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From: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
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Date: Tue, 22 May 2018 21:39:39 +0300
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Subject: Re: [Qemu-devel] [RFC 2/3] pci: Link pci_host_bridges with QTAILQ
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To: Zihan Yang <whois.zihan.yang@gmail.com>, qemu-devel@nongnu.org
Cc: "Michael S. Tsirkin" <mst@redhat.com>

Hi Zihan,

On 05/22/2018 08:59 AM, Zihan Yang wrote:
> >  have no objection here, we'll see later how the modification helps.
>
> The purpose is to place the q35 host at the start of queue. In the 
> original QLIST,
> when a new pxb host is added, q35 host will be bumped to the end end list.
>
> By replacing it with QTAILQ, we can always get q35 host bridges first, 
> so that
> we can make sure q35 host stays in pci domain 0. If there is no pxb host,
> the code needs not change because the 'next' field will be NULL.
>

We can use the pxb list we keep, but I don't see an issue here.

> I'm not sure whether it is necessary to let q35 host reside in pci 
> domain 0,
> but I think I'd better reserve the original when I don't know the 
> potential impact.
>

Q35 should always reside in PCI domain 0.

Thanks,
Marcel

> Thanks
> Zihan
>