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Date:   Thu, 7 Apr 2022 14:51:13 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     isaku.yamahata@intel.com
Cc:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        isaku.yamahata@gmail.com, Paolo Bonzini <pbonzini@redhat.com>,
        Jim Mattson <jmattson@google.com>, erdemaktas@google.com,
        Connor Kuehl <ckuehl@redhat.com>
Subject: Re: [RFC PATCH v5 092/104] KVM: TDX: Handle TDX PV HLT hypercall
Message-ID: <Yk76Yd2VTmONGA8H@google.com>
References: <cover.1646422845.git.isaku.yamahata@intel.com>
 <6da55adb2ddb6f287ebd46aad02cfaaac2088415.1646422845.git.isaku.yamahata@intel.com>
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On Fri, Mar 04, 2022, isaku.yamahata@intel.com wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
> 
> Wire up TDX PV HLT hypercall to the KVM backend function.
> 
> When the guest issues HLT, the hypercall instruction can be the right after
> CLI instruction.  Atomically unmask virtual interrupt and issue HLT
> hypercall. The virtual interrupts can arrive right after CLI instruction
> before switching back to VMM.  In such a case, the VMM should return to the
> guest without losing the interrupt.  Check if interrupts arrived before the
> TDX module switching to VMM.  And return to the guest in such cases.

Pretty sure you mean STI, not CLI.