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Date:   Wed, 27 Oct 2021 18:14:44 +0200
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Subject: Re: [PATCH v2 35/43] KVM: SVM: Signal AVIC doorbell iff vCPU is in
 guest mode
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To:     Sean Christopherson <seanjc@google.com>
Cc:     Marc Zyngier <maz@kernel.org>, Huacai Chen <chenhuacai@kernel.org>,
        Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>,
        Paul Mackerras <paulus@ozlabs.org>,
        Anup Patel <anup.patel@wdc.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Janosch Frank <frankja@linux.ibm.com>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Atish Patra <atish.patra@wdc.com>,
        David Hildenbrand <david@redhat.com>,
        Cornelia Huck <cohuck@redhat.com>,
        Claudio Imbrenda <imbrenda@linux.ibm.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        linux-mips@vger.kernel.org, kvm@vger.kernel.org,
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        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        David Matlack <dmatlack@google.com>,
        Oliver Upton <oupton@google.com>,
        Jing Zhang <jingzhangos@google.com>
References: <20211009021236.4122790-1-seanjc@google.com>
 <20211009021236.4122790-36-seanjc@google.com>
 <0333be2a-76d8-657a-6c82-3bb5c9ff2e3b@redhat.com>
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 <185502d7-861e-fa5c-b225-419710fe77ed@redhat.com>
 <YXl5anv0Lyjx1cws@google.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
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On 27/10/21 18:08, Sean Christopherson wrote:
>> Right, so should we drop the "if (running)" check in this patch, at the same
>> time as it's adding the IN_GUEST_MODE check?
> LOL, I think we have a Three^WTwo Stooges routine going on.  This patch does
> remove avic_vcpu_is_running() and replaces it with the vcpu->mode check.  Or am
> I completely misunderstanding what your referring to?
> 
> -       if (avic_vcpu_is_running(vcpu)) {
> +       /*
> +        * Signal the doorbell to tell hardware to inject the IRQ if the vCPU
> +        * is in the guest.  If the vCPU is not in the guest, hardware will
> +        * automatically process AVIC interrupts at VMRUN.
> +        */
> +       if (vcpu->mode == IN_GUEST_MODE) {
>                  int cpu = READ_ONCE(vcpu->cpu);

Nevermind, I confused svm_deliver_avic_intr with avic_kick_target_vcpus, 
which anyway you are handling in patch 36.

Paolo