From: Shannon Zhao <[email protected]> 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 <[email protected]> --- 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..97fea84 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/pmu.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_PMCR_MASK) is reset to UNKNOWN + * except PMCR.E resetting to zero. + */ + val = ((pmcr & ~ARMV8_PMCR_MASK) | (ARMV8_PMCR_MASK & 0xdecafbad)) + & (~ARMV8_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_PMCR_MASK; + val |= p->regval & ARMV8_PMCR_MASK; + vcpu_sys_reg(vcpu, PMCR_EL0) = val; + } else { + /* PMCR.P & PMCR.C are RAZ */ + val = vcpu_sys_reg(vcpu, PMCR_EL0) + & ~(ARMV8_PMCR_P | ARMV8_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 be220ee..32fee2d 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_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 -- 2.0.4 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
