[linux-block.git] / virt / kvm / arm / pmu.c

/*
 * Copyright (C) 2015 Linaro Ltd.
 * Author: Shannon Zhao <shannon.zhao@linaro.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/cpu.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/perf_event.h>
#include <asm/kvm_emulate.h>
#include <kvm/arm_pmu.h>

/**
 * kvm_pmu_get_counter_value - get PMU counter value
 * @vcpu: The vcpu pointer
 * @select_idx: The counter index
 */
u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
{
	u64 counter, reg, enabled, running;
	struct kvm_pmu *pmu = &vcpu->arch.pmu;
	struct kvm_pmc *pmc = &pmu->pmc[select_idx];

	reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
	      ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
	counter = vcpu_sys_reg(vcpu, reg);

	/* The real counter value is equal to the value of counter register plus
	 * the value perf event counts.
	 */
	if (pmc->perf_event)
		counter += perf_event_read_value(pmc->perf_event, &enabled,
						 &running);

	return counter & pmc->bitmask;
}

/**
 * kvm_pmu_set_counter_value - set PMU counter value
 * @vcpu: The vcpu pointer
 * @select_idx: The counter index
 * @val: The counter value
 */
void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
{
	u64 reg;

	reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
	      ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
	vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx);
}

u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu)
{
	u64 val = vcpu_sys_reg(vcpu, PMCR_EL0) >> ARMV8_PMU_PMCR_N_SHIFT;

	val &= ARMV8_PMU_PMCR_N_MASK;
	if (val == 0)
		return BIT(ARMV8_PMU_CYCLE_IDX);
	else
		return GENMASK(val - 1, 0) | BIT(ARMV8_PMU_CYCLE_IDX);
}

/**
 * kvm_pmu_enable_counter - enable selected PMU counter
 * @vcpu: The vcpu pointer
 * @val: the value guest writes to PMCNTENSET register
 *
 * Call perf_event_enable to start counting the perf event
 */
void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val)
{
	int i;
	struct kvm_pmu *pmu = &vcpu->arch.pmu;
	struct kvm_pmc *pmc;

	if (!(vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E) || !val)
		return;

	for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
		if (!(val & BIT(i)))
			continue;

		pmc = &pmu->pmc[i];
		if (pmc->perf_event) {
			perf_event_enable(pmc->perf_event);
			if (pmc->perf_event->state != PERF_EVENT_STATE_ACTIVE)
				kvm_debug("fail to enable perf event\n");
		}
	}
}

/**
 * kvm_pmu_disable_counter - disable selected PMU counter
 * @vcpu: The vcpu pointer
 * @val: the value guest writes to PMCNTENCLR register
 *
 * Call perf_event_disable to stop counting the perf event
 */
void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val)
{
	int i;
	struct kvm_pmu *pmu = &vcpu->arch.pmu;
	struct kvm_pmc *pmc;

	if (!val)
		return;

	for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
		if (!(val & BIT(i)))
			continue;

		pmc = &pmu->pmc[i];
		if (pmc->perf_event)
			perf_event_disable(pmc->perf_event);
	}
}
Commit	Line	Data
051ff581 SZ	1	/*
	2	* Copyright (C) 2015 Linaro Ltd.
	3	* Author: Shannon Zhao <shannon.zhao@linaro.org>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	16	*/
	17
	18	#include <linux/cpu.h>
	19	#include <linux/kvm.h>
	20	#include <linux/kvm_host.h>
	21	#include <linux/perf_event.h>
	22	#include <asm/kvm_emulate.h>
	23	#include <kvm/arm_pmu.h>
	24
	25	/**
	26	* kvm_pmu_get_counter_value - get PMU counter value
	27	* @vcpu: The vcpu pointer
	28	* @select_idx: The counter index
	29	*/
	30	u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
	31	{
	32	u64 counter, reg, enabled, running;
	33	struct kvm_pmu *pmu = &vcpu->arch.pmu;
	34	struct kvm_pmc *pmc = &pmu->pmc[select_idx];
	35
	36	reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
	37	? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
	38	counter = vcpu_sys_reg(vcpu, reg);
	39
	40	/* The real counter value is equal to the value of counter register plus
	41	* the value perf event counts.
	42	*/
	43	if (pmc->perf_event)
	44	counter += perf_event_read_value(pmc->perf_event, &enabled,
	45	&running);
	46
	47	return counter & pmc->bitmask;
	48	}
	49
	50	/**
	51	* kvm_pmu_set_counter_value - set PMU counter value
	52	* @vcpu: The vcpu pointer
	53	* @select_idx: The counter index
	54	* @val: The counter value
	55	*/
	56	void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
	57	{
	58	u64 reg;
	59
	60	reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
	61	? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
	62	vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx);
	63	}
96b0eebc SZ	64
	65	u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu)
	66	{
	67	u64 val = vcpu_sys_reg(vcpu, PMCR_EL0) >> ARMV8_PMU_PMCR_N_SHIFT;
	68
	69	val &= ARMV8_PMU_PMCR_N_MASK;
	70	if (val == 0)
	71	return BIT(ARMV8_PMU_CYCLE_IDX);
	72	else
	73	return GENMASK(val - 1, 0) \| BIT(ARMV8_PMU_CYCLE_IDX);
	74	}
	75
	76	/**
	77	* kvm_pmu_enable_counter - enable selected PMU counter
	78	* @vcpu: The vcpu pointer
	79	* @val: the value guest writes to PMCNTENSET register
	80	*
	81	* Call perf_event_enable to start counting the perf event
	82	*/
	83	void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val)
	84	{
	85	int i;
	86	struct kvm_pmu *pmu = &vcpu->arch.pmu;
	87	struct kvm_pmc *pmc;
	88
	89	if (!(vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E) \|\| !val)
	90	return;
	91
	92	for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
	93	if (!(val & BIT(i)))
	94	continue;
	95
	96	pmc = &pmu->pmc[i];
	97	if (pmc->perf_event) {
	98	perf_event_enable(pmc->perf_event);
	99	if (pmc->perf_event->state != PERF_EVENT_STATE_ACTIVE)
	100	kvm_debug("fail to enable perf event\n");
	101	}
	102	}
	103	}
	104
	105	/**
	106	* kvm_pmu_disable_counter - disable selected PMU counter
	107	* @vcpu: The vcpu pointer
	108	* @val: the value guest writes to PMCNTENCLR register
	109	*
	110	* Call perf_event_disable to stop counting the perf event
	111	*/
	112	void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val)
	113	{
	114	int i;
	115	struct kvm_pmu *pmu = &vcpu->arch.pmu;
	116	struct kvm_pmc *pmc;
	117
	118	if (!val)
	119	return;
	120
	121	for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
	122	if (!(val & BIT(i)))
	123	continue;
	124
	125	pmc = &pmu->pmc[i];
	126	if (pmc->perf_event)
	127	perf_event_disable(pmc->perf_event);
128	}
129	}