From 4a4541a40e1fe145c72c4b959fac524a5600d9fb Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 22 Jul 2012 17:41:00 +0300 Subject: [PATCH] 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 Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/lapic.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index fff7173f6a71..ad7fff7ad13c 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -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; } -- 2.20.1