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Diffstat (limited to 'virt/kvm/arm/arch_timer.c')
-rw-r--r--virt/kvm/arm/arch_timer.c23
1 files changed, 23 insertions, 0 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);
+}