linux-kernel - [PATCH 2/2] KVM: lapic: don't recalculate apic map table twice when enabling LAPIC

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Message-Id: <1470197053-3581-2-git-send-email-wanpeng.li@hotmail.com>
Date:	Wed,  3 Aug 2016 12:04:13 +0800
From:	Wanpeng Li <kernellwp@...il.com>
To:	linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:	Wanpeng Li <wanpeng.li@...mail.com>,
	Paolo Bonzini <pbonzini@...hat.com>,
	Radim Krčmář <rkrcmar@...hat.com>
Subject: [PATCH 2/2] KVM: lapic: don't recalculate apic map table twice when enabling LAPIC

From: Wanpeng Li <wanpeng.li@...mail.com>

APIC map table is recalculated during reset APIC ID to the initial value
when enabling LAPIC. This patch move the recalculate_apic_map() to the 
next branch since we don't need to recalculate apic map twice in current
codes.

Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Radim Krčmář <rkrcmar@...hat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@...mail.com>
---
 arch/x86/kvm/lapic.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 0120a58..d676f4b 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1760,9 +1760,10 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
 		if (value & MSR_IA32_APICBASE_ENABLE) {
 			kvm_apic_set_xapic_id(apic, vcpu->vcpu_id);
 			static_key_slow_dec_deferred(&apic_hw_disabled);
-		} else
+		} else {
 			static_key_slow_inc(&apic_hw_disabled.key);
-		recalculate_apic_map(vcpu->kvm);
+			recalculate_apic_map(vcpu->kvm);
+		}
 	}
 
 	if ((old_value ^ value) & X2APIC_ENABLE) {
-- 
1.9.1