[PATCH 1/3] KVM: arm64: Constraint KVM's own __flush_dcache_area to protectected mode

[Marc Zyngier]

As we are about to specialise KVM's version of __flush_dcache_area
via a hack opn the read_ctr macro, make sure that we won't ever
use KVM's copy of __flush_dcache_area(), as things would otherwise
break for late arriving CPUs.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/hyp/nvhe/cache.S | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kvm/hyp/nvhe/cache.S b/arch/arm64/kvm/hyp/nvhe/cache.S
index 36cef6915428..1c177d3ec5c6 100644
--- a/arch/arm64/kvm/hyp/nvhe/cache.S
+++ b/arch/arm64/kvm/hyp/nvhe/cache.S
@@ -6,8 +6,12 @@
 #include <linux/linkage.h>
 #include <asm/assembler.h>
 #include <asm/alternative.h>
+#include <asm/asm-bug.h>
 
 SYM_FUNC_START_PI(__flush_dcache_area)
+alternative_if_not ARM64_KVM_PROTECTED_MODE
+	ASM_BUG()
+alternative_else_nop_endif
 	dcache_by_line_op civac, sy, x0, x1, x2, x3
 	ret
 SYM_FUNC_END_PI(__flush_dcache_area)
-- 
2.29.2