Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [RFC PATCH 00/35] SEV-ES hypervisor support
To:     Sean Christopherson <seanjc@google.com>
Cc:     Tom Lendacky <thomas.lendacky@amd.com>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, x86@kernel.org,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Brijesh Singh <brijesh.singh@amd.com>,
        Xiaoyao Li <xiaoyao.li@intel.com>,
        Isaku Yamahata <isaku.yamahata@intel.com>
References: <cover.1600114548.git.thomas.lendacky@amd.com>
 <20200914225951.GM7192@sjchrist-ice>
 <bee6fdda-d548-8af5-f029-25c22165bf84@amd.com>
 <20200916001925.GL8420@sjchrist-ice>
 <60cbddaf-50f3-72ca-f673-ff0b421db3ad@redhat.com>
 <X8U2gyj7F2wFU3JI@google.com>
 <8759948d-aa0b-3929-bda6-488b6788489a@redhat.com>
 <X8VJdxTKKkC7uEMh@google.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <fce53908-4b7b-5ef1-eb60-360a505b21d3@redhat.com>
Date:   Mon, 30 Nov 2020 21:24:33 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.4.0
MIME-Version: 1.0
In-Reply-To: <X8VJdxTKKkC7uEMh@google.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 30/11/20 20:35, Sean Christopherson wrote:
>> Delayed interrupts are fine, since they are injected according to RVI and
>> the posted interrupt descriptor.  I'm thinking more of events (exceptions
>> and interrupts) that caused an EPT violation exit and were recorded in the
>> IDT-vectored info field.
> Ah.  As is, I don't believe KVM has access to this information.  TDX-Module
> handles the actual EPT violation, as well as event reinjection.  The EPT
> violation reported by SEAMRET is synthesized, and IIRC the IDT-vectoring field
> is not readable.
> 
> Regardless, is there an actual a problem with having a "pending" exception that
> isn't reported to userspace?  Obviously the info needs to be migrated, but that
> will be taken care of by virtue of migrating the VMCS.

No problem, I suppose we would just have to get used to not being able 
to look into the state of migrated VMs.

Paolo