| Message ID | 20171219145624.46724-1-agraf@suse.de |
|---|---|
| State | Accepted |
| Commit | 81ceca05a42e24768c73d4d6dbd3701a60f1ed85 |
| Headers | show |
| Series | KVM: PPC: Book3S HV: Remove vcpu->arch.dec usage | expand |
On Tue, Dec 19, 2017 at 03:56:24PM +0100, Alexander Graf wrote: > 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@suse.de> Thanks, applied to my kvm-ppc-next branch. > 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? Yes, it looks like we do. I'm amazed no-one has noticed before. I'll fix it. Paul.
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)
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@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(-) -- 2.12.3