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From: Paolo Bonzini <pbonzini@redhat.com>
To: Sean Christopherson <seanjc@google.com>, Peter Gonda <pgonda@google.com>
Cc: kvm list <kvm@vger.kernel.org>, Marc Orr <marcorr@google.com>,
	Nathan Tempelman <natet@google.com>,
	Brijesh Singh <brijesh.singh@amd.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: SEV: Disable KVM_CAP_VM_COPY_ENC_CONTEXT_FROM for SEV-ES
Date: Wed, 15 Sep 2021 10:44:09 +0200	[thread overview]
Message-ID: <8d58d4cb-bc0b-30a9-6218-323c9ffd1037@redhat.com> (raw)
In-Reply-To: <YUDuv1aTauPz9aqo@google.com>

On 14/09/21 20:49, Sean Christopherson wrote:
> On Tue, Sep 14, 2021, Peter Gonda wrote:
>> I do not think so. You cannot call KVM_SEV_LAUNCH_UPDATE_VMSA on the mirror
>> because svm_mem_enc_op() blocks calls from the mirror. So either you have to
>> update vmsa from the mirror or have the original VM read through its mirror's
>> vCPUs when calling KVM_SEV_LAUNCH_UPDATE_VMSA. Not sure which way is better
>> but I don't see a way to do this without updating KVM.
> 
> Ah, right, I forgot all of the SEV ioctls are blocked on the mirror.  Put something
> to that effect into the changelog to squash any argument about whether or not this
> is the correct KVM behavior.

Indeed, at least KVM_SEV_LAUNCH_UPDATE_VMSA would have to be allowed in 
the mirror VM.  Do you think anything else would be necessary?

Paolo


  reply	other threads:[~2021-09-15  8:44 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-14 17:15 [PATCH] KVM: SEV: Disable KVM_CAP_VM_COPY_ENC_CONTEXT_FROM for SEV-ES Peter Gonda
2021-09-14 17:32 ` Sean Christopherson
2021-09-14 17:58   ` Peter Gonda
2021-09-14 18:41     ` Sean Christopherson
2021-09-14 18:46       ` Peter Gonda
2021-09-14 18:49         ` Sean Christopherson
2021-09-15  8:44           ` Paolo Bonzini [this message]
2021-09-15 16:10             ` Peter Gonda
2021-09-15 22:33               ` Paolo Bonzini
2021-09-16 18:08                 ` Nathan Tempelman
2021-09-16 19:00                   ` Nathan Tempelman
2021-09-21 15:04                     ` Peter Gonda

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