diff --git a/arch/arm/include/asm/virt.h b/arch/arm/include/asm/virt.h index a2e75b84e2ae..6dae1956c74d 100644 --- a/arch/arm/include/asm/virt.h +++ b/arch/arm/include/asm/virt.h @@ -80,6 +80,11 @@ static inline bool is_kernel_in_hyp_mode(void) return false; } +static inline bool has_vhe(void) +{ + return false; +} + /* The section containing the hypervisor idmap text */ extern char __hyp_idmap_text_start[]; extern char __hyp_idmap_text_end[]; diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 11676787ad49..9d7446456e0c 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -1099,6 +1099,9 @@ static void cpu_init_hyp_mode(void *dummy) __cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr); __cpu_init_stage2(); + if (is_kernel_in_hyp_mode()) + kvm_timer_init_vhe(); + kvm_arm_init_debug(); } diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index fea10736b11f..439f6b5d31f6 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -47,6 +47,7 @@ #include #include #include +#include /* * __boot_cpu_mode records what mode CPUs were booted in. @@ -80,6 +81,14 @@ static inline bool is_kernel_in_hyp_mode(void) return read_sysreg(CurrentEL) == CurrentEL_EL2; } +static inline bool has_vhe(void) +{ + if (cpus_have_const_cap(ARM64_HAS_VIRT_HOST_EXTN)) + return true; + + return false; +} + #ifdef CONFIG_ARM64_VHE extern void verify_cpu_run_el(void); #else diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index b717ed9d2b75..5c970ce67949 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -76,4 +76,5 @@ void kvm_timer_unschedule(struct kvm_vcpu *vcpu); void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu); +void kvm_timer_init_vhe(void); #endif 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 #include +#include #include #include @@ -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); +} diff --git a/virt/kvm/arm/hyp/timer-sr.c b/virt/kvm/arm/hyp/timer-sr.c index 798866a8d875..63e28dd18bb0 100644 --- a/virt/kvm/arm/hyp/timer-sr.c +++ b/virt/kvm/arm/hyp/timer-sr.c @@ -35,10 +35,16 @@ void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu) /* 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); + /* + * We don't need to do this for VHE since the host kernel runs in EL2 + * with HCR_EL2.TGE ==1, which makes those bits have no impact. + */ + if (!has_vhe()) { + /* 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); @@ -50,14 +56,17 @@ void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu) 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); + /* Those bits are already configured at boot on VHE-system */ + if (!has_vhe()) { + /* + * 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 (timer->enabled) { write_sysreg(kvm->arch.timer.cntvoff, cntvoff_el2);