From 5c5196da4e966cc23af6a1576ad2a9e45bed3f99 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Fri, 16 Jun 2017 23:08:57 -0700 Subject: [PATCH] KVM: arm/arm64: Support EL1 phys timer register access in set/get reg Add suport for the physical timer registers in kvm_arm_timer_set_reg and kvm_arm_timer_get_reg so that these functions can be reused to interact with the rest of the system. Note that this paves part of the way for the physical timer state save/restore, but we still need to add those registers to KVM_GET_REG_LIST before we support migrating the physical timer state. Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/uapi/asm/kvm.h | 6 ++++++ arch/arm64/include/uapi/asm/kvm.h | 6 ++++++ virt/kvm/arm/arch_timer.c | 33 +++++++++++++++++++++++++++++-- 3 files changed, 43 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index 5db2d4c6a55f..665c454e50d0 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -151,6 +151,12 @@ struct kvm_arch_memory_slot { (__ARM_CP15_REG(op1, 0, crm, 0) | KVM_REG_SIZE_U64) #define ARM_CP15_REG64(...) __ARM_CP15_REG64(__VA_ARGS__) +/* PL1 Physical Timer Registers */ +#define KVM_REG_ARM_PTIMER_CTL ARM_CP15_REG32(0, 14, 2, 1) +#define KVM_REG_ARM_PTIMER_CNT ARM_CP15_REG64(0, 14) +#define KVM_REG_ARM_PTIMER_CVAL ARM_CP15_REG64(2, 14) + +/* Virtual Timer Registers */ #define KVM_REG_ARM_TIMER_CTL ARM_CP15_REG32(0, 14, 3, 1) #define KVM_REG_ARM_TIMER_CNT ARM_CP15_REG64(1, 14) #define KVM_REG_ARM_TIMER_CVAL ARM_CP15_REG64(3, 14) diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index 9f3ca24bbcc6..0004feef7cc2 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -195,6 +195,12 @@ struct kvm_arch_memory_slot { #define ARM64_SYS_REG(...) (__ARM64_SYS_REG(__VA_ARGS__) | KVM_REG_SIZE_U64) +/* Physical Timer EL0 Registers */ +#define KVM_REG_ARM_PTIMER_CTL ARM64_SYS_REG(3, 3, 14, 2, 1) +#define KVM_REG_ARM_PTIMER_CVAL ARM64_SYS_REG(3, 3, 14, 2, 2) +#define KVM_REG_ARM_PTIMER_CNT ARM64_SYS_REG(3, 3, 14, 0, 1) + +/* EL0 Virtual Timer Registers */ #define KVM_REG_ARM_TIMER_CTL ARM64_SYS_REG(3, 3, 14, 3, 1) #define KVM_REG_ARM_TIMER_CNT ARM64_SYS_REG(3, 3, 14, 3, 2) #define KVM_REG_ARM_TIMER_CVAL ARM64_SYS_REG(3, 3, 14, 0, 2) diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index ec685c1f3b78..d1a6fb12121f 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -628,10 +628,11 @@ static void kvm_timer_init_interrupt(void *info) int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value) { struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); switch (regid) { case KVM_REG_ARM_TIMER_CTL: - vtimer->cnt_ctl = value; + vtimer->cnt_ctl = value & ~ARCH_TIMER_CTRL_IT_STAT; break; case KVM_REG_ARM_TIMER_CNT: update_vtimer_cntvoff(vcpu, kvm_phys_timer_read() - value); @@ -639,6 +640,13 @@ int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value) case KVM_REG_ARM_TIMER_CVAL: vtimer->cnt_cval = value; break; + case KVM_REG_ARM_PTIMER_CTL: + ptimer->cnt_ctl = value & ~ARCH_TIMER_CTRL_IT_STAT; + break; + case KVM_REG_ARM_PTIMER_CVAL: + ptimer->cnt_cval = value; + break; + default: return -1; } @@ -647,17 +655,38 @@ int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value) return 0; } +static u64 read_timer_ctl(struct arch_timer_context *timer) +{ + /* + * Set ISTATUS bit if it's expired. + * Note that according to ARMv8 ARM Issue A.k, ISTATUS bit is + * UNKNOWN when ENABLE bit is 0, so we chose to set ISTATUS bit + * regardless of ENABLE bit for our implementation convenience. + */ + if (!kvm_timer_compute_delta(timer)) + return timer->cnt_ctl | ARCH_TIMER_CTRL_IT_STAT; + else + return timer->cnt_ctl; +} + u64 kvm_arm_timer_get_reg(struct kvm_vcpu *vcpu, u64 regid) { + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); switch (regid) { case KVM_REG_ARM_TIMER_CTL: - return vtimer->cnt_ctl; + return read_timer_ctl(vtimer); case KVM_REG_ARM_TIMER_CNT: return kvm_phys_timer_read() - vtimer->cntvoff; case KVM_REG_ARM_TIMER_CVAL: return vtimer->cnt_cval; + case KVM_REG_ARM_PTIMER_CTL: + return read_timer_ctl(ptimer); + case KVM_REG_ARM_PTIMER_CVAL: + return ptimer->cnt_cval; + case KVM_REG_ARM_PTIMER_CNT: + return kvm_phys_timer_read(); } return (u64)-1; }