events are encoded as follows:
47     * event_idx.code[15:3] = cache_id
48     * event_idx.code[2:1] = op_id
49     * event_idx.code[0:0] = result_id
50     */
51 
52    /* SBI_PMU_HW_CPU_CYCLES: 0x01 : type(0x00) */
53    fdt_event_ctr_map[0] = cpu_to_be32(0x00000001);
54    fdt_event_ctr_map[1] = cpu_to_be32(0x00000001);
55    fdt_event_ctr_map[2] = cpu_to_be32(cmask | 1 << 0);
56 
57    /* SBI_PMU_HW_INSTRUCTIONS: 0x02 : type(0x00) */
58    fdt_event_ctr_map[3] = cpu_to_be32(0x00000002);
59    fdt_event_ctr_map[4] = cpu_to_be32(0x00000002);
60    fdt_event_ctr_map[5] = cpu_to_be32(cmask | 1 << 2);
61 
62    /* SBI_PMU_HW_CACHE_DTLB : 0x03 READ : 0x00 MISS : 0x00 type(0x01) */
63    fdt_event_ctr_map[6] = cpu_to_be32(0x00010019);
64    fdt_event_ctr_map[7] = cpu_to_be32(0x00010019);
65    fdt_event_ctr_map[8] = cpu_to_be32(cmask);
66 
67    /* SBI_PMU_HW_CACHE_DTLB : 0x03 WRITE : 0x01 MISS : 0x00 type(0x01) */
68    fdt_event_ctr_map[9] = cpu_to_be32(0x0001001B);
69    fdt_event_ctr_map[10] = cpu_to_be32(0x0001001B);
70    fdt_event_ctr_map[11] = cpu_to_be32(cmask);
71 
72    /* SBI_PMU_HW_CACHE_ITLB : 0x04 READ : 0x00 MISS : 0x00 type(0x01) */
73    fdt_event_ctr_map[12] = cpu_to_be32(0x00010021);
74    fdt_event_ctr_map[13] = cpu_to_be32(0x00010021);
75    fdt_event_ctr_map[14] = cpu_to_be32(cmask);
76 
77    /* This a OpenSBI specific DT property documented in OpenSBI docs */
78    qemu_fdt_setprop(fdt, pmu_name, "riscv,event-to-mhpmcounters",
79                     fdt_event_ctr_map, sizeof(fdt_event_ctr_map));
80 }
81 
82 static bool riscv_pmu_counter_valid(RISCVCPU *cpu, uint32_t ctr_idx)
83 {
84     if (ctr_idx < 3 || ctr_idx >= RV_MAX_MHPMCOUNTERS ||
85         !(cpu->pmu_avail_ctrs & BIT(ctr_idx))) {
86         return false;
87     } else {
88         return true;
89     }
90 }
91 
92 static bool riscv_pmu_counter_enabled(RISCVCPU *cpu, uint32_t ctr_idx)
93 {
94     CPURISCVState *env = &cpu->env;
95 
96     if (riscv_pmu_counter_valid(cpu, ctr_idx) &&
97         !get_field(env->mcountinhibit, BIT(ctr_idx))) {
98         return true;
99     } else {
100         return false;
101     }
102 }
103 
104 static int riscv_pmu_incr_ctr_rv32(RISCVCPU *cpu, uint32_t ctr_idx)
105 {
106     CPURISCVState *env = &cpu->env;
107     target_ulong max_val = UINT32_MAX;
108     PMUCTRState *counter = &env->pmu_ctrs[ctr_idx];
109     bool virt_on = env->virt_enabled;
110 
111     /* Privilege mode filtering */
112     if ((env->priv == PRV_M &&
113         (env->mhpmeventh_val[ctr_idx] & MHPMEVENTH_BIT_MINH)) ||
114         (env->priv == PRV_S && virt_on &&
115         (env->mhpmeventh_val[ctr_idx] & MHPMEVENTH_BIT_VSINH)) ||
116         (env->priv == PRV_U && virt_on &&
117         (env->mhpmeventh_val[ctr_idx] & MHPMEVENTH_BIT_VUINH)) ||
118         (env->priv == PRV_S && !virt_on &&
119         (env->mhpmeventh_val[ctr_idx] & MHPMEVENTH_BIT_SINH)) ||
120         (env->priv == PRV_U && !virt_on &&
121         (env->mhpmeventh_val[ctr_idx] & MHPMEVENTH_BIT_UINH))) {
122         return 0;
123     }
124 
125     /* Handle the overflow scenario */
126     if (counter->mhpmcounter_val == max_val) {
127         if (counter->mhpmcounterh_val == max_val) {
128             counter->mhpmcounter_val = 0;
129             counter->mhpmcounterh_val = 0;
130             /* Generate interrupt only if OF bit is clear */
131             if (!(env->mhpmeventh_val[ctr_idx] & MHPMEVENTH_BIT_OF)) {
132                 env->mhpmeventh_val[ctr_idx] |= MHPMEVENTH_BIT_OF;
133                 riscv_cpu_update_mip(env, MIP_LCOFIP, BOOL_TO_MASK(1));
134             }
135         } else {
136             counter->mhpmcounterh_val++;
137         }
138     } else {
139         counter->mhpmcounter_val++;
140     }
141 
142     return 0;
143 }
144 
145 static int riscv_pmu_incr_ctr_rv64(RISCVCPU *cpu, uint32_t ctr_idx)
146 {
147     CPURISCVState *env = &cpu->env;
148     PMUCTRState *counter = &env->pmu_ctrs[ctr_idx];
149     uint64_t max_val = UINT64_MAX;
150     bool virt_on = env->virt_enabled;
151 
152     /* Privilege mode filtering */
153     if ((env->priv == PRV_M &&
154         (env->mhpmevent_val[ctr_idx] & MHPMEVENT_BIT_MINH)) ||
155         (env->priv == PRV_S && virt_on &&
156         (env->mhpmevent_val[ctr_idx] & MHPMEVENT_BIT_VSINH)) ||
157         (env->priv == PRV_U && virt_on &&
158         (env->mhpmevent_val[ctr_idx] & MHPMEVENT_BIT_VUINH)) ||
159         (env->priv == PRV_S && !virt_on &&
160         (env->mhpmevent_val[ctr_idx] & MHPMEVENT_BIT_SINH)) ||
161         (env->priv == PRV_U && !virt_on &&
162         (env->mhpmevent_val[ctr_idx] & MHPMEVENT_BIT_UINH))) {
163         return 0;
164     }
165 
166     /* Handle the overflow scenario */
167     if (counter->mhpmcounter_val == max_val) {
168         counter->mhpmcounter_val = 0;
169         /* Generate interrupt only if OF bit is clear */
170         if (!(env->mhpmevent_val[ctr_idx] & MHPMEVENT_BIT_OF)) {
171             env->mhpmevent_val[ctr_idx] |= MHPMEVENT_BIT_OF;
172             riscv_cpu_update_mip(env, MIP_LCOFIP, BOOL_TO_MASK(1));
173         }
174     } else {
175         counter->mhpmcounter_val++;
176     }
177     return 0;
178 }
179 
180 /*
181  * Information needed to update counters:
182  *  new_priv, new_virt: To correctly save starting snapshot for the newly
183  *                      started mode. Look at array being indexed with newprv.
184  *  old_priv, old_virt: To correctly select previous snapshot for old priv
185  *                      and compute delta. Also to select correct counter
186  *                      to inc. Look at arrays being indexed with env->priv.
187  *
188  *  To avoid the complexity of calling this function, we assume that
189  *  env->priv and env->virt_enabled contain old priv and old virt and
190  *  new priv and new virt values are passed in as arguments.
191  */
192 static void riscv_pmu_icount_update_priv(CPURISCVState *env,
193                                          target_ulong newpriv, bool new_virt)
194 {
195     uint64_t *snapshot_prev, *snapshot_new;
196     uint64_t current_icount;
197     uint64_t *counter_arr;
198     uint64_t delta;
199 
200     if (icount_enabled()) {
201         current_icount = icount_get_raw();
202     } else {
203         current_icount = cpu_get_host_ticks();
204     }
205 
206     if (env->virt_enabled) {
207         counter_arr = env->pmu_fixed_ctrs[1].counter_virt;
208         snapshot_prev = env->pmu_fixed_ctrs[1].counter_virt_prev;
209     } else {
210         counter_arr = env->pmu_fixed_ctrs[1].counter;
211         snapshot_prev = env->pmu_fixed_ctrs[1].counter_prev;
212     }
213 
214     if (new_virt) {
215         snapshot_new = env->pmu_fixed_ctrs[1].counter_virt_prev;
216     } else {
217         snapshot_new = env->pmu_fixed_ctrs[1].counter_prev;
218     }
219 
220      /*
221       * new_priv can be same as env->priv. So we need to calculate
222       * delta first before updating snapshot_new[new_priv].
223       */
224     delta = current_icount - snapshot_prev[env->priv];
225     snapshot_new[newpriv] = current_icount;
226 
227     counter_arr[env->priv] += delta;
228 }
229 
230 static void riscv_pmu_cycle_update_priv(CPURISCVState *env,
231                                         target_ulong newpriv, bool new_virt)
232 {
233     uint64_t *snapshot_prev, *snapshot_new;
234     uint64_t current_ticks;
235     uint64_t *counter_arr;
236     uint64_t delta;
237 
238     if (icount_enabled()) {
239         current_ticks = icount_get();
240     } else {
241         current_ticks = cpu_get_host_ticks();
242     }
243 
244     if (env->virt_enabled) {
245         counter_arr = env->pmu_fixed_ctrs[0].counter_virt;
246         snapshot_prev = env->pmu_fixed_ctrs[0].counter_virt_prev;
247     } else {
248         counter_arr = env->pmu_fixed_ctrs[0].counter;
249         snapshot_prev = env->pmu_fixed_ctrs[0].counter_prev;
250     }
251 
252     if (new_virt) {
253         snapshot_new = env->pmu_fixed_ctrs[0].counter_virt_prev;
254     } else {
255         snapshot_new = env->pmu_fixed_ctrs[0].counter_prev;
256     }
257 
258     delta = current_ticks - snapshot_prev[env->priv];
259     snapshot_new[newpriv] = current_ticks;
260 
261     counter_arr[env->priv] += delta;
262 }
263 
264 void riscv_pmu_update_fixed_ctrs(CPURISCVState *env, target_ulong newpriv,
265                                  bool new_virt)
266 {
267     riscv_pmu_cycle_update_priv(env, newpriv, new_virt);
268     riscv_pmu_icount_update_priv(env, newpriv, new_virt);
269 }
270 
271 int riscv_pmu_incr_ctr(RISCVCPU *cpu, enum riscv_pmu_event_idx event_idx)
272 {
273     uint32_t ctr_idx;
274     int ret;
275     CPURISCVState *env = &cpu->env;
276     gpointer value;
277 
278     if (!cpu->cfg.pmu_mask) {
279         return 0;
280     }
281     value = g_hash_table_lookup(cpu->pmu_event_ctr_map,
282                                 GUINT_TO_POINTER(event_idx));
283     if (!value) {
284         return -1;
285     }
286 
287     ctr_idx = GPOINTER_TO_UINT(value);
288     if (!riscv_pmu_counter_enabled(cpu, ctr_idx)) {
289         return -1;
290     }
291 
292     if (riscv_cpu_mxl(env) == MXL_RV32) {
293         ret = riscv_pmu_incr_ctr_rv32(cpu, ctr_idx);
294     } else {
295         ret = riscv_pmu_incr_ctr_rv64(cpu, ctr_idx);
296     }
297 
298     return ret;
299 }
300 
301 bool riscv_pmu_ctr_monitor_instructions(CPURISCVState *env,
302                                         uint32_t target_ctr)
303 {
304     RISCVCPU *cpu;
305     uint32_t event_idx;
306     uint32_t ctr_idx;
307 
308     /* Fixed instret counter */
309     if (target_ctr == 2) {
310         return true;
311     }
312 
313     cpu = env_archcpu(env);
314     if (!cpu->pmu_event_ctr_map) {
315         return false;
316     }
317 
318     event_idx = RISCV_PMU_EVENT_HW_INSTRUCTIONS;
319     ctr_idx = GPOINTER_TO_UINT(g_hash_table_lookup(cpu->pmu_event_ctr_map,
320                                GUINT_TO_POINTER(event_idx)));
321     if (!ctr_idx) {
322         return false;
323     }
324 
325     return target_ctr == ctr_idx ? true : false;
326 }
327 
328 bool riscv_pmu_ctr_monitor_cycles(CPURISCVState *env, uint32_t target_ctr)
329 {
330     RISCVCPU *cpu;
331     uint32_t event_idx;
332     uint32_t ctr_idx;
333 
334     /* Fixed mcycle counter */
335     if (target_ctr == 0) {
336         return true;
337     }
338 
339     cpu = env_archcpu(env);
340     if (!cpu->pmu_event_ctr_map) {
341         return false;
342     }
343 
344     event_idx = RISCV_PMU_EVENT_HW_CPU_CYCLES;
345     ctr_idx = GPOINTER_TO_UINT(g_hash_table_lookup(cpu->pmu_event_ctr_map,
346                                GUINT_TO_POINTER(event_idx)));
347 
348     /* Counter zero is not used for event_ctr_map */
349     if (!ctr_idx) {
350         return false;
351     }
352 
353     return (target_ctr == ctr_idx) ? true : false;
354 }
355 
356 static gboolean pmu_remove_event_map(gpointer key, gpointer value,
357                                      gpointer udata)
358 {
359     return (GPOINTER_TO_UINT(value) == GPOINTER_TO_UINT(udata)) ? true : false;
360 }
361 
362 static int64_t pmu_icount_ticks_to_ns(int64_t value)
363 {
364     int64_t ret = 0;
365 
366     if (icount_enabled()) {
367         ret = icount_to_ns(value);
368     } else {
369         ret = (NANOSECONDS_PER_SECOND / RISCV_TIMEBASE_FREQ) * value;
370     }
371 
372     return ret;
373 }
374 
375 int riscv_pmu_update_event_map(CPURISCVState *env, uint64_t value,
376                                uint32_t ctr_idx)
377 {
378     uint32_t event_idx;
379     RISCVCPU *cpu = env_archcpu(env);
380 
381     if (!riscv_pmu_counter_valid(cpu, ctr_idx) || !cpu->pmu_event_ctr_map) {
382         return -1;
383     }
384 
385     /*
386      * Expected mhpmevent value is zero for reset case. Remove the current
387      * mapping.
388      */
389     if (!value) {
390         g_hash_table_foreach_remove(cpu->pmu_event_ctr_map,
391                                     pmu_remove_event_map,
392                                     GUINT_TO_POINTER(ctr_idx));
393         return 0;
394     }
395 
396     event_idx = value & MHPMEVENT_IDX_MASK;
397     if (g_hash_table_lookup(cpu->pmu_event_ctr_map,
398                             GUINT_TO_POINTER(event_idx))) {
399         return 0;
400     }
401 
402     switch (event_idx) {
403     case RISCV_PMU_EVENT_HW_CPU_CYCLES:
404     case RISCV_PMU_EVENT_HW_INSTRUCTIONS:
405     case RISCV_PMU_EVENT_CACHE_DTLB_READ_MISS:
406     case RISCV_PMU_EVENT_CACHE_DTLB_WRITE_MISS:
407     case RISCV_PMU_EVENT_CACHE_ITLB_PREFETCH_MISS:
408         break;
409     default:
410         /* We don't support any raw events right now */
411         return -1;
412     }
413     g_hash_table_insert(cpu->pmu_event_ctr_map, GUINT_TO_POINTER(event_idx),
414                         GUINT_TO_POINTER(ctr_idx));
415 
416     return 0;
417 }
418 
419 static bool pmu_hpmevent_is_of_set(CPURISCVState *env, uint32_t ctr_idx)
420 {
421     target_ulong mhpmevent_val;
422     uint64_t of_bit_mask;
423 
424     if (riscv_cpu_mxl(env) == MXL_RV32) {
425         mhpmevent_val = env->mhpmeventh_val[ctr_idx];
426         of_bit_mask = MHPMEVENTH_BIT_OF;
427      } else {
428         mhpmevent_val = env->mhpmevent_val[ctr_idx];
429         of_bit_mask = MHPMEVENT_BIT_OF;
430     }
431 
432     return get_field(mhpmevent_val, of_bit_mask);
433 }
434 
435 static bool pmu_hpmevent_set_of_if_clear(CPURISCVState *env, uint32_t ctr_idx)
436 {
437     target_ulong *mhpmevent_val;
438     uint64_t of_bit_mask;
439 
440     if (riscv_cpu_mxl(env) == MXL_RV32) {
441         mhpmevent_val = &env->mhpmeventh_val[ctr_idx];
442         of_bit_mask = MHPMEVENTH_BIT_OF;
443      } else {
444         mhpmevent_val = &env->mhpmevent_val[ctr_idx];
445         of_bit_mask = MHPMEVENT_BIT_OF;
446     }
447 
448     if (!get_field(*mhpmevent_val, of_bit_mask)) {
449         *mhpmevent_val |= of_bit_mask;
450         return true;
451     }
452 
453     return false;
454 }
455 
456 static void pmu_timer_trigger_irq(RISCVCPU *cpu,
457                                   enum riscv_pmu_event_idx evt_idx)
458 {
459     uint32_t ctr_idx;
460     CPURISCVState *env = &cpu->env;
461     PMUCTRState *counter;
462     int64_t irq_trigger_at;
463     uint64_t curr_ctr_val, curr_ctrh_val;
464     uint64_t ctr_val;
465 
466     if (evt_idx != RISCV_PMU_EVENT_HW_CPU_CYCLES &&
467         evt_idx != RISCV_PMU_EVENT_HW_INSTRUCTIONS) {
468         return;
469     }
470 
471     ctr_idx = GPOINTER_TO_UINT(g_hash_table_lookup(cpu->pmu_event_ctr_map,
472                                GUINT_TO_POINTER(evt_idx)));
473     if (!riscv_pmu_counter_enabled(cpu, ctr_idx)) {
474         return;
475     }
476 
477     /* Generate interrupt only if OF bit is clear */
478     if (pmu_hpmevent_is_of_set(env, ctr_idx)) {
479         return;
480     }
481 
482     counter = &env->pmu_ctrs[ctr_idx];
483     if (counter->irq_overflow_left > 0) {
484         irq_trigger_at = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
485                         counter->irq_overflow_left;
486         timer_mod_anticipate_ns(cpu->pmu_timer, irq_trigger_at);
487         counter->irq_overflow_left = 0;
488         return;
489     }
490 
491     riscv_pmu_read_ctr(env, (target_ulong *)&curr_ctr_val, false, ctr_idx);
492     ctr_val = counter->mhpmcounter_val;
493     if (riscv_cpu_mxl(env) == MXL_RV32) {
494         riscv_pmu_read_ctr(env, (target_ulong *)&curr_ctrh_val, true, ctr_idx);
495         curr_ctr_val = curr_ctr_val | (curr_ctrh_val << 32);
496         ctr_val = ctr_val |
497                 ((uint64_t)counter->mhpmcounterh_val << 32);
498     }
499 
500     /*
501      * We can not accommodate for inhibited modes when setting up timer. Check
502      * if the counter has actually overflowed or not by comparing current
503      * counter value (accommodated for inhibited modes) with software written
504      * counter value.
505      */
506     if (curr_ctr_val >= ctr_val) {
507         riscv_pmu_setup_timer(env, curr_ctr_val, ctr_idx);
508         return;
509     }
510 
511     if (cpu->pmu_avail_ctrs & BIT(ctr_idx)) {
512         if (pmu_hpmevent_set_of_if_clear(env, ctr_idx)) {
513             riscv_cpu_update_mip(env, MIP_LCOFIP, BOOL_TO_MASK(1));
514         }
515     }
516 }
517 
518 /* Timer callback for instret and cycle counter overflow */
519 void riscv_pmu_timer_cb(void *priv)
520 {
521     RISCVCPU *cpu = priv;
522 
523     /* Timer event was triggered only for these events */
524     pmu_timer_trigger_irq(cpu, RISCV_PMU_EVENT_HW_CPU_CYCLES);
525     pmu_timer_trigger_irq(cpu, RISCV_PMU_EVENT_HW_INSTRUCTIONS);
526 }
527 
528 int riscv_pmu_setup_timer(CPURISCVState *env, uint64_t value, uint32_t ctr_idx)
529 {
530     uint64_t overflow_delta, overflow_at, curr_ns;
531     int64_t overflow_ns, overflow_left = 0;
532     RISCVCPU *cpu = env_archcpu(env);
533     PMUCTRState *counter = &env->pmu_ctrs[ctr_idx];
534 
535     /* No need to setup a timer if LCOFI is disabled when OF is set */
536     if (!riscv_pmu_counter_valid(cpu, ctr_idx) || !cpu->cfg.ext_sscofpmf ||
537         pmu_hpmevent_is_of_set(env, ctr_idx)) {
538         return -1;
539     }
540 
541     if (value) {
542         overflow_delta = UINT64_MAX - value + 1;
543     } else {
544         overflow_delta = UINT64_MAX;
545     }
546 
547     /*
548      * QEMU supports only int64_t timers while RISC-V counters are uint64_t.
549      * Compute the leftover and save it so that it can be reprogrammed again
550      * when timer expires.
551      */
552     if (overflow_delta > INT64_MAX) {
553         overflow_left = overflow_delta - INT64_MAX;
554     }
555 
556     if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) ||
557         riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) {
558         overflow_ns = pmu_icount_ticks_to_ns((int64_t)overflow_delta);
559         overflow_left = pmu_icount_ticks_to_ns(overflow_left) ;
560     } else {
561         return -1;
562     }
563     curr_ns = (uint64_t)qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
564     overflow_at =  curr_ns + overflow_ns;
565     if (overflow_at <= curr_ns)
566         overflow_at = UINT64_MAX;
567 
568     if (overflow_at > INT64_MAX) {
569         overflow_left += overflow_at - INT64_MAX;
570         counter->irq_overflow_left = overflow_left;
571         overflow_at = INT64_MAX;
572     }
573     timer_mod_anticipate_ns(cpu->pmu_timer, overflow_at);
574 
575     return 0;
576 }
577 
578 
579 void riscv_pmu_init(RISCVCPU *cpu, Error **errp)
580 {
581     if (cpu->cfg.pmu_mask & (COUNTEREN_CY | COUNTEREN_TM | COUNTEREN_IR)) {
582         error_setg(errp, "\"pmu-mask\" contains invalid bits (0-2) set");
583         return;
584     }
585 
586     if (ctpop32(cpu->cfg.pmu_mask) > (RV_MAX_MHPMCOUNTERS - 3)) {
587         error_setg(errp, "Number of counters exceeds maximum available");
588         return;
589     }
590 
591     cpu->pmu_event_ctr_map = g_hash_table_new(g_direct_hash, g_direct_equal);
592     if (!cpu->pmu_event_ctr_map) {
593         error_setg(errp, "Unable to allocate PMU event hash table");
594         return;
595     }
596 
597     cpu->pmu_avail_ctrs = cpu->cfg.pmu_mask;
598 }
599