ARM/ARM64: KVM: Nuke Hyp-mode tlbs before enabling MMU

X-Gene u-boot runs in EL2 mode with MMU enabled hence we might
have stale EL2 tlb enteris when we enable EL2 MMU on each host CPU.

This can happen on any ARM/ARM64 board running bootloader in
Hyp-mode (or EL2-mode) with MMU enabled.

This patch ensures that we flush all Hyp-mode (or EL2-mode) TLBs
on each host CPU before enabling Hyp-mode (or EL2-mode) MMU.

Cc: <stable@vger.kernel.org>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
index 991415d978b6..3988e72d16ff 100644
--- a/arch/arm/kvm/init.S
+++ b/arch/arm/kvm/init.S
@@ -99,6 +99,10 @@ __do_hyp_init:
         mrc     p15, 0, r0, c10, c2, 1
         mcr     p15, 4, r0, c10, c2, 1
 
+        @ Invalidate the stale TLBs from Bootloader
+        mcr     p15, 4, r0, c8, c7, 0   @ TLBIALLH
+        dsb     ish
+
         @ Set the HSCTLR to:
         @  - ARM/THUMB exceptions: Kernel config (Thumb-2 kernel)
         @  - Endianness: Kernel config