Commit 4a4541a4 authored Jul 22, 2012 by Avi Kivity Committed by Marcelo Tosatti Jul 30, 2012

KVM: Don't update PPR on any APIC read



The current code will update the PPR on almost any APIC read; however
that's only required if we read the PPR.

kvm_update_ppr() shows up in some profiles, albeit with a low usage (~1%).
This should reduce it further (it will still be called during interrupt
processing).

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

parent ade38c31

arch/x86/kvm/lapic.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -696,12 +696,14 @@ static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset)

		val = apic_get_tmcct(apic);
		break;

		case APIC_PROCPRI:
		apic_update_ppr(apic);
		val = apic_get_reg(apic, offset);
		break;
		case APIC_TASKPRI:
		report_tpr_access(apic, false);
		/* fall thru */
		default:
		apic_update_ppr(apic);
		val = apic_get_reg(apic, offset);
		break;
		}