[PATCH 3/3] arm64: Add missing ISB after invalidating TLB in enter_vhe

[Marc Zyngier]

Although there has been a bit of back and forth on the subject,
it appears that invalidating TLBs requires an ISB instruction
after the TLBI/DSB sequence, as documented in d0b7a302d58a
("Revert "arm64: Remove unnecessary ISBs from set_{pte,pmd,pud}"").

Add the missing ISB in enter_vhe(), just in case.

Fixes: f359182291c7 ("arm64: Provide an 'upgrade to VHE' stub hypercall")
Suggested-by: Will Deacon <will at kernel.org>
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kernel/hyp-stub.S | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index ae56787ea7c1..5eccbd62fec8 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -152,6 +152,7 @@ SYM_CODE_START_LOCAL(enter_vhe)
 	// Invalidate TLBs before enabling the MMU
 	tlbi	vmalle1
 	dsb	nsh
+	isb
 
 	// Enable the EL2 S1 MMU, as set up from EL1
 	mrs_s	x0, SYS_SCTLR_EL12
-- 
2.29.2