powerpc/fsl: Flush branch predictor when entering KVM

commit e7aa61f47b23afbec41031bc47ca8d6cb6516abc upstream.

Switching from the guest to host is another place
where the speculative accesses can be exploited.
Flush the branch predictor when entering KVM.

Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index 81bd8a07aa51f0c393cab9081e77bd316b1f6536..612b7f6a887f8a2508a2add10bd574b9417dbdea 100644 (file)
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -75,6 +75,10 @@
        PPC_LL  r1, VCPU_HOST_STACK(r4)
        PPC_LL  r2, HOST_R2(r1)
 
+START_BTB_FLUSH_SECTION
+       BTB_FLUSH(r10)
+END_BTB_FLUSH_SECTION
+
        mfspr   r10, SPRN_PID
        lwz     r8, VCPU_HOST_PID(r4)
        PPC_LL  r11, VCPU_SHARED(r4)