From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:35545)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <davidkiarie4@gmail.com>) id 1bjPBR-0001qN-Hb
	for qemu-devel@nongnu.org; Mon, 12 Sep 2016 07:13:54 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <davidkiarie4@gmail.com>) id 1bjPBN-0007cC-A6
	for qemu-devel@nongnu.org; Mon, 12 Sep 2016 07:13:52 -0400
Received: from mail-yw0-f176.google.com ([209.85.161.176]:34229)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <davidkiarie4@gmail.com>) id 1bjPBN-0007c7-3Z
	for qemu-devel@nongnu.org; Mon, 12 Sep 2016 07:13:49 -0400
Received: by mail-yw0-f176.google.com with SMTP id g192so81692771ywh.1
	for <qemu-devel@nongnu.org>; Mon, 12 Sep 2016 04:13:49 -0700 (PDT)
MIME-Version: 1.0
In-Reply-To: <20160912110925.GF3776@pxdev.xzpeter.org>
References: <1473674889-2727-1-git-send-email-davidkiarie4@gmail.com>
	<1473674889-2727-3-git-send-email-davidkiarie4@gmail.com>
	<20160912110925.GF3776@pxdev.xzpeter.org>
From: David Kiarie <davidkiarie4@gmail.com>
Date: Mon, 12 Sep 2016 14:12:48 +0300
Message-ID: <CABdVeADkbiKWBnf4x96RALjy546S6J5twuVq613j94ujhs1+HA@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [Qemu-devel] [v4 2/6] hw/i386: enforce SID verification
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: Peter Xu <peterx@redhat.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>, Jan Kiszka <jan.kiszka@web.de>, "Michael S. Tsirkin" <mst@redhat.com>, rkrcmar@redhat.com, Eduardo Habkost <ehabkost@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Alex Williamson <alex.williamson@redhat.com>

On Mon, Sep 12, 2016 at 2:09 PM, Peter Xu <peterx@redhat.com> wrote:

> On Mon, Sep 12, 2016 at 01:08:05PM +0300, David Kiarie wrote:
>
> [...]
>
> > @@ -2252,14 +2250,17 @@ static MemTxResult vtd_mem_ir_write(void
> *opaque, hwaddr addr,
> >  {
> >      int ret = 0;
> >      MSIMessage from = {}, to = {};
> > -    uint16_t sid = X86_IOMMU_SID_INVALID;
> > +    VTDAddressSpace *as = opaque;
> > +    uint16_t sid = PCI_BUILD_BDF(pci_bus_num(as->bus), as->devfn);
>
> I remembered to have commented on this... PCI_BUILD_BDF() should be
> problematic. SID may not be built that way when with PCI bridges (or
> say, I think current code won't work with PCI bridges). Please see
> commit:
>
>     commit 4a94b3aa6d97dfa67a20c7a0315c9773352f0e8e
>     Author: Peter Xu <peterx@redhat.com>
>     Date:   Tue May 17 19:26:10 2016 +0800
>
>         pci: fix pci_requester_id()
>
> That's why we explicitly differenciate BDF and SID.
>
> I would suggest to make it simpler: we just do not do this extra
> check, and pass attrs.requester_id to vtd_interrupt_remap_msi()

directly.
>

Yes, we did discuss this but didn't come up with a conclusion so I stuck
with the check.

I will remove the check in the next version.


> Thanks,
>
> -- peterx
>