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Subject: Re: [PATCH 00/12] SEV Live Migration Patchset.
To:     Ashish Kalra <ashish.kalra@amd.com>
Cc:     Andy Lutomirski <luto@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Radim Krcmar <rkrcmar@redhat.com>,
        Joerg Roedel <joro@8bytes.org>, Borislav Petkov <bp@suse.de>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        David Rientjes <rientjes@google.com>, X86 ML <x86@kernel.org>,
        kvm list <kvm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Brijesh Singh <brijesh.singh@amd.com>
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 <20200319161831.GA10038@ashkalra_ubuntu_server>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <bffda827-2d9c-a6ae-f811-c6941fe03530@redhat.com>
Date:   Thu, 19 Mar 2020 17:24:51 +0100
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On 19/03/20 17:18, Ashish Kalra wrote:
>>> For the second case, we have been discussing this internally,
>>> and one option is to extend the KVM capabilites/feature bits to check for this ?
>> You could extend the hypercall to completely block live migration (e.g.
>> a0=a1=~0, a2=0 to unblock or 1 to block).  The KVM_GET_PAGE_ENC_BITMAP
>> ioctl can also return the blocked/unblocked state.
>>
> Currently i have added a new KVM para feature
> "KVM_FEATURE_SEV_LIVE_MIGRATION" to indicate host support for the SEV
> live migration feature and a custom KVM MSR "MSR_KVM_SEV_LIVE_MIG_EN"
> for the guest to enable SEV live migration. The MSR also has other
> flags for future SEV live migration extensions.

Ok, that would be fine too.  Thanks!

Paolo