On Fri, Feb 09, 2018 at 05:53:43PM +0000, Julien Grall wrote:
> Hi Christoffer,
>
> On 01/12/2018 12:07 PM, Christoffer Dall wrote:
> >The VHE switch function calls __timer_enable_traps and
> >__timer_disable_traps which don't do anything on VHE systems.
> >Therefore, simply remove these calls from the VHE switch function and
> >make the functions non-conditional as they are now only called from the
> >non-VHE switch path.
> >
> >Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> >Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
> >---
> > arch/arm64/kvm/hyp/switch.c | 2 --
> > virt/kvm/arm/hyp/timer-sr.c | 44 ++++++++++++++++++++++----------------------
> > 2 files changed, 22 insertions(+), 24 deletions(-)
> >
> >diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
> >index 9aadef6966bf..6175fcb33ed2 100644
> >--- a/arch/arm64/kvm/hyp/switch.c
> >+++ b/arch/arm64/kvm/hyp/switch.c
> >@@ -354,7 +354,6 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
> > __activate_vm(vcpu->kvm);
> > __vgic_restore_state(vcpu);
> >- __timer_enable_traps(vcpu);
> > /*
> > * We must restore the 32-bit state before the sysregs, thanks
> >@@ -373,7 +372,6 @@ int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
> > __sysreg_save_guest_state(guest_ctxt);
> > __sysreg32_save_state(vcpu);
> >- __timer_disable_traps(vcpu);
> > __vgic_save_state(vcpu);
> > __deactivate_traps(vcpu);
> >diff --git a/virt/kvm/arm/hyp/timer-sr.c b/virt/kvm/arm/hyp/timer-sr.c
> >index f24404b3c8df..77754a62eb0c 100644
> >--- a/virt/kvm/arm/hyp/timer-sr.c
> >+++ b/virt/kvm/arm/hyp/timer-sr.c
> >@@ -27,34 +27,34 @@ void __hyp_text __kvm_timer_set_cntvoff(u32 cntvoff_low, u32 cntvoff_high)
> > write_sysreg(cntvoff, cntvoff_el2);
> > }
> >+/*
> >+ * Should only be called on non-VHE systems.
> >+ * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
> >+ */
> > void __hyp_text __timer_disable_traps(struct kvm_vcpu *vcpu)
>
> Would it be worth to suffix the function with nvhe? So it would be clear
> that it should not be called for VHE system?
>
> > {
> >- /*
> >- * 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()) {
> >- u64 val;
> >+ u64 val;
> >- /* Allow physical timer/counter access for the host */
> >- val = read_sysreg(cnthctl_el2);
> >- val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
> >- write_sysreg(val, cnthctl_el2);
> >- }
> >+ /* Allow physical timer/counter access for the host */
> >+ val = read_sysreg(cnthctl_el2);
> >+ val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
> >+ write_sysreg(val, cnthctl_el2);
> > }
> >+/*
> >+ * Should only be called on non-VHE systems.
> >+ * VHE systems use EL2 timers and configure EL1 timers in kvm_timer_init_vhe().
> >+ */
> > void __hyp_text __timer_enable_traps(struct kvm_vcpu *vcpu)
>
> Same here.
>
I'll have a look.
Thanks,
-Christoffer
