From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Wanpeng Li" <wanpeng.li@hotmail.com>
Subject: [PATCH RESEND 1/3] KVM: Add vCPU running/preempted state
Date: Wed, 8 Nov 2017 18:02:12 -0800 [thread overview]
Message-ID: <1510192934-5369-2-git-send-email-wanpeng.li@hotmail.com> (raw)
In-Reply-To: <1510192934-5369-1-git-send-email-wanpeng.li@hotmail.com>
From: Wanpeng Li <wanpeng.li@hotmail.com>
This patch reuses the preempted field in kvm_steal_time, and will export
the vcpu running/pre-empted information to the guest from host. This will
enable guest to intelligently send ipi to running vcpus and set flag for
pre-empted vcpus. This will prevent waiting for vcpus that are not running.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
arch/x86/include/uapi/asm/kvm_para.h | 3 +++
arch/x86/kernel/kvm.c | 2 +-
arch/x86/kvm/x86.c | 4 ++--
3 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index a965e5b0..ff23ce9 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -50,6 +50,9 @@ struct kvm_steal_time {
__u32 pad[11];
};
+#define KVM_VCPU_NOT_PREEMPTED (0 << 0)
+#define KVM_VCPU_PREEMPTED (1 << 0)
+
#define KVM_CLOCK_PAIRING_WALLCLOCK 0
struct kvm_clock_pairing {
__s64 sec;
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 8bb9594..1b1b641 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -608,7 +608,7 @@ __visible bool __kvm_vcpu_is_preempted(long cpu)
{
struct kvm_steal_time *src = &per_cpu(steal_time, cpu);
- return !!src->preempted;
+ return !!(src->preempted & KVM_VCPU_PREEMPTED);
}
PV_CALLEE_SAVE_REGS_THUNK(__kvm_vcpu_is_preempted);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d2507c6..1ea28a2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2116,7 +2116,7 @@ static void record_steal_time(struct kvm_vcpu *vcpu)
&vcpu->arch.st.steal, sizeof(struct kvm_steal_time))))
return;
- vcpu->arch.st.steal.preempted = 0;
+ vcpu->arch.st.steal.preempted = KVM_VCPU_NOT_PREEMPTED;
if (vcpu->arch.st.steal.version & 1)
vcpu->arch.st.steal.version += 1; /* first time write, random junk */
@@ -2887,7 +2887,7 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
return;
- vcpu->arch.st.steal.preempted = 1;
+ vcpu->arch.st.steal.preempted = KVM_VCPU_PREEMPTED;
kvm_write_guest_offset_cached(vcpu->kvm, &vcpu->arch.st.stime,
&vcpu->arch.st.steal.preempted,
--
2.7.4
next prev parent reply other threads:[~2017-11-09 2:02 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-09 2:02 [PATCH RESEND 0/3] KVM: Paravirt remote TLB flush Wanpeng Li
2017-11-09 2:02 ` Wanpeng Li [this message]
2017-11-09 2:02 ` [PATCH RESEND 2/3] KVM: Add paravirt " Wanpeng Li
2017-11-09 10:48 ` Paolo Bonzini
2017-11-09 11:01 ` Wanpeng Li
2017-11-09 11:02 ` Paolo Bonzini
2017-11-09 11:08 ` Wanpeng Li
2017-11-09 15:11 ` Radim Krčmář
2017-11-09 2:02 ` [PATCH RESEND 3/3] KVM: Add flush_on_enter before guest enter Wanpeng Li
2017-11-09 10:54 ` Paolo Bonzini
2017-11-09 12:31 ` Wanpeng Li
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