From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:57450)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peterx@redhat.com>) id 1bslwY-0002bF-IL
	for qemu-devel@nongnu.org; Sat, 08 Oct 2016 03:21:15 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <peterx@redhat.com>) id 1bslwT-0001UG-8J
	for qemu-devel@nongnu.org; Sat, 08 Oct 2016 03:21:14 -0400
Received: from mx1.redhat.com ([209.132.183.28]:39466)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peterx@redhat.com>) id 1bslwT-0001Tu-21
	for qemu-devel@nongnu.org; Sat, 08 Oct 2016 03:21:09 -0400
Date: Sat, 8 Oct 2016 15:21:00 +0800
From: Peter Xu <peterx@redhat.com>
Message-ID: <20161008072100.GJ3666@pxdev.xzpeter.org>
References: <20161005130657.3399-1-rkrcmar@redhat.com>
	<20161005130657.3399-7-rkrcmar@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20161005130657.3399-7-rkrcmar@redhat.com>
Content-Transfer-Encoding: quoted-printable
Subject: Re: [Qemu-devel] [PATCH v4 6/8] intel_iommu: reject broken EIM
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>
Cc: qemu-devel@nongnu.org, Igor Mammedov <imammedo@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Richard Henderson <rth@twiddle.net>, Eduardo Habkost <ehabkost@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>

On Wed, Oct 05, 2016 at 03:06:55PM +0200, Radim Kr=C4=8Dm=C3=A1=C5=99 wro=
te:

[...]

> @@ -2472,10 +2473,22 @@ static bool vtd_decide_config(IntelIOMMUState *=
s, Error **errp)
>      }
> =20
>      if (s->intr_eim =3D=3D ON_OFF_AUTO_AUTO) {
> -        s->intr_eim =3D x86_iommu->intr_supported ?
> +        s->intr_eim =3D x86_iommu->intr_supported && kvm_irqchip_in_ke=
rnel() ?
>                                                ON_OFF_AUTO_ON : ON_OFF_=
AUTO_OFF;
>      }
> =20
> +    if (s->intr_eim =3D=3D ON_OFF_AUTO_ON) {
> +        if (kvm_irqchip_in_kernel() && !kvm_enable_x2apic()) {
> +            error_setg(errp, "eim=3Don requires support on the KVM sid=
e"
> +                             "(X2APIC_API, first shipped in v4.7)");
> +            return false;
> +        }
> +        if (!kvm_irqchip_in_kernel()) {
> +            error_setg(errp, "eim=3Don requires accel=3Dkvm,kernel-irq=
chip=3Dsplit");
> +            return false;
> +        }

I would prefer:

  if (kvm_irqchip_in_kernel()) {
      if (!kvm_enable_x2apic()) {
          error("enable x2apic failed");
          return false;
      }
  } else {
      error("need split irqchip");
      return false;
  }

But that's really a matter of taste. So:

Reviewed-by: Peter Xu <peterx@redhat.com>