From: Diana Craciun <diana.crac...@nxp.com>

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.crac...@nxp.com>
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 arch/powerpc/kvm/bookehv_interrupts.S |    4 ++++
 1 file changed, 4 insertions(+)

--- 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)


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