All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ashish Kalra <ashish.kalra@amd.com>
To: Paolo Bonzini <pbonzini@redhat.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 09:05:23 +0000	[thread overview]
Message-ID: <20210514090523.GA21627@ashkalra_ubuntu_server> (raw)
In-Reply-To: <7ac12a36-5886-cb07-cc77-a96daa76b854@redhat.com>

Hello Boris, Paolo,

On Fri, May 14, 2021 at 10:03:18AM +0200, Paolo Bonzini wrote:
> On 14/05/21 09:33, Borislav Petkov wrote:
> > Ok, so explain to me how this looks from the user standpoint: she starts
> > migrating the guest, it fails to lookup an address, there's nothing
> > saying where it failed but the guest crashed.
> > 
> > Do you think this is user-friendly?
> 
> Ok, so explain to me how this looks from the submitter standpoint: he reads
> your review of his patch, he acknowledges your point with "Yes, it makes
> sense to signal it with a WARN or so", and still is treated as shit.
> 
> Do you think this is friendly?
> 
> 

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 ?

Thanks,
Ashish

  reply	other threads:[~2021-05-14  9:05 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 [this message]
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
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210514090523.GA21627@ashkalra_ubuntu_server \
    --to=ashish.kalra@amd.com \
    --cc=bp@alien8.de \
    --cc=brijesh.singh@amd.com \
    --cc=hpa@zytor.com \
    --cc=joro@8bytes.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=seanjc@google.com \
    --cc=srutherford@google.com \
    --cc=tglx@linutronix.de \
    --cc=thomas.lendacky@amd.com \
    --cc=venu.busireddy@oracle.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.