From: Miaohe Lin <linmiaohe@huawei.com>
To: <pbonzini@redhat.com>, <rkrcmar@redhat.com>,
<sean.j.christopherson@intel.com>, <vkuznets@redhat.com>,
<wanpengli@tencent.com>, <jmattson@google.com>, <joro@8bytes.org>,
<tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>,
<hpa@zytor.com>
Cc: <x86@kernel.org>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <linmiaohe@huawei.com>
Subject: [PATCH] KVM: avoid unnecessary bitmap clear ops
Date: Fri, 25 Oct 2019 10:24:41 +0800 [thread overview]
Message-ID: <1571970281-20083-1-git-send-email-linmiaohe@huawei.com> (raw)
When set one bit in bitmap, there is no need to
clear it before.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
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
next reply other threads:[~2019-10-25 2:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-25 2:24 Miaohe Lin [this message]
2019-10-25 9:42 ` [PATCH] KVM: avoid unnecessary bitmap clear ops Paolo Bonzini
2019-10-25 9:49 linmiaohe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1571970281-20083-1-git-send-email-linmiaohe@huawei.com \
--to=linmiaohe@huawei.com \
--cc=bp@alien8.de \
--cc=hpa@zytor.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=rkrcmar@redhat.com \
--cc=sean.j.christopherson@intel.com \
--cc=tglx@linutronix.de \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).