From 688c50aa72f64ca21767486e5eef876ec23e418c Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Wed, 4 Jan 2017 16:10:28 +0100 Subject: KVM: arm/arm64: Move timer save/restore out of the hyp code As we are about to be lazy with saving and restoring the timer registers, we prepare by moving all possible timer configuration logic out of the hyp code. All virtual timer registers can be programmed from EL1 and since the arch timer is always a level triggered interrupt we can safely do this with interrupts disabled in the host kernel on the way to the guest without taking vtimer interrupts in the host kernel (yet). The downside is that the cntvoff register can only be programmed from hyp mode, so we jump into hyp mode and back to program it. This is also safe, because the host kernel doesn't use the virtual timer in the KVM code. It may add a little performance performance penalty, but only until following commits where we move this operation to vcpu load/put. Signed-off-by: Christoffer Dall Reviewed-by: Marc Zyngier --- arch/arm/kvm/hyp/switch.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c index ebd2dd46adf7..330c9ce34ba5 100644 --- a/arch/arm/kvm/hyp/switch.c +++ b/arch/arm/kvm/hyp/switch.c @@ -174,7 +174,7 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu) __activate_vm(vcpu); __vgic_restore_state(vcpu); - __timer_restore_state(vcpu); + __timer_enable_traps(vcpu); __sysreg_restore_state(guest_ctxt); __banked_restore_state(guest_ctxt); @@ -191,7 +191,8 @@ again: __banked_save_state(guest_ctxt); __sysreg_save_state(guest_ctxt); - __timer_save_state(vcpu); + __timer_disable_traps(vcpu); + __vgic_save_state(vcpu); __deactivate_traps(vcpu); @@ -237,7 +238,7 @@ void __hyp_text __noreturn __hyp_panic(int cause) vcpu = (struct kvm_vcpu *)read_sysreg(HTPIDR); host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); - __timer_save_state(vcpu); + __timer_disable_traps(vcpu); __deactivate_traps(vcpu); __deactivate_vm(vcpu); __banked_restore_state(host_ctxt); -- cgit