[PATCH v12 04/21] KVM: ARM64: Add access handler for PMCR register
From: Shannon Zhao <hidden>
Date: 2016-02-22 09:37:40
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Shannon Zhao <redacted> Add reset handler which gets host value of PMCR_EL0 and make writable bits architecturally UNKNOWN except PMCR.E which is zero. Add an access handler for PMCR. Signed-off-by: Shannon Zhao <redacted> Reviewed-by: Andrew Jones <redacted> --- arch/arm64/kvm/sys_regs.c | 42 ++++++++++++++++++++++++++++++++++++++++-- include/kvm/arm_pmu.h | 4 ++++ 2 files changed, 44 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index eec3598..7ee4d5e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c@@ -34,6 +34,7 @@ #include <asm/kvm_emulate.h> #include <asm/kvm_host.h> #include <asm/kvm_mmu.h> +#include <asm/perf_event.h> #include <trace/events/kvm.h>
@@ -439,6 +440,43 @@ static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) vcpu_sys_reg(vcpu, MPIDR_EL1) = (1ULL << 31) | mpidr; } +static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +{ + u64 pmcr, val; + + asm volatile("mrs %0, pmcr_el0\n" : "=r" (pmcr)); + /* Writable bits of PMCR_EL0 (ARMV8_PMU_PMCR_MASK) is reset to UNKNOWN + * except PMCR.E resetting to zero. + */ + val = ((pmcr & ~ARMV8_PMU_PMCR_MASK) + | (ARMV8_PMU_PMCR_MASK & 0xdecafbad)) & (~ARMV8_PMU_PMCR_E); + vcpu_sys_reg(vcpu, PMCR_EL0) = val; +} + +static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 val; + + if (!kvm_arm_pmu_v3_ready(vcpu)) + return trap_raz_wi(vcpu, p, r); + + if (p->is_write) { + /* Only update writeable bits of PMCR */ + val = vcpu_sys_reg(vcpu, PMCR_EL0); + val &= ~ARMV8_PMU_PMCR_MASK; + val |= p->regval & ARMV8_PMU_PMCR_MASK; + vcpu_sys_reg(vcpu, PMCR_EL0) = val; + } else { + /* PMCR.P & PMCR.C are RAZ */ + val = vcpu_sys_reg(vcpu, PMCR_EL0) + & ~(ARMV8_PMU_PMCR_P | ARMV8_PMU_PMCR_C); + p->regval = val; + } + + 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 */ \
@@ -623,7 +661,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { /* PMCR_EL0 */ { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b000), - trap_raz_wi }, + access_pmcr, reset_pmcr, }, /* PMCNTENSET_EL0 */ { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b001), trap_raz_wi },
@@ -885,7 +923,7 @@ static const struct sys_reg_desc cp15_regs[] = { { Op1( 0), CRn( 7), CRm(14), Op2( 2), access_dcsw }, /* PMU */ - { Op1( 0), CRn( 9), CRm(12), Op2( 0), trap_raz_wi }, + { Op1( 0), CRn( 9), CRm(12), Op2( 0), access_pmcr }, { Op1( 0), CRn( 9), CRm(12), Op2( 1), trap_raz_wi }, { Op1( 0), CRn( 9), CRm(12), Op2( 2), trap_raz_wi }, { Op1( 0), CRn( 9), CRm(12), Op2( 3), trap_raz_wi },
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 3c2fd56..8157fe5 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h@@ -34,9 +34,13 @@ struct kvm_pmu { struct kvm_pmc pmc[ARMV8_PMU_MAX_COUNTERS]; bool ready; }; + +#define kvm_arm_pmu_v3_ready(v) ((v)->arch.pmu.ready) #else struct kvm_pmu { }; + +#define kvm_arm_pmu_v3_ready(v) (false) #endif #endif
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2.0.4