diff options
Diffstat (limited to 'virt/kvm/arm/hyp/timer-sr.c')
-rw-r--r-- | virt/kvm/arm/hyp/timer-sr.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/virt/kvm/arm/hyp/timer-sr.c b/virt/kvm/arm/hyp/timer-sr.c new file mode 100644 index 000000000000..ea00d69e7078 --- /dev/null +++ b/virt/kvm/arm/hyp/timer-sr.c @@ -0,0 +1,69 @@ +/* + * Copyright (C) 2012-2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + * + * 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 <http://www.gnu.org/licenses/>. + */ + +#include <clocksource/arm_arch_timer.h> +#include <linux/compiler.h> +#include <linux/kvm_host.h> + +#include <asm/kvm_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_el0(cntv_ctl); + timer->cntv_cval = read_sysreg_el0(cntv_cval); + } + + /* Disable the virtual timer */ + write_sysreg_el0(0, cntv_ctl); + + /* 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_el0(timer->cntv_cval, cntv_cval); + isb(); + write_sysreg_el0(timer->cntv_ctl, cntv_ctl); + } +} |