[PATCH v7 08/19] KVM: ARM64: Add access handler for event typer register

Shannon Zhao
2015-12-15T08:49:28Z

From: Shannon Zhao <shannon.zhao@linaro.org>

These kind of registers include PMEVTYPERn, PMCCFILTR and PMXEVTYPER
which is mapped to PMEVTYPERn or PMCCFILTR.

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 writing to these registers, create a perf_event for the selected
event type.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
---
arch/arm64/kvm/sys_regs.c | 154 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 152 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index e043224..c52ff15 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -504,6 +504,68 @@ static bool access_pmceid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
return true;
}

+static inline bool pmu_counter_idx_valid(struct kvm_vcpu *vcpu, u64 idx)
+{
+ u64 pmcr, val;
+
+ pmcr = vcpu_sys_reg(vcpu, PMCR_EL0);
+ val = (pmcr >> ARMV8_PMCR_N_SHIFT) & ARMV8_PMCR_N_MASK;
+ if (idx >= val && idx != ARMV8_CYCLE_IDX)
+ return false;
+
+ return true;
+}
+
+static bool access_pmu_evtyper(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ u64 idx, reg;
+
+ if (r->CRn == 9) {
+ /* PMXEVTYPER_EL0 */
+ reg = 0;
+ } else {
+ if (!p->is_aarch32) {
+ /* PMEVTYPERn_EL0 or PMCCFILTR_EL0 */
+ reg = r->reg;
+ } else {
+ if (r->CRn == 14 && r->CRm == 15 && r->Op2 == 7) {
+ reg = PMCCFILTR_EL0;
+ } else {
+ reg = ((r->CRm & 3) << 3) & (r->Op2 & 7);
+ reg += PMEVTYPER0_EL0;
+ }
+ }
+ }
+
+ switch (reg) {
+ case PMEVTYPER0_EL0 ... PMEVTYPER30_EL0:
+ idx = reg - PMEVTYPER0_EL0;
+ break;
+ case PMCCFILTR_EL0:
+ idx = ARMV8_CYCLE_IDX;
+ break;
+ default:
+ /* PMXEVTYPER_EL0 */
+ idx = vcpu_sys_reg(vcpu, PMSELR_EL0) & ARMV8_COUNTER_MASK;
+ if (!pmu_counter_idx_valid(vcpu, idx))
+ return true;
+
+ reg = (idx == ARMV8_CYCLE_IDX) ? PMCCFILTR_EL0
+ : PMEVTYPER0_EL0 + idx;
+ break;
+ }
+
+ if (p->is_write) {
+ kvm_pmu_set_counter_event_type(vcpu, p->regval, idx);
+ vcpu_sys_reg(vcpu, reg) = p->regval & ARMV8_EVTYPE_MASK;
+ } else {
+ p->regval = vcpu_sys_reg(vcpu, reg) & ARMV8_EVTYPE_MASK;
+ }
+
+ 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 */ \
@@ -519,6 +581,13 @@ 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 PMEVTYPERn_EL0 register */
+#define PMU_PMEVTYPER_EL0(n) \
+ /* PMEVTYPERn_EL0 */ \
+ { Op0(0b11), Op1(0b011), CRn(0b1110), \
+ CRm((0b1100 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)), \
+ access_pmu_evtyper, reset_unknown, (PMEVTYPER0_EL0 + n), }
+
/*
* Architected system registers.
* Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
@@ -715,7 +784,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
trap_raz_wi },
/* PMXEVTYPER_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b001),
- trap_raz_wi },
+ access_pmu_evtyper },
/* PMXEVCNTR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b010),
trap_raz_wi },
@@ -733,6 +802,45 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b011),
NULL, reset_unknown, TPIDRRO_EL0 },

+ /* PMEVTYPERn_EL0 */
+ PMU_PMEVTYPER_EL0(0),
+ PMU_PMEVTYPER_EL0(1),
+ PMU_PMEVTYPER_EL0(2),
+ PMU_PMEVTYPER_EL0(3),
+ PMU_PMEVTYPER_EL0(4),
+ PMU_PMEVTYPER_EL0(5),
+ PMU_PMEVTYPER_EL0(6),
+ PMU_PMEVTYPER_EL0(7),
+ PMU_PMEVTYPER_EL0(8),
+ PMU_PMEVTYPER_EL0(9),
+ PMU_PMEVTYPER_EL0(10),
+ PMU_PMEVTYPER_EL0(11),
+ PMU_PMEVTYPER_EL0(12),
+ PMU_PMEVTYPER_EL0(13),
+ PMU_PMEVTYPER_EL0(14),
+ PMU_PMEVTYPER_EL0(15),
+ PMU_PMEVTYPER_EL0(16),
+ PMU_PMEVTYPER_EL0(17),
+ PMU_PMEVTYPER_EL0(18),
+ PMU_PMEVTYPER_EL0(19),
+ PMU_PMEVTYPER_EL0(20),
+ PMU_PMEVTYPER_EL0(21),
+ PMU_PMEVTYPER_EL0(22),
+ PMU_PMEVTYPER_EL0(23),
+ PMU_PMEVTYPER_EL0(24),
+ PMU_PMEVTYPER_EL0(25),
+ PMU_PMEVTYPER_EL0(26),
+ PMU_PMEVTYPER_EL0(27),
+ PMU_PMEVTYPER_EL0(28),
+ PMU_PMEVTYPER_EL0(29),
+ PMU_PMEVTYPER_EL0(30),
+ /* PMCCFILTR_EL0
+ * This register resets as unknown in 64bit mode while it resets as zero
+ * in 32bit mode. Here we choose to reset it as zero for consistency.
+ */
+ { Op0(0b11), Op1(0b011), CRn(0b1110), CRm(0b1111), Op2(0b111),
+ access_pmu_evtyper, reset_val, PMCCFILTR_EL0, 0 },
+
/* DACR32_EL2 */
{ Op0(0b11), Op1(0b100), CRn(0b0011), CRm(0b0000), Op2(0b000),
NULL, reset_unknown, DACR32_EL2 },
@@ -922,6 +1030,13 @@ static const struct sys_reg_desc cp14_64_regs[] = {
{ Op1( 0), CRm( 2), .access = trap_raz_wi },
};

+/* Macro to expand the PMEVTYPERn register */
+#define PMU_PMEVTYPER(n) \
+ /* PMEVTYPERn */ \
+ { Op1(0), CRn(0b1110), \
+ CRm((0b1100 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)), \
+ access_pmu_evtyper }
+
/*
* Trapped cp15 registers. TTBR0/TTBR1 get a double encoding,
* depending on the way they are accessed (as a 32bit or a 64bit
@@ -958,7 +1073,7 @@ static const struct sys_reg_desc cp15_regs[] = {
{ 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( 1), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(13), Op2( 1), access_pmu_evtyper },
{ Op1( 0), CRn( 9), CRm(13), Op2( 2), trap_raz_wi },
{ Op1( 0), CRn( 9), CRm(14), Op2( 0), trap_raz_wi },
{ Op1( 0), CRn( 9), CRm(14), Op2( 1), trap_raz_wi },
@@ -973,6 +1088,41 @@ 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 },
+
+ /* PMEVTYPERn */
+ PMU_PMEVTYPER(0),
+ PMU_PMEVTYPER(1),
+ PMU_PMEVTYPER(2),
+ PMU_PMEVTYPER(3),
+ PMU_PMEVTYPER(4),
+ PMU_PMEVTYPER(5),
+ PMU_PMEVTYPER(6),
+ PMU_PMEVTYPER(7),
+ PMU_PMEVTYPER(8),
+ PMU_PMEVTYPER(9),
+ PMU_PMEVTYPER(10),
+ PMU_PMEVTYPER(11),
+ PMU_PMEVTYPER(12),
+ PMU_PMEVTYPER(13),
+ PMU_PMEVTYPER(14),
+ PMU_PMEVTYPER(15),
+ PMU_PMEVTYPER(16),
+ PMU_PMEVTYPER(17),
+ PMU_PMEVTYPER(18),
+ PMU_PMEVTYPER(19),
+ PMU_PMEVTYPER(20),
+ PMU_PMEVTYPER(21),
+ PMU_PMEVTYPER(22),
+ PMU_PMEVTYPER(23),
+ PMU_PMEVTYPER(24),
+ PMU_PMEVTYPER(25),
+ PMU_PMEVTYPER(26),
+ PMU_PMEVTYPER(27),
+ PMU_PMEVTYPER(28),
+ PMU_PMEVTYPER(29),
+ PMU_PMEVTYPER(30),
+ /* PMCCFILTR */
+ { Op1(0), CRn(14), CRm(15), Op2(7), access_pmu_evtyper },
};

static const struct sys_reg_desc cp15_64_regs[] = {
--
2.0.4