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Subject: Re: [PATCH v3 09/16] kvm: x86: hyperv: Use APICv deactivate request
 interface
To:     "Suthikulpanit, Suravee" <Suravee.Suthikulpanit@amd.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>
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        "jschoenh@amazon.de" <jschoenh@amazon.de>,
        "karahmed@amazon.de" <karahmed@amazon.de>,
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        "Grimm, Jon" <Jon.Grimm@amd.com>
References: <1568401242-260374-1-git-send-email-suravee.suthikulpanit@amd.com>
 <1568401242-260374-10-git-send-email-suravee.suthikulpanit@amd.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
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Date:   Wed, 9 Oct 2019 11:21:50 +0200
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On 13/09/19 21:01, Suthikulpanit, Suravee wrote:
> +	 *
> +	 * Since this requires updating
> +	 * APIC_ACCESS_PAGE_PRIVATE_MEMSLOT,
> +	 * also take srcu lock.

This comment is incorrect, it says you are entering a read-side critical
section to update the data structure.  It's only needed because
kvm_make_apicv_deactivate_request expects that it needs to unlock and
relock kvm->srcu.

Paolo

>  	 */
> -	kvm_vcpu_deactivate_apicv(vcpu);
> +	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
> +	kvm_make_apicv_deactivate_request(vcpu, true);
> +	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
> +