public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Eduardo Habkost <ehabkost@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jan Kiszka <jan.kiszka@web.de>,
	qemu-devel <qemu-devel@nongnu.org>, kvm <kvm@vger.kernel.org>,
	libvir-list@redhat.com
Subject: Re: kvm: "warning: host doesn't support requested feature: CPUID.01H:ECX.x2apic [bit 21]"
Date: Mon, 22 Feb 2016 18:40:28 -0300	[thread overview]
Message-ID: <20160222214028.GA3901@thinpad.lan.raisama.net> (raw)
In-Reply-To: <859622929.26459953.1455958830109.JavaMail.zimbra@redhat.com>

(CCing libvir-list)

On Sat, Feb 20, 2016 at 04:00:30AM -0500, Paolo Bonzini wrote:
> ----- Original Message -----
> > From: "Jan Kiszka" <jan.kiszka@web.de>
> > To: "Eduardo Habkost" <ehabkost@redhat.com>, "Paolo Bonzini" <pbonzini@redhat.com>
> > Cc: "qemu-devel" <qemu-devel@nongnu.org>, "kvm" <kvm@vger.kernel.org>
> > Sent: Saturday, February 20, 2016 9:09:32 AM
> > Subject: kvm: "warning: host doesn't support requested feature: CPUID.01H:ECX.x2apic [bit 21]"
> > 
> > Hi all,
> > 
> > I suppose 5120901a37 introduced this: qemu with kernel_irqchip=off now
> > generates these warnings, one per VCPU, during QEMU startup. Is the plan
> > to live with them until we finally have x2APIC emulation in userspace
> > (ie. also MSR vmexiting to there), or should we otherwise avoid it?
> 
> I think it's a bug, x2apic should be auto-suppressed with kernel_irqchip=off.

My first reaction is to dislike the idea of adding yet another
variable that affects the results of CPU models.

But considering that we are moving towards a design where libvirt
must not assume or query any low-level detail from CPU models at
all, maybe this won't be harmful.

-- 
Eduardo

  reply	other threads:[~2016-02-22 21:40 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-20  8:09 kvm: "warning: host doesn't support requested feature: CPUID.01H:ECX.x2apic [bit 21]" Jan Kiszka
2016-02-20  9:00 ` Paolo Bonzini
2016-02-22 21:40   ` Eduardo Habkost [this message]
2016-02-25  8:33   ` Lan Tianyu
2016-02-25  8:39     ` Jan Kiszka
2016-02-25 12:31       ` Lan Tianyu

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=20160222214028.GA3901@thinpad.lan.raisama.net \
    --to=ehabkost@redhat.com \
    --cc=jan.kiszka@web.de \
    --cc=kvm@vger.kernel.org \
    --cc=libvir-list@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=qemu-devel@nongnu.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox