kvmarm.lists.cs.columbia.edu archive mirror
 help / color / mirror / Atom feed
From: Andrew Jones <drjones@redhat.com>
To: Marc Zyngier <maz@kernel.org>
Cc: kvmarm <kvmarm@lists.cs.columbia.edu>,
	xu910121@sina.com, qemu-devel <qemu-devel@nongnu.org>,
	"Dave.Martin" <dave.martin@arm.com>
Subject: Re: Kernel patch cases qemu live migration failed.
Date: Thu, 15 Oct 2020 15:35:05 +0200	[thread overview]
Message-ID: <20201015133505.ubxvbrt6xyvl4362@kamzik.brq.redhat.com> (raw)
In-Reply-To: <7fecfc67da4caab1d677a8b4cd5386b3@kernel.org>

On Thu, Oct 15, 2020 at 12:26:10PM +0100, Marc Zyngier wrote:
> Hi
> 
> Please don't use my arm.com address anymore, nobody reads it...
> 
> On 2020-10-15 05:06, 张东旭 wrote:
> > I'm so sorry for disturbing you.
> > 
> > When I apply this kernel patch：KVM: arm64/sve: System register
> > context switch and access support
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/arm64/kvm/sys_regs.c?id=73433762fcaeb9d59e84d299021c6b15466c96dd
> 
> This patch was only introduced in 5.2, and wasn't supposed to be
> backported to anything else.

All upstream patches are backport candidates. Welcome to RHEL :-)

> 
> > qemu live migration will failed with messages：
> >               ​qemu-kvm: Invalid value 233 expecting positive value
> > <= 232
> >               qemu-kvm: Failed to load cpu:cpreg_vmstate_array_len
> > New version kernel  exclude ID_AA64ZFR0_EL1 register when host not
> > support SVE feature,
> > so qemu ioctl kvm(KVM_GET_REG_LIST) will not contain ID_AA64ZFR0_EL1
> > register.
> > 
> > I'm using CentOS Linux kernel, old kernel version：4.18.0-80.11.el8
> > (migration source)
> >       new kernel version：4.18.0-147.5.el8 (migration destination)
> > 
> > CentOS linux kernel version 4.18.0-111.el8 applied this patch. So
> > 4.18.0-147.5.el8 also applied this patch.
> > 
> > Migration source and destination hosts have the same hardware, just
> > kernel version is different,
> > and the hardware on either side of the migration not support SVE.
> > 
> > Is there some good suggestions，which can make sure old version
> > kernel live migration to new version kernel with qemu?
> 
> I['m afraid you should take this with your distribution of
> choice, unless you can reproduce the problem with mainline kernels.

I'll bet this reproduces when migrating from a mainline pre SVE register
filtering kernel to a mainline that does the filtering. I don't have
time to test that though.

Thanks,
drew

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

  reply	other threads:[~2020-10-15 13:35 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-15  4:06 Kernel patch cases qemu live migration failed 张东旭
2020-10-15 11:26 ` Marc Zyngier
2020-10-15 13:35   ` Andrew Jones [this message]
2020-10-15 13:52     ` Marc Zyngier
2020-10-15 14:41       ` Andrew Jones
2020-10-15 14:57         ` Peter Maydell
2020-10-19  9:25           ` Andrew Jones
2020-10-19 11:32             ` Dave Martin
2020-10-19 11:43               ` Peter Maydell
2020-10-19 13:40                 ` Andrew Jones
2020-10-19 14:18                   ` Peter Maydell
2020-10-19 14:58                     ` Dave Martin
2020-10-19 15:23                       ` Andrew Jones
2020-10-19 16:36                         ` Dave Martin
2020-10-15 13:26 ` Andrew Jones

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=20201015133505.ubxvbrt6xyvl4362@kamzik.brq.redhat.com \
    --to=drjones@redhat.com \
    --cc=dave.martin@arm.com \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=maz@kernel.org \
    --cc=qemu-devel@nongnu.org \
    --cc=xu910121@sina.com \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).