[PATCH] KVM: PPC: Book3S HV: Remove vcpu->arch.dec usage

Alexander Graf agraf at suse.de
Wed Dec 20 01:56:24 AEDT 2017

On Book3S in HV mode, we don't use the vcpu->arch.dec field at all.
Instead, all logic is built around vcpu->arch.dec_expires.

So let's remove the one remaining piece of code that was setting it.

Signed-off-by: Alexander Graf <agraf at suse.de>


Looking through the DEC logic, I fail to see any code that allows
save or restore of DEC. Do we maybe miss out on that register for
(live) migration?
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 2659844784b8..c8ffd69adfec 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -957,7 +957,6 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
 	mftb	r7
 	subf	r3,r7,r8
 	mtspr	SPRN_DEC,r3
-	std	r3,VCPU_DEC(r4)
 	ld	r5, VCPU_SPRG0(r4)
 	ld	r6, VCPU_SPRG1(r4)

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