[PATCH] KVM: avoid unnecessary bitmap clear ops

From: Miaohe Lin
Date: Thu Oct 24 2019 - 22:24:22 EST


When set one bit in bitmap, there is no need to
clear it before.

Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
arch/x86/kvm/svm.c | 3 ++-
arch/x86/kvm/x86.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ca200b50cde4..d997d011a942 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2044,9 +2044,10 @@ static void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
entry &= ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK;
entry |= (h_physical_id & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK);

- entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;
if (svm->avic_is_running)
entry |= AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;
+ else
+ entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;

WRITE_ONCE(*(svm->avic_physical_id_cache), entry);
avic_update_iommu_vcpu_affinity(vcpu, h_physical_id,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ff395f812719..9b535888ea90 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1036,9 +1036,10 @@ static void kvm_update_dr7(struct kvm_vcpu *vcpu)
else
dr7 = vcpu->arch.dr7;
kvm_x86_ops->set_dr7(vcpu, dr7);
- vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_BP_ENABLED;
if (dr7 & DR7_BP_EN_MASK)
vcpu->arch.switch_db_regs |= KVM_DEBUGREG_BP_ENABLED;
+ else
+ vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_BP_ENABLED;
}

static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu)
--
2.19.1