From: Paolo Bonzini <pbonzini@redhat.com>
To: Wanpeng Li <kernellwp@gmail.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Haiwei Li <lihaiwei@tencent.com>
Subject: Re: [PATCH v2 4/5] KVM: X86: TSCDEADLINE MSR emulation fastpath
Date: Thu, 23 Apr 2020 11:37:00 +0200 [thread overview]
Message-ID: <1309372a-0dcf-cba6-9d65-e50139bbe46b@redhat.com> (raw)
In-Reply-To: <1587632507-18997-5-git-send-email-wanpengli@tencent.com>
On 23/04/20 11:01, Wanpeng Li wrote:
> +
> +void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data)
> +{
> + if (__kvm_set_lapic_tscdeadline_msr(vcpu, data))
> + start_apic_timer(vcpu->arch.apic);
> +}
> +
> +int kvm_set_lapic_tscdeadline_msr_fast(struct kvm_vcpu *vcpu, u64 data)
> +{
> + struct kvm_lapic *apic = vcpu->arch.apic;
> +
> + if (__kvm_set_lapic_tscdeadline_msr(vcpu, data)) {
> + atomic_set(&apic->lapic_timer.pending, 0);
> + if (start_hv_timer(apic))
> + return tscdeadline_expired_timer_fast(vcpu);
> + }
> +
> + return 1;
> }
>
> +static int tscdeadline_expired_timer_fast(struct kvm_vcpu *vcpu)
> +{
> + if (kvm_check_request(KVM_REQ_PENDING_TIMER, vcpu)) {
> + kvm_clear_request(KVM_REQ_PENDING_TIMER, vcpu);
> + kvm_inject_apic_timer_irqs_fast(vcpu);
> + atomic_set(&vcpu->arch.apic->lapic_timer.pending, 0);
> + }
> +
> + return 0;
> +}
This could also be handled in apic_timer_expired. For example you can
add an argument from_timer_fn and do
if (!from_timer_fn) {
WARN_ON(kvm_get_running_vcpu() != vcpu);
kvm_inject_apic_timer_irqs_fast(vcpu);
return;
}
if (kvm_use_posted_timer_interrupt(apic->vcpu)) {
...
}
atomic_inc(&apic->lapic_timer.pending);
kvm_set_pending_timer(vcpu);
and then you don't need kvm_set_lapic_tscdeadline_msr_fast and
everything else. Anyway thanks, this is already much better.
Paoo
next prev parent reply other threads:[~2020-04-23 9:39 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-23 9:01 [PATCH v2 0/5] KVM: VMX: Tscdeadline timer emulation fastpath Wanpeng Li
2020-04-23 9:01 ` [PATCH v2 1/5] KVM: LAPIC: Introduce interrupt delivery fastpath Wanpeng Li
2020-04-23 9:25 ` Paolo Bonzini
2020-04-23 9:35 ` Wanpeng Li
2020-04-23 9:39 ` Paolo Bonzini
2020-04-23 9:44 ` Wanpeng Li
2020-04-23 9:52 ` Paolo Bonzini
2020-04-23 9:01 ` [PATCH v2 2/5] KVM: X86: Introduce need_cancel_enter_guest helper Wanpeng Li
2020-04-23 9:01 ` [PATCH v2 3/5] KVM: VMX: Introduce generic fastpath handler Wanpeng Li
2020-04-23 9:01 ` [PATCH v2 4/5] KVM: X86: TSCDEADLINE MSR emulation fastpath Wanpeng Li
2020-04-23 9:37 ` Paolo Bonzini [this message]
2020-04-23 9:54 ` Wanpeng Li
2020-04-23 10:28 ` Paolo Bonzini
2020-04-23 9:01 ` [PATCH v2 5/5] KVM: VMX: Handle preemption timer fastpath Wanpeng Li
2020-04-23 9:40 ` Paolo Bonzini
2020-04-23 9:56 ` Wanpeng Li
2020-04-23 10:29 ` Paolo Bonzini
2020-04-24 6:38 ` Wanpeng Li
2020-04-26 7:38 ` kbuild test robot
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