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

commit f6edbbf36da3a27b298b66c7955fc84e1dcca305 upstream.

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.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
index 1b9844d..ee4f744 100644 (file)
--- a/arch/arm/kvm/init.S
+++ b/arch/arm/kvm/init.S
@@ -98,6 +98,10 @@ __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 2b0244d..12e26f3 100644 (file)
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -74,6 +74,10 @@ __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