[PATCHv5 4/5] kvm: only sync when attention bits set

From: Michael S. Tsirkin
Date: Tue May 22 2012 - 10:05:48 EST


Commit eb0dc6d0368072236dcd086d7fdc17fd3c4574d4 introduced apic
attention bitmask but kvm still syncs lapic unconditionally.
As that commit suggested and in anticipation of adding more attention
bits, only sync lapic if(apic_attention).

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 185a2b8..3e57566 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5370,7 +5370,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
if (unlikely(vcpu->arch.tsc_always_catchup))
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);

- kvm_lapic_sync_from_vapic(vcpu);
+ if (unlikely(vcpu->arch.apic_attention))
+ kvm_lapic_sync_from_vapic(vcpu);

r = kvm_x86_ops->handle_exit(vcpu);
out:
--
MST

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