[PATCH v4 16/40] KVM: arm64: Remove noop calls to timer save/restore from VHE switch
From: Christoffer Dall <hidden>
Date: 2018-02-15 21:03:08
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
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 <redacted>
Signed-off-by: Christoffer Dall <redacted>
---
Notes:
Changes since v2:
- Added comment explaining the timer enable/disable functions
are for !VHE only.
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 734dac7f808f..f0fae320edc0 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c@@ -379,7 +379,6 @@ 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
@@ -400,7 +399,6 @@ 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) { - /* - * 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) { - if (!has_vhe()) { - u64 val; + 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); - } + /* + * 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); }
--
2.14.2