[PATCH v4 04/13] KVM: arm64: nVHE: Add EL2h sync exception handler

[Pierre-Clément Tosi]

Introduce a handler for EL2h synchronous exceptions distinct from
handlers for other "invalid" exceptions when running with the nVHE host
vector. This will allow a future patch to handle kCFI (synchronous)
errors without affecting other classes of exceptions.

Signed-off-by: Pierre-Clément Tosi <ptosi at google.com>
---
 arch/arm64/kvm/hyp/nvhe/host.S | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S
index 71fb311b4c0e..bc0a73d9fcd0 100644
--- a/arch/arm64/kvm/hyp/nvhe/host.S
+++ b/arch/arm64/kvm/hyp/nvhe/host.S
@@ -183,7 +183,7 @@ SYM_FUNC_END(__host_hvc)
 .endif
 .endm
 
-.macro invalid_host_el2_vect
+.macro __host_el2_vect handler:req
 	.align 7
 
 	/*
@@ -203,7 +203,7 @@ SYM_FUNC_END(__host_hvc)
 	 * been partially clobbered by __host_enter.
 	 */
 	stp	x0, x1, [sp, #-16]!
-	b	__guest_exit_panic
+	b	\handler
 
 .L__hyp_sp_overflow\@:
 	/* Switch to the overflow stack */
@@ -213,6 +213,10 @@ SYM_FUNC_END(__host_hvc)
 	ASM_BUG()
 .endm
 
+.macro host_el2_sync_vect
+	__host_el2_vect __guest_exit_panic
+.endm
+
 .macro invalid_host_el1_vect
 	.align 7
 	mov	x0, xzr		/* restore_host = false */
@@ -222,6 +226,10 @@ SYM_FUNC_END(__host_hvc)
 	b	__hyp_do_panic
 .endm
 
+.macro invalid_host_el2_vect
+	__host_el2_vect __guest_exit_panic
+.endm
+
 /*
  * The host vector does not use an ESB instruction in order to avoid consuming
  * SErrors that should only be consumed by the host. Guest entry is deferred by
@@ -239,7 +247,7 @@ SYM_CODE_START(__kvm_hyp_host_vector)
 	invalid_host_el2_vect			// FIQ EL2t
 	invalid_host_el2_vect			// Error EL2t
 
-	invalid_host_el2_vect			// Synchronous EL2h
+	host_el2_sync_vect			// Synchronous EL2h
 	invalid_host_el2_vect			// IRQ EL2h
 	invalid_host_el2_vect			// FIQ EL2h
 	invalid_host_el2_vect			// Error EL2h
-- 
2.45.1.288.g0e0cd299f1-goog