From: Steve Rutherford <srutherford@google.com>
To: Ashish Kalra <Ashish.Kalra@amd.com>
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"Radim Krčmář" <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@kernel.org, "KVM list" <kvm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 10/12] mm: x86: Invoke hypercall when page encryption status is changed
Date: Wed, 19 Feb 2020 17:58:00 -0800 [thread overview]
Message-ID: <CABayD+ch3XBvJgJc+uoF6JSP0qZGq2zKHN-hTc0Vode-pi80KA@mail.gmail.com> (raw)
In-Reply-To: <a22c5b534fa035b23e549669fd5ac617b6031158.1581555616.git.ashish.kalra@amd.com>
On Wed, Feb 12, 2020 at 5:18 PM Ashish Kalra <Ashish.Kalra@amd.com> wrote:
>
> From: Brijesh Singh <brijesh.singh@amd.com>
>
> Invoke a hypercall when a memory region is changed from encrypted ->
> decrypted and vice versa. Hypervisor need to know the page encryption
> status during the guest migration.
One messy aspect, which I think is fine in practice, is that this
presumes that pages are either treated as encrypted or decrypted. If
also done on SEV, the in-place re-encryption supported by SME would
break SEV migration. Linux doesn't do this now on SEV, and I don't
have an intuition for why Linux might want this, but we will need to
ensure it is never done in order to ensure that migration works down
the line. I don't believe the AMD manual promises this will work
anyway.
Something feels a bit wasteful about having all future kernels
universally announce c-bit status when SEV is enabled, even if KVM
isn't listening, since it may be too old (or just not want to know).
Might be worth eliding the hypercalls if you get ENOSYS back? There
might be a better way of passing paravirt config metadata across than
just trying and seeing if the hypercall succeeds, but I'm not super
familiar with it.
next prev parent reply other threads:[~2020-02-20 1:58 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-13 1:14 [PATCH 00/12] SEV Live Migration Patchset Ashish Kalra
2020-02-13 1:14 ` [PATCH 01/12] KVM: SVM: Add KVM_SEV SEND_START command Ashish Kalra
2020-03-09 21:28 ` Steve Rutherford
2020-03-10 0:19 ` Steve Rutherford
2020-02-13 1:15 ` [PATCH 02/12] KVM: SVM: Add KVM_SEND_UPDATE_DATA command Ashish Kalra
2020-03-10 1:04 ` Steve Rutherford
2020-03-12 1:49 ` Ashish Kalra
2020-02-13 1:16 ` [PATCH 03/12] KVM: SVM: Add KVM_SEV_SEND_FINISH command Ashish Kalra
2020-03-10 1:09 ` Steve Rutherford
2020-02-13 1:16 ` [PATCH 04/12] KVM: SVM: Add support for KVM_SEV_RECEIVE_START command Ashish Kalra
2020-03-10 1:41 ` Steve Rutherford
2020-03-12 0:38 ` Ashish Kalra
2020-03-12 2:55 ` Steve Rutherford
2020-02-13 1:16 ` [PATCH 05/12] KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command Ashish Kalra
2020-02-13 1:16 ` [PATCH 06/12] KVM: SVM: Add KVM_SEV_RECEIVE_FINISH command Ashish Kalra
2020-02-13 1:17 ` [PATCH 07/12] KVM: x86: Add AMD SEV specific Hypercall3 Ashish Kalra
2020-02-13 1:17 ` [PATCH 08/12] KVM: X86: Introduce KVM_HC_PAGE_ENC_STATUS hypercall Ashish Kalra
2020-02-20 2:39 ` Steve Rutherford
2020-02-20 5:28 ` Ashish Kalra
2020-02-20 21:21 ` Ashish Kalra
2020-02-13 1:17 ` [PATCH 09/12] KVM: x86: Introduce KVM_GET_PAGE_ENC_BITMAP ioctl Ashish Kalra
2020-02-27 17:57 ` Venu Busireddy
2020-02-27 18:18 ` Venu Busireddy
2020-02-27 19:38 ` Ashish Kalra
2020-02-13 1:18 ` [PATCH 10/12] mm: x86: Invoke hypercall when page encryption status is changed Ashish Kalra
2020-02-13 5:42 ` Andy Lutomirski
2020-02-13 22:28 ` Ashish Kalra
2020-02-14 18:56 ` Andy Lutomirski
2020-02-14 20:36 ` Ashish Kalra
2020-02-20 1:58 ` Steve Rutherford [this message]
2020-02-20 2:12 ` Andy Lutomirski
2020-02-20 3:29 ` Steve Rutherford
2020-02-20 15:54 ` Brijesh Singh
2020-02-20 20:43 ` Steve Rutherford
2020-02-20 22:43 ` Brijesh Singh
2020-02-20 23:23 ` Steve Rutherford
2020-02-20 23:40 ` Andy Lutomirski
2020-02-13 1:18 ` [PATCH 11/12] KVM: x86: Introduce KVM_SET_PAGE_ENC_BITMAP ioctl Ashish Kalra
2020-02-13 1:18 ` [PATCH 12/12] KVM: x86: Introduce KVM_PAGE_ENC_BITMAP_RESET ioctl Ashish Kalra
2020-02-13 5:43 ` [PATCH 00/12] SEV Live Migration Patchset Andy Lutomirski
2020-02-13 23:09 ` Ashish Kalra
2020-02-14 18:58 ` Andy Lutomirski
2020-02-17 19:49 ` Ashish Kalra
2020-03-03 1:05 ` Steve Rutherford
2020-03-03 4:42 ` Ashish Kalra
2020-03-19 13:05 ` Paolo Bonzini
2020-03-19 16:18 ` Ashish Kalra
2020-03-19 16:24 ` Paolo Bonzini
2020-02-14 2:10 ` Brijesh Singh
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