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>

2 files changed, 8 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
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index d968796f4b2d..c3191168a994 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -80,6 +80,10 @@ __do_hyp_init:
         msr     mair_el2, x4
         isb
 
+        /* Invalidate the stale TLBs from Bootloader */
+        tlbi    alle2
+        dsb     sy
+
         mrs     x4, sctlr_el2
         and     x4, x4, #SCTLR_EL2_EE   // preserve endianness of EL2
         ldr     x5, =SCTLR_EL2_FLAGS