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From:   Jim Mattson <jmattson@google.com>
Date:   Fri, 18 Oct 2019 14:12:15 -0700
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Subject: Re: [PATCH v2] KVM: nVMX: Fix attempting to emulate "Acknowledge
 interrupt on exit" when there is no interrupt which L1 requires to inject to L2
To:     Wanpeng Li <kernellwp@gmail.com>
Cc:     =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        kvm <kvm@vger.kernel.org>, Paolo Bonzini <pbonzini@redhat.com>,
        Wanpeng Li <wanpeng.li@hotmail.com>,
        Dan Cross <dcross@google.com>, Marc Orr <marcorr@google.com>
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On Thu, Aug 3, 2017 at 6:23 PM Wanpeng Li <kernellwp@gmail.com> wrote:

> Thanks Radim. :) In addition, I will think more about it and figure
> out a finial solution.

Have you had any thoughts on a final solution? We're seeing incorrect
behavior with an L1 hypervisor running under qemu with "-machine
q35,kernel-irqchip=split", and I believe this may be the cause.

In particular, VMCS12 has ACK_INTERRUPT_ON_EXIT set, but L1 is seeing
an L2 exit for "external interrupt" with the VMCS12 VM-exit
interruption information cleared to 0.