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Subject: Re: [RFC] KVM: x86: Support KVM VMs sharing SEV context
To:     James Bottomley <James.Bottomley@HansenPartnership.com>,
        natet@google.com
Cc:     Ashish.Kalra@amd.com, brijesh.singh@amd.com, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, rientjes@google.com,
        seanjc@google.com, srutherford@google.com, thomas.lendacky@amd.com,
        x86@kernel.org, Tobin Feldman-Fitzthum <tobin@ibm.com>,
        DOV MURIK <Dov.Murik1@il.ibm.com>
References: <7cb132ce522728f7689618832a65e31e37788201.camel@HansenPartnership.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <0b194254-1774-e54f-b801-c2d0c0ead07c@redhat.com>
Date:   Thu, 25 Feb 2021 21:36:58 +0100
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On 25/02/21 18:53, James Bottomley wrote:
> 
> https://lore.kernel.org/qemu-devel/8b824c44-6a51-c3a7-6596-921dc47fea39@linux.ibm.com/
> 
> It sounds like this mechanism can be used to boot a vCPU through a
> mirror VM after the fact, which is very compatible with the above whose
> mechanism is  simply to steal a VCPU to hold in reset until it's
> activated.

Yes, and it's much cleaner because, for example, the extra vCPU need not 
participate in the ACPI hotplug stuff and can even use a simplified run 
loop.

Paolo