From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46532) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dcwdl-0002LP-8H for qemu-devel@nongnu.org; Wed, 02 Aug 2017 12:36:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dcwdh-0006TF-A4 for qemu-devel@nongnu.org; Wed, 02 Aug 2017 12:36:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34734) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dcwdh-0006Rl-3b for qemu-devel@nongnu.org; Wed, 02 Aug 2017 12:36:53 -0400 Date: Wed, 2 Aug 2017 19:26:42 +0300 From: "Michael S. Tsirkin" Message-ID: <20170802192446-mutt-send-email-mst@kernel.org> References: <1501285073-2215-1-git-send-email-zuban32s@gmail.com> <1501285073-2215-6-git-send-email-zuban32s@gmail.com> <491f77fc-974c-33dd-3974-08ab61d2c078@redhat.com> <20170802003910-mutt-send-email-mst@kernel.org> <17a71bfc-1933-f707-2504-c9c699534cea@redhat.com> <20170802164551-mutt-send-email-mst@kernel.org> <9e36b7d6-bff3-b046-6053-162fb75ca0a0@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v3 5/5] docs: update documentation considering PCIE-PCI bridge List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcel Apfelbaum Cc: Laszlo Ersek , Alexander Bezzubikov , qemu-devel@nongnu.org, ehabkost@redhat.com, seabios@seabios.org, Kevin OConnor , Gerd Hoffmann , pbonzini@redhat.com, Igor Mammedov , rth@twiddle.net On Wed, Aug 02, 2017 at 06:36:29PM +0300, Marcel Apfelbaum wrote: > > > > > > Can dmi-pci support shpc? why doesn't it? For compatibility? > > > > > > > > > > I don't know why, but the fact that it doesn't is the reason libvirt > > > > > settled on auto-creating a dmi-pci bridge and a pci-pci bridge under > > > > > that for Q35. The reasoning was (IIRC Laine's words correctly) that the > > > > > dmi-pci bridge cannot receive hotplugged devices, while the pci-pci > > > > > bridge cannot be connected to the root complex. So both were needed. > > > > > > > > > > Thanks > > > > > Laszlo > > > > > > > > OK. Is it true that dmi-pci + pci-pci under it will allow hotplug > > > > on Q35 if we just flip the bit in _OSC? > > > > > > Marcel, what say you?... :) > > Good news, works with: > -device i82801b11-bridge,id=b1 > -device pci-bridge,id=b2,bus=b1,chassis_nr=1,msi=off And presumably it works for modern windows? OK, so it looks like patch 1 is merely a bugfix, I'll merge it for 2.10. > Notice bridge's msi=off until the following kernel bug will be merged: > https://www.spinics.net/lists/linux-pci/msg63052.html Does libvirt support msi=off as a work-around? > > Thanks, > Marcel -- MST