KVM: PPC: Book3S HV: Fix instruction emulation

Commit 4a157d61b48c ("KVM: PPC: Book3S HV: Fix endianness of
instruction obtained from HEIR register") had the side effect that
we no longer reset vcpu->arch.last_inst to -1 on guest exit in
the cases where the instruction is not fetched from the guest.
This means that if instruction emulation turns out to be required
in those cases, the host will emulate the wrong instruction, since
vcpu->arch.last_inst will contain the last instruction that was
emulated.

This fixes it by making sure that vcpu->arch.last_inst is reset
to -1 in those cases.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index bb94e6f20c81..6cbf1630cb70 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1005,6 +1005,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
         /* Save HEIR (HV emulation assist reg) in emul_inst
            if this is an HEI (HV emulation interrupt, e40) */
         li      r3,KVM_INST_FETCH_FAILED
+        stw     r3,VCPU_LAST_INST(r9)
         cmpwi   r12,BOOK3S_INTERRUPT_H_EMUL_ASSIST
         bne     11f
         mfspr   r3,SPRN_HEIR