From mboxrd@z Thu Jan  1 00:00:00 1970
From: Brijesh Singh <brijesh.singh@amd.com>
Subject: Re: [Qemu-devel] [PATCH v6 17/23] qapi: add SEV_MEASUREMENT event
Date: Thu, 1 Feb 2018 09:25:59 -0600
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Cc: brijesh.singh@amd.com, qemu-devel@nongnu.org,
        "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>,
        Peter Maydell <peter.maydell@linaro.org>,
        Eduardo Habkost <ehabkost@redhat.com>, kvm@vger.kernel.org,
        Tom Lendacky <Thomas.Lendacky@amd.com>,
        Stefan Hajnoczi <stefanha@gmail.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Richard Henderson <richard.henderson@linaro.org>,
        "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
        Paolo Bonzini <pbonzini@redhat.com>
To: Markus Armbruster <armbru@redhat.com>
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On 01/31/2018 11:45 AM, Markus Armbruster wrote:
> Brijesh Singh <brijesh.singh@amd.com> writes:
> 
>> Add SEV_MEASUREMENT event which can be used by libvirt to get the
>> measurement of the memory regions encrypted through the SEV launch
>> flow. The measurement value is base64 encoded.
>>
>> Cc: Daniel P. Berrange <berrange@redhat.com>
>> Cc: Eric Blake <eblake@redhat.com>
>> Cc: Markus Armbruster <armbru@redhat.com>
>> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
>> ---
>>   qapi-schema.json | 13 +++++++++++++
>>   1 file changed, 13 insertions(+)
>>
>> diff --git a/qapi-schema.json b/qapi-schema.json
>> index 2046c96669bf..e1f5d14e2e3f 100644
>> --- a/qapi-schema.json
>> +++ b/qapi-schema.json
>> @@ -3192,3 +3192,16 @@
>>   # Since: 2.11
>>   ##
>>   { 'command': 'watchdog-set-action', 'data' : {'action': 'WatchdogAction'} }
>> +
>> +##
>> +# @SEV_MEASUREMENT:
>> +#
>> +# Emitted when measurement is available for the SEV guest.
>> +#
>> +# @value: measurement value encoded in base64
>> +#
>> +# Since: 2.12
>> +#
>> +##
>> +{ 'event' : 'SEV_MEASUREMENT',
>> +  'data' : { 'value' : 'str' } }
> 
> New event -> automatic question: do we need a way to poll for this
> information?  Say when an event could get lost during a libvirt restart.
> 


In our initial SEV patches for libvirt we ran into similar cases where 
the event was dropped on restart, and now leaning towards dropping this 
event patch and add a new QMP command which can be used by libvirt to 
retrieve the measurement.