3 files changed, 20 insertions, 7 deletions

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index a5f28e2720c7..c98ef4771c73 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -63,6 +63,7 @@
  * TAC:         Trap ACTLR
  * TSC:         Trap SMC
  * TSW:         Trap cache operations by set/way
+ * TWE:         Trap WFE
  * TWI:         Trap WFI
  * TIDCP:       Trap L2CTLR/L2ECTLR
  * BSU_IS:      Upgrade barriers to the inner shareable domain
@@ -72,8 +73,9 @@
  * FMO:         Override CPSR.F and enable signaling with VF
  * SWIO:        Turn set/way invalidates into set/way clean+invalidate
  */
-#define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWI | HCR_VM | HCR_BSU_IS | \
-                         HCR_FB | HCR_TAC | HCR_AMO | HCR_IMO | HCR_FMO | \
+#define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \
+                         HCR_BSU_IS | HCR_FB | HCR_TAC | \
+                         HCR_AMO | HCR_IMO | HCR_FMO | \
                          HCR_SWIO | HCR_TIDCP | HCR_RW)
 #define HCR_VIRT_EXCP_MASK (HCR_VA | HCR_VI | HCR_VF)
 
@@ -242,4 +244,6 @@
 
 #define ESR_EL2_EC_xABT_xFSR_EXTABT     0x10
 
+#define ESR_EL2_EC_WFI_ISS_WFE  (1 << 0)
+
 #endif /* __ARM64_KVM_ARM_H__ */
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 21e90820bd23..4480ab339a00 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -21,6 +21,7 @@ config KVM
         select MMU_NOTIFIER
         select PREEMPT_NOTIFIERS
         select ANON_INODES
+        select HAVE_KVM_CPU_RELAX_INTERCEPT
         select KVM_MMIO
         select KVM_ARM_HOST
         select KVM_ARM_VGIC
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 9beaca033437..8da56067c304 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -47,21 +47,29 @@ static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
 }
 
 /**
- * kvm_handle_wfi - handle a wait-for-interrupts instruction executed by a guest
+ * kvm_handle_wfx - handle a wait-for-interrupts or wait-for-event
+ *                  instruction executed by a guest
+ *
  * @vcpu:       the vcpu pointer
  *
- * Simply call kvm_vcpu_block(), which will halt execution of
+ * WFE: Yield the CPU and come back to this vcpu when the scheduler
+ * decides to.
+ * WFI: Simply call kvm_vcpu_block(), which will halt execution of
  * world-switches and schedule other host processes until there is an
  * incoming IRQ or FIQ to the VM.
  */
-static int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run)
+static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
-        kvm_vcpu_block(vcpu);
+        if (kvm_vcpu_get_hsr(vcpu) & ESR_EL2_EC_WFI_ISS_WFE)
+                kvm_vcpu_on_spin(vcpu);
+        else
+                kvm_vcpu_block(vcpu);
+
         return 1;
 }
 
 static exit_handle_fn arm_exit_handlers[] = {
-        [ESR_EL2_EC_WFI]        = kvm_handle_wfi,
+        [ESR_EL2_EC_WFI]        = kvm_handle_wfx,
         [ESR_EL2_EC_CP15_32]    = kvm_handle_cp15_32,
         [ESR_EL2_EC_CP15_64]    = kvm_handle_cp15_64,
         [ESR_EL2_EC_CP14_MR]    = kvm_handle_cp14_access,