From: Paolo Bonzini <pbonzini@redhat.com>
To: Ashish Kalra <ashish.kalra@amd.com>
Cc: Borislav Petkov <bp@alien8.de>,
seanjc@google.com, tglx@linutronix.de, mingo@redhat.com,
hpa@zytor.com, joro@8bytes.org, thomas.lendacky@amd.com,
x86@kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, srutherford@google.com,
venu.busireddy@oracle.com, brijesh.singh@amd.com
Subject: Re: [PATCH v2 2/4] mm: x86: Invoke hypercall when page encryption status is changed
Date: Fri, 14 May 2021 11:57:27 +0200 [thread overview]
Message-ID: <70951773-fe39-c694-abeb-69052934b76b@redhat.com> (raw)
In-Reply-To: <20210514090523.GA21627@ashkalra_ubuntu_server>
On 14/05/21 11:05, Ashish Kalra wrote:
> I absolutely agree with both of your point of view. But what's the
> alternative ?
>
> Ideally we should fail/stop migration even if a single guest page
> encryption status cannot be notified and that should be the way to
> proceed in this case, the guest kernel should notify the source
> userspace VMM to block/stop migration in this case.
>
> From a practical side, i do see Qemu's migrate_add_blocker() interface
> but that looks to be a static interface and also i don't think it will
> force stop an ongoing migration, is there an existing mechanism
> to inform userspace VMM from kernel about blocking/stopping migration ?
On the Linux side, all you need to do is WARN and write 0 to the
MIGRATION_CONTROL MSR.
QEMU can check the MSR value when migrating the CPU registers at the
end, and fail migration if the MSR value is 0.
Paolo
next prev parent reply other threads:[~2021-05-14 9:57 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 15:57 [PATCH v2 0/4] Add guest support for SEV live migration Ashish Kalra
2021-04-23 15:58 ` [PATCH v2 1/4] KVM: x86: invert KVM_HYPERCALL to default to VMMCALL Ashish Kalra
2021-04-23 16:31 ` Jim Mattson
2021-04-23 17:44 ` Sean Christopherson
2021-04-23 15:58 ` [PATCH v2 2/4] mm: x86: Invoke hypercall when page encryption status is changed Ashish Kalra
2021-05-12 13:15 ` Borislav Petkov
2021-05-12 15:51 ` Sean Christopherson
2021-05-12 16:23 ` Borislav Petkov
2021-05-13 6:57 ` Ashish Kalra
2021-05-13 8:40 ` Paolo Bonzini
2021-05-13 13:49 ` Tom Lendacky
2021-05-13 4:34 ` Ashish Kalra
2021-05-14 7:33 ` Borislav Petkov
2021-05-14 8:03 ` Paolo Bonzini
2021-05-14 9:05 ` Ashish Kalra
2021-05-14 9:34 ` Borislav Petkov
2021-05-14 10:05 ` Ashish Kalra
2021-05-14 10:38 ` Borislav Petkov
2021-05-18 2:01 ` Steve Rutherford
2021-05-19 12:06 ` Ashish Kalra
2021-05-19 13:44 ` Paolo Bonzini
2021-05-14 9:57 ` Paolo Bonzini [this message]
2021-05-14 9:24 ` Borislav Petkov
2021-05-14 9:33 ` Ashish Kalra
2021-05-19 23:29 ` Andy Lutomirski
2021-05-19 23:44 ` Sean Christopherson
2021-04-23 15:59 ` [PATCH v2 3/4] EFI: Introduce the new AMD Memory Encryption GUID Ashish Kalra
2021-05-12 13:19 ` Borislav Petkov
2021-05-12 14:53 ` Ard Biesheuvel
2021-05-13 4:36 ` Ashish Kalra
2021-04-23 15:59 ` [PATCH v2 4/4] x86/kvm: Add guest support for detecting and enabling SEV Live Migration feature Ashish Kalra
2021-04-30 7:19 ` [PATCH v2 0/4] Add guest support for SEV live migration Ashish Kalra
2021-04-30 7:40 ` Paolo Bonzini
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