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Message-ID: <b03adf94-5af2-ff5e-1dbb-6dd212790083@redhat.com>
Date:   Wed, 3 Aug 2022 19:18:05 +0200
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To:     Mingwei Zhang <mizhang@google.com>
Cc:     Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, Oliver Upton <oupton@google.com>
References: <20220802230718.1891356-1-mizhang@google.com>
 <20220802230718.1891356-2-mizhang@google.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH 1/5] KVM: x86: Get vmcs12 pages before checking pending
 interrupts
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On 8/3/22 01:07, Mingwei Zhang wrote:
> +	/*
> +	 * We must first get the vmcs12 pages before checking for interrupts
> +	 * that might unblock the guest if L1 is using virtual-interrupt
> +	 * delivery.
> +	 */
> +	if (kvm_check_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu)) {
> +		/*
> +		 * If we have to ask user-space to post-copy a page,
> +		 * then we have to keep trying to get all of the
> +		 * VMCS12 pages until we succeed.
> +		 */
> +		if (unlikely(!kvm_x86_ops.nested_ops->get_nested_state_pages(vcpu))) {
> +			kvm_make_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu);
> +			return 0;
> +		}
> +	}
> +

I think request handling (except for KVM_REQ_EVENT) could be more 
generically moved from vcpu_enter_guest() to vcpu_run().

Paolo