From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
These kind of registers include PMEVCNTRn, PMCCNTR and PMXEVCNTR which
is mapped to PMEVCNTRn.
The access handler translates all aarch32 register offsets to aarch64
ones and uses vcpu_sys_reg() to access their values to avoid taking care
of big endian.
When reading these registers, return the sum of register value and the
value perf event counts.
Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 3 +
arch/arm64/kvm/Makefile | 1 +
arch/arm64/kvm/sys_regs.c | 139 ++++++++++++++++++++++++++++++++++++--
include/kvm/arm_pmu.h | 11 +++
virt/kvm/arm/pmu.c | 63 +++++++++++++++++
5 files changed, 213 insertions(+), 4 deletions(-)
create mode 100644 virt/kvm/arm/pmu.c
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index e342b48..627f01e 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -118,6 +118,9 @@ enum vcpu_sysreg {
/* Performance Monitors Registers */
PMCR_EL0, /* Control Register */
PMSELR_EL0, /* Event Counter Selection Register */
+ PMEVCNTR0_EL0, /* Event Counter Register (0-30) */
+ PMEVCNTR30_EL0 = PMEVCNTR0_EL0 + 30,
+ PMCCNTR_EL0, /* Cycle Counter Register */
/* 32bit specific registers. Keep them at the end of the range */
DACR32_EL2, /* Domain Access Control Register */
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index caee9ee..122cff4 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -26,3 +26,4 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v2-emul.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v3.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v3-emul.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o
+kvm-$(CONFIG_KVM_ARM_PMU) += $(KVM)/arm/pmu.o
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index ca8cdf6..ff3214b 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -513,6 +513,56 @@ static bool access_pmceid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
return true;
}
+static bool pmu_counter_idx_valid(struct kvm_vcpu *vcpu, u64 idx)
+{
+ u64 pmcr, val;
+
+ pmcr = vcpu_sys_reg(vcpu, PMCR_EL0);
+ val = (pmcr >> ARMV8_PMU_PMCR_N_SHIFT) & ARMV8_PMU_PMCR_N_MASK;
+ if (idx >= val && idx != ARMV8_PMU_CYCLE_IDX)
+ return false;
+
+ return true;
+}
+
+static bool access_pmu_evcntr(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ u64 idx;
+
+ if (!kvm_arm_pmu_v3_ready(vcpu))
+ return trap_raz_wi(vcpu, p, r);
+
+ if (r->CRn == 9 && r->CRm == 13) {
+ if (r->Op2 == 2) {
+ /* PMXEVCNTR_EL0 */
+ idx = vcpu_sys_reg(vcpu, PMSELR_EL0)
+ & ARMV8_PMU_COUNTER_MASK;
+ } else if (r->Op2 == 0) {
+ /* PMCCNTR_EL0 */
+ idx = ARMV8_PMU_CYCLE_IDX;
+ } else {
+ BUG();
+ }
+ } else if (r->CRn == 14 && (r->CRm & 12) == 8) {
+ /* PMEVCNTRn_EL0 */
+ idx = ((r->CRm & 3) << 3) | (r->Op2 & 7);
+ } else {
+ BUG();
+ }
+
+ if (!pmu_counter_idx_valid(vcpu, idx))
+ return false;
+
+ if (p->is_write)
+ kvm_pmu_set_counter_value(vcpu, idx, p->regval);
+ else
+ p->regval = kvm_pmu_get_counter_value(vcpu, idx);
+
+ return true;
+}
+
/* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
#define DBG_BCR_BVR_WCR_WVR_EL1(n) \
/* DBGBVRn_EL1 */ \
@@ -528,6 +578,13 @@ static bool access_pmceid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b111), \
trap_wcr, reset_wcr, n, 0, get_wcr, set_wcr }
+/* Macro to expand the PMEVCNTRn_EL0 register */
+#define PMU_PMEVCNTR_EL0(n) \
+ /* PMEVCNTRn_EL0 */ \
+ { Op0(0b11), Op1(0b011), CRn(0b1110), \
+ CRm((0b1000 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)), \
+ access_pmu_evcntr, reset_unknown, (PMEVCNTR0_EL0 + n), }
+
/*
* Architected system registers.
* Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
@@ -721,13 +778,13 @@ static const struct sys_reg_desc sys_reg_descs[] = {
access_pmceid },
/* PMCCNTR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b000),
- trap_raz_wi },
+ access_pmu_evcntr, reset_unknown, PMCCNTR_EL0 },
/* PMXEVTYPER_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b001),
trap_raz_wi },
/* PMXEVCNTR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b010),
- trap_raz_wi },
+ access_pmu_evcntr },
/* PMUSERENR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1110), Op2(0b000),
trap_raz_wi },
@@ -742,6 +799,39 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b011),
NULL, reset_unknown, TPIDRRO_EL0 },
+ /* PMEVCNTRn_EL0 */
+ PMU_PMEVCNTR_EL0(0),
+ PMU_PMEVCNTR_EL0(1),
+ PMU_PMEVCNTR_EL0(2),
+ PMU_PMEVCNTR_EL0(3),
+ PMU_PMEVCNTR_EL0(4),
+ PMU_PMEVCNTR_EL0(5),
+ PMU_PMEVCNTR_EL0(6),
+ PMU_PMEVCNTR_EL0(7),
+ PMU_PMEVCNTR_EL0(8),
+ PMU_PMEVCNTR_EL0(9),
+ PMU_PMEVCNTR_EL0(10),
+ PMU_PMEVCNTR_EL0(11),
+ PMU_PMEVCNTR_EL0(12),
+ PMU_PMEVCNTR_EL0(13),
+ PMU_PMEVCNTR_EL0(14),
+ PMU_PMEVCNTR_EL0(15),
+ PMU_PMEVCNTR_EL0(16),
+ PMU_PMEVCNTR_EL0(17),
+ PMU_PMEVCNTR_EL0(18),
+ PMU_PMEVCNTR_EL0(19),
+ PMU_PMEVCNTR_EL0(20),
+ PMU_PMEVCNTR_EL0(21),
+ PMU_PMEVCNTR_EL0(22),
+ PMU_PMEVCNTR_EL0(23),
+ PMU_PMEVCNTR_EL0(24),
+ PMU_PMEVCNTR_EL0(25),
+ PMU_PMEVCNTR_EL0(26),
+ PMU_PMEVCNTR_EL0(27),
+ PMU_PMEVCNTR_EL0(28),
+ PMU_PMEVCNTR_EL0(29),
+ PMU_PMEVCNTR_EL0(30),
+
/* DACR32_EL2 */
{ Op0(0b11), Op1(0b100), CRn(0b0011), CRm(0b0000), Op2(0b000),
NULL, reset_unknown, DACR32_EL2 },
@@ -931,6 +1021,13 @@ static const struct sys_reg_desc cp14_64_regs[] = {
{ Op1( 0), CRm( 2), .access = trap_raz_wi },
};
+/* Macro to expand the PMEVCNTRn register */
+#define PMU_PMEVCNTR(n) \
+ /* PMEVCNTRn */ \
+ { Op1(0), CRn(0b1110), \
+ CRm((0b1000 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)), \
+ access_pmu_evcntr }
+
/*
* Trapped cp15 registers. TTBR0/TTBR1 get a double encoding,
* depending on the way they are accessed (as a 32bit or a 64bit
@@ -966,9 +1063,9 @@ static const struct sys_reg_desc cp15_regs[] = {
{ Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmselr },
{ Op1( 0), CRn( 9), CRm(12), Op2( 6), access_pmceid },
{ Op1( 0), CRn( 9), CRm(12), Op2( 7), access_pmceid },
- { Op1( 0), CRn( 9), CRm(13), Op2( 0), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(13), Op2( 0), access_pmu_evcntr },
{ Op1( 0), CRn( 9), CRm(13), Op2( 1), trap_raz_wi },
- { Op1( 0), CRn( 9), CRm(13), Op2( 2), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(13), Op2( 2), access_pmu_evcntr },
{ Op1( 0), CRn( 9), CRm(14), Op2( 0), trap_raz_wi },
{ Op1( 0), CRn( 9), CRm(14), Op2( 1), trap_raz_wi },
{ Op1( 0), CRn( 9), CRm(14), Op2( 2), trap_raz_wi },
@@ -982,10 +1079,44 @@ static const struct sys_reg_desc cp15_regs[] = {
{ Op1( 0), CRn(12), CRm(12), Op2( 5), trap_raz_wi },
{ Op1( 0), CRn(13), CRm( 0), Op2( 1), access_vm_reg, NULL, c13_CID },
+
+ /* PMEVCNTRn */
+ PMU_PMEVCNTR(0),
+ PMU_PMEVCNTR(1),
+ PMU_PMEVCNTR(2),
+ PMU_PMEVCNTR(3),
+ PMU_PMEVCNTR(4),
+ PMU_PMEVCNTR(5),
+ PMU_PMEVCNTR(6),
+ PMU_PMEVCNTR(7),
+ PMU_PMEVCNTR(8),
+ PMU_PMEVCNTR(9),
+ PMU_PMEVCNTR(10),
+ PMU_PMEVCNTR(11),
+ PMU_PMEVCNTR(12),
+ PMU_PMEVCNTR(13),
+ PMU_PMEVCNTR(14),
+ PMU_PMEVCNTR(15),
+ PMU_PMEVCNTR(16),
+ PMU_PMEVCNTR(17),
+ PMU_PMEVCNTR(18),
+ PMU_PMEVCNTR(19),
+ PMU_PMEVCNTR(20),
+ PMU_PMEVCNTR(21),
+ PMU_PMEVCNTR(22),
+ PMU_PMEVCNTR(23),
+ PMU_PMEVCNTR(24),
+ PMU_PMEVCNTR(25),
+ PMU_PMEVCNTR(26),
+ PMU_PMEVCNTR(27),
+ PMU_PMEVCNTR(28),
+ PMU_PMEVCNTR(29),
+ PMU_PMEVCNTR(30),
};
static const struct sys_reg_desc cp15_64_regs[] = {
{ Op1( 0), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
+ { Op1( 0), CRn( 0), CRm( 9), Op2( 0), access_pmu_evcntr },
{ Op1( 0), CRn( 0), CRm(12), Op2( 0), access_gic_sgi },
{ Op1( 1), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, c2_TTBR1 },
};
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 8157fe5..bcb7698 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -23,6 +23,8 @@
#include <linux/perf_event.h>
#include <asm/perf_event.h>
+#define ARMV8_PMU_CYCLE_IDX (ARMV8_PMU_MAX_COUNTERS - 1)
+
struct kvm_pmc {
u8 idx; /* index into the pmu->pmc array */
struct perf_event *perf_event;
@@ -36,11 +38,20 @@ struct kvm_pmu {
};
#define kvm_arm_pmu_v3_ready(v) ((v)->arch.pmu.ready)
+u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx);
+void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
#else
struct kvm_pmu {
};
#define kvm_arm_pmu_v3_ready(v) (false)
+static inline u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu,
+ u64 select_idx)
+{
+ return 0;
+}
+static inline void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu,
+ u64 select_idx, u64 val) {}
#endif
#endif
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
new file mode 100644
index 0000000..cd74e63
--- /dev/null
+++ b/virt/kvm/arm/pmu.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2015 Linaro Ltd.
+ * Author: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
+ *
+ * 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);
+}
--
2.0.4
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