From 1431af367e52b08038e78d346822966d968f1694 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 19 Oct 2015 16:32:20 +0100 Subject: [PATCH] arm64: KVM: Implement timer save/restore Implement the timer save restore as a direct translation of the assembly code version. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/Makefile | 1 + arch/arm64/kvm/hyp/hyp.h | 3 ++ arch/arm64/kvm/hyp/timer-sr.c | 71 ++++++++++++++++++++++++++++ include/clocksource/arm_arch_timer.h | 6 +++ 4 files changed, 81 insertions(+) create mode 100644 arch/arm64/kvm/hyp/timer-sr.c diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile index d1e38ce16bb5..455dc0a3acb5 100644 --- a/arch/arm64/kvm/hyp/Makefile +++ b/arch/arm64/kvm/hyp/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-sr.o obj-$(CONFIG_KVM_ARM_HOST) += vgic-v3-sr.o +obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h index 5759f9f5ef14..f213e4652bbf 100644 --- a/arch/arm64/kvm/hyp/hyp.h +++ b/arch/arm64/kvm/hyp/hyp.h @@ -35,5 +35,8 @@ void __vgic_v2_restore_state(struct kvm_vcpu *vcpu); void __vgic_v3_save_state(struct kvm_vcpu *vcpu); void __vgic_v3_restore_state(struct kvm_vcpu *vcpu); +void __timer_save_state(struct kvm_vcpu *vcpu); +void __timer_restore_state(struct kvm_vcpu *vcpu); + #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kvm/hyp/timer-sr.c b/arch/arm64/kvm/hyp/timer-sr.c new file mode 100644 index 000000000000..1051e5d7320f --- /dev/null +++ b/arch/arm64/kvm/hyp/timer-sr.c @@ -0,0 +1,71 @@ +/* + * Copyright (C) 2012-2015 - ARM Ltd + * Author: Marc Zyngier + * + * 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 . + */ + +#include +#include +#include + +#include + +#include "hyp.h" + +/* vcpu is already in the HYP VA space */ +void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = kern_hyp_va(vcpu->kvm); + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + u64 val; + + if (kvm->arch.timer.enabled) { + timer->cntv_ctl = read_sysreg(cntv_ctl_el0); + timer->cntv_cval = read_sysreg(cntv_cval_el0); + } + + /* Disable the virtual timer */ + write_sysreg(0, cntv_ctl_el0); + + /* Allow physical timer/counter access for the host */ + val = read_sysreg(cnthctl_el2); + val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN; + write_sysreg(val, cnthctl_el2); + + /* Clear cntvoff for the host */ + write_sysreg(0, cntvoff_el2); +} + +void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = kern_hyp_va(vcpu->kvm); + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + u64 val; + + /* + * Disallow physical timer access for the guest + * Physical counter access is allowed + */ + val = read_sysreg(cnthctl_el2); + val &= ~CNTHCTL_EL1PCEN; + val |= CNTHCTL_EL1PCTEN; + write_sysreg(val, cnthctl_el2); + + if (kvm->arch.timer.enabled) { + write_sysreg(kvm->arch.timer.cntvoff, cntvoff_el2); + write_sysreg(timer->cntv_cval, cntv_cval_el0); + isb(); + write_sysreg(timer->cntv_ctl, cntv_ctl_el0); + } +} diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h index 9916d0e4eff5..25d0914481a2 100644 --- a/include/clocksource/arm_arch_timer.h +++ b/include/clocksource/arm_arch_timer.h @@ -23,6 +23,12 @@ #define ARCH_TIMER_CTRL_IT_MASK (1 << 1) #define ARCH_TIMER_CTRL_IT_STAT (1 << 2) +#define CNTHCTL_EL1PCTEN (1 << 0) +#define CNTHCTL_EL1PCEN (1 << 1) +#define CNTHCTL_EVNTEN (1 << 2) +#define CNTHCTL_EVNTDIR (1 << 3) +#define CNTHCTL_EVNTI (0xF << 4) + enum arch_timer_reg { ARCH_TIMER_REG_CTRL, ARCH_TIMER_REG_TVAL, -- 2.20.1