From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53501) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZyH76-0003zp-Jz for qemu-devel@nongnu.org; Mon, 16 Nov 2015 05:34:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZyH71-000445-Eh for qemu-devel@nongnu.org; Mon, 16 Nov 2015 05:34:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58501) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZyH71-00043P-7t for qemu-devel@nongnu.org; Mon, 16 Nov 2015 05:34:15 -0500 References: <1447601946-31248-1-git-send-email-marcel@redhat.com> <5649966C.7070702@redhat.com> <5649A770.5070908@redhat.com> <5649A857.406@redhat.com> <5649A9CA.2070309@redhat.com> <5649A9F9.5070405@redhat.com> <5649AB7F.9030702@redhat.com> <5649ABDF.1010901@redhat.com> From: Marcel Apfelbaum Message-ID: <5649B123.1050507@redhat.com> Date: Mon, 16 Nov 2015 12:34:11 +0200 MIME-Version: 1.0 In-Reply-To: <5649ABDF.1010901@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH V2 0/4] hw/pcie: Multi-root support for Q35 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , qemu-devel@nongnu.org Cc: imammedo@redhat.com, rth@twiddle.net, kraxel@redhat.com, ehabkost@redhat.com, mst@redhat.com On 11/16/2015 12:11 PM, Paolo Bonzini wrote: > > > On 16/11/2015 11:10, Marcel Apfelbaum wrote: >>> What would you lose? Hotplug? >> >> Without the bridge? Yes. However the user can add it manually the >> pci-bridge and have it anyway. > > Ok, I guess that's more or less acceptable. It's still ugly however, to > the point that I wonder if we should rename the device and call the old > one a failed experiment. > I guess we can rename the pxb to extra-root or something, but in this way will have a deprecated/duplicated device to support and kill in the future. Why not use the compat property as it is? Again, the command line *remains* the same, the difference is where the devices associated with the pxb will land: on the secondary bus (for QEMU < 2.5) or on the root bus itself (QEMU >= 2.5). I know is guest visible, but the guest will see one of them depending on the machine type. Regarding the splitting of pxb into 2 devices (pci/pcie), I have nothing against it, but because the implementation is *exactly* the same I think we should gain more by maintaining one device. Thanks, Marcel > Paolo > >> I wanted to get rid of the internal pci-bridge as a default, and this >> is why pxb and pxb-pcie are he same device now (except bus type)