On Wed, Aug 04, 2021 at 08:58:16AM +0000, Oliver Upton wrote:
> In preparation for emulated physical counter-timer offsetting, configure
> traps on every vcpu_load() for VHE systems. As before, these trap
> settings do not affect host userspace, and are only active for the
> guest.
>
> Suggested-by: Marc Zyngier <maz@xxxxxxxxxx>
> Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx>
> ---
> arch/arm64/kvm/arch_timer.c | 10 +++++++---
> arch/arm64/kvm/arm.c | 4 +---
> include/kvm/arm_arch_timer.h | 2 --
> 3 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
> index f15058612994..9ead94aa867d 100644
> --- a/arch/arm64/kvm/arch_timer.c
> +++ b/arch/arm64/kvm/arch_timer.c
> @@ -51,6 +51,7 @@ static void kvm_arm_timer_write(struct kvm_vcpu *vcpu,
> static u64 kvm_arm_timer_read(struct kvm_vcpu *vcpu,
> struct arch_timer_context *timer,
> enum kvm_arch_timer_regs treg);
> +static void kvm_timer_enable_traps_vhe(void);
>
> u32 timer_get_ctl(struct arch_timer_context *ctxt)
> {
> @@ -668,6 +669,9 @@ void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu)
>
> if (map.emul_ptimer)
> timer_emulate(map.emul_ptimer);
> +
> + if (has_vhe())
> + kvm_timer_enable_traps_vhe();
> }
>
> bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu)
> @@ -1383,12 +1387,12 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
> }
>
> /*
> - * On VHE system, we only need to configure the EL2 timer trap register once,
> - * not for every world switch.
> + * On VHE system, we only need to configure the EL2 timer trap register on
> + * vcpu_load(), but not every world switch into the guest.
> * 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)
> +static void kvm_timer_enable_traps_vhe(void)
> {
> /* When HCR_EL2.E2H ==1, EL1PCEN and EL1PCTEN are shifted by 10 */
> u32 cnthctl_shift = 10;
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index e9a2b8f27792..47ea1e1ba80b 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -1558,9 +1558,7 @@ static void cpu_hyp_reinit(void)
>
> cpu_hyp_reset();
>
> - if (is_kernel_in_hyp_mode())
> - kvm_timer_init_vhe();
> - else
> + if (!is_kernel_in_hyp_mode())
> cpu_init_hyp_mode();
>
> cpu_set_hyp_vector();
> diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
> index 615f9314f6a5..254653b42da0 100644
> --- a/include/kvm/arm_arch_timer.h
> +++ b/include/kvm/arm_arch_timer.h
> @@ -87,8 +87,6 @@ u64 kvm_phys_timer_read(void);
> void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu);
> void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu);
>
> -void kvm_timer_init_vhe(void);
> -
> bool kvm_arch_timer_get_input_level(int vintid);
>
> #define vcpu_timer(v) (&(v)->arch.timer_cpu)
> --
> 2.32.0.605.g8dce9f2422-goog
>
Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
