linux-kernel - Re: [PATCH v2 5/5] KVM: VMX: Handle preemption timer fastpath

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <99d81fa5-dc37-b22f-be1e-4aa0449e6c26@redhat.com>
Date:   Thu, 23 Apr 2020 11:40:24 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Wanpeng Li <kernellwp@...il.com>, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>,
        Haiwei Li <lihaiwei@...cent.com>
Subject: Re: [PATCH v2 5/5] KVM: VMX: Handle preemption timer fastpath

On 23/04/20 11:01, Wanpeng Li wrote:
> +bool kvm_lapic_expired_hv_timer_fast(struct kvm_vcpu *vcpu)
> +{
> +	struct kvm_lapic *apic = vcpu->arch.apic;
> +	struct kvm_timer *ktimer = &apic->lapic_timer;
> +
> +	if (!apic_lvtt_tscdeadline(apic) ||
> +		!ktimer->hv_timer_in_use ||
> +		atomic_read(&ktimer->pending))
> +		return 0;
> +
> +	WARN_ON(swait_active(&vcpu->wq));
> +	cancel_hv_timer(apic);
> +
> +	ktimer->expired_tscdeadline = ktimer->tscdeadline;
> +	kvm_inject_apic_timer_irqs_fast(vcpu);
> +
> +	return 1;
> +}
> +EXPORT_SYMBOL_GPL(kvm_lapic_expired_hv_timer_fast);

Please re-evaluate if this is needed (or which parts are needed) after
cleaning up patch 4.  Anyway again---this is already better, I don't
like the duplicated code but at least I can understand what's going on.

Paolo