arm64: KVM: move HCR_EL2.{IMO,FMO} manipulation into the vgic switch code

GICv3 requires the IMO and FMO bits to be tightly coupled with some
of the interrupt controller's register switch.

In order to have similar code paths, move the manipulation of these
bits to the GICv2 switch code.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm64/include/asm/kvm_arm.h

@@ -76,9 +76,10 @@
  */
 #define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \
 			 HCR_TVM | HCR_BSU_IS | HCR_FB | HCR_TAC | \
-			 HCR_AMO | HCR_IMO | HCR_FMO | \
-			 HCR_SWIO | HCR_TIDCP | HCR_RW)
+			 HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW)
 #define HCR_VIRT_EXCP_MASK (HCR_VA | HCR_VI | HCR_VF)
+#define HCR_INT_OVERRIDE   (HCR_FMO | HCR_IMO)
+
 
 /* Hyp System Control Register (SCTLR_EL2) bits */
 #define SCTLR_EL2_EE	(1 << 25)

arch/arm64/kvm/hyp.S

@@ -335,11 +335,8 @@
 .endm
 
 .macro activate_traps
-	ldr	x2, [x0, #VCPU_IRQ_LINES]
-	ldr	x1, [x0, #VCPU_HCR_EL2]
-	orr	x2, x2, x1
-	msr	hcr_el2, x2
-
+	ldr     x2, [x0, #VCPU_HCR_EL2]
+	msr     hcr_el2, x2
 	ldr	x2, =(CPTR_EL2_TTA)
 	msr	cptr_el2, x2
 
@@ -382,12 +379,22 @@
 	ldr	x24, [x24, VGIC_SAVE_FN]
 	kern_hyp_va	x24
 	blr	x24
+	mrs	x24, hcr_el2
+	mov	x25, #HCR_INT_OVERRIDE
+	neg	x25, x25
+	and	x24, x24, x25
+	msr	hcr_el2, x24
 .endm
 
 /*
  * Call into the vgic backend for state restoring
  */
 .macro restore_vgic_state
+	mrs	x24, hcr_el2
+	ldr	x25, [x0, #VCPU_IRQ_LINES]
+	orr	x24, x24, #HCR_INT_OVERRIDE
+	orr	x24, x24, x25
+	msr	hcr_el2, x24
 	adr	x24, __vgic_sr_vectors
 	ldr	x24, [x24, #VGIC_RESTORE_FN]
 	kern_hyp_va	x24