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-rw-r--r--virt/kvm/arm/arch_timer.c23
-rw-r--r--virt/kvm/arm/hyp/timer-sr.c33
2 files changed, 44 insertions, 12 deletions
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 <clocksource/arm_arch_timer.h>
#include <asm/arch_timer.h>
+#include <asm/kvm_hyp.h>
#include <kvm/arm_vgic.h>
#include <kvm/arm_arch_timer.h>
@@ -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);