diff options
Diffstat (limited to 'virt/kvm/arm/arch_timer.c')
| -rw-r--r-- | virt/kvm/arm/arch_timer.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index a7fe6062b65a..6a084cd57b88 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -24,6 +24,7 @@ #include <clocksource/arm_arch_timer.h> #include <asm/arch_timer.h> +#include <asm/kvm_hyp.h> #include <kvm/arm_vgic.h> #include <kvm/arm_arch_timer.h> @@ -509,3 +510,25 @@ void kvm_timer_init(struct kvm *kvm) { kvm->arch.timer.cntvoff = kvm_phys_timer_read(); } + +/* + * On VHE system, we only need to configure trap on physical timer and counter + * accesses in EL0 and EL1 once, not for every world switch. + * The host kernel runs at EL2 with HCR_EL2.TGE == 1, + * and this makes those bits have no effect for the host kernel execution. + */ +void kvm_timer_init_vhe(void) +{ + /* When HCR_EL2.E2H ==1, EL1PCEN and EL1PCTEN are shifted by 10 */ + u32 cnthctl_shift = 10; + u64 val; + + /* + * Disallow physical timer access for the guest. + * Physical counter access is allowed. + */ + val = read_sysreg(cnthctl_el2); + val &= ~(CNTHCTL_EL1PCEN << cnthctl_shift); + val |= (CNTHCTL_EL1PCTEN << cnthctl_shift); + write_sysreg(val, cnthctl_el2); +} |