From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41737) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cPaOZ-0008Qg-F5 for qemu-devel@nongnu.org; Fri, 06 Jan 2017 14:41:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cPaOW-0003GI-Pa for qemu-devel@nongnu.org; Fri, 06 Jan 2017 14:41:47 -0500 Date: Fri, 6 Jan 2017 21:41:41 +0200 From: "Michael S. Tsirkin" Message-ID: <20170106214052-mutt-send-email-mst@kernel.org> References: <20170106050451.11793-1-david@gibson.dropbear.id.au> <53dcb2da-fa15-63b0-5849-325b6edcac83@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53dcb2da-fa15-63b0-5849-325b6edcac83@redhat.com> Subject: Re: [Qemu-devel] [RFC] pxb: Restrict to x86 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcel Apfelbaum Cc: David Gibson , ehabkost@redhat.com, thuth@redhat.com, lvivier@redhat.com, qemu-ppc@nongnu.org, qemu-devel@nongnu.org On Fri, Jan 06, 2017 at 08:13:11AM +0200, Marcel Apfelbaum wrote: > On 01/06/2017 07:04 AM, David Gibson wrote: > > The PCI Expander Bridge (PXB) device is essentially a hack to allow > > different PCIe devices to be assigned to different NUMA nodes on x86. Each > > PXB is sort-of a separate PCI host bridge, except that its config space > > is shared with the config space of the main PCI host bridge, rather than > > being independent. > > > > Hi David, > > > This is only necessary if the platform doesn't (easily) allow truly > > independent PCI host bridges. AFAIK that's just x86. > > > > Indeed, it is possible to support independent PCI host bridges on x86 by > using a separate MMCONFIG space for each one and enable separate PCI domains. > We simply didn't need this until now, but maybe will be implemented it in the future. In fact I would say that's the cleanest way to do this on q35. > > This patch makes it possible to configure PXB out of the build, and adjusts > > the default configs so it's only included on x86 targets. > > > > Makes sense > > Reviewed-by: Marcel Apfelbaum > > Thanks, > Marcel > > > Signed-off-by: David Gibson > > --- > > default-configs/i386-softmmu.mak | 1 + > > default-configs/x86_64-softmmu.mak | 1 + > > hw/pci-bridge/Makefile.objs | 2 +- > > 3 files changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/default-configs/i386-softmmu.mak b/default-configs/i386-softmmu.mak > > index 0b51360..6c52d26 100644 > > --- a/default-configs/i386-softmmu.mak > > +++ b/default-configs/i386-softmmu.mak > > @@ -56,3 +56,4 @@ CONFIG_IOH3420=y > > CONFIG_I82801B11=y > > CONFIG_SMBIOS=y > > CONFIG_HYPERV_TESTDEV=$(CONFIG_KVM) > > +CONFIG_PXB=y > > diff --git a/default-configs/x86_64-softmmu.mak b/default-configs/x86_64-softmmu.mak > > index 7f89503..2d0341c 100644 > > --- a/default-configs/x86_64-softmmu.mak > > +++ b/default-configs/x86_64-softmmu.mak > > @@ -56,3 +56,4 @@ CONFIG_IOH3420=y > > CONFIG_I82801B11=y > > CONFIG_SMBIOS=y > > CONFIG_HYPERV_TESTDEV=$(CONFIG_KVM) > > +CONFIG_PXB=y > > diff --git a/hw/pci-bridge/Makefile.objs b/hw/pci-bridge/Makefile.objs > > index f2adfe3..5612bd7 100644 > > --- a/hw/pci-bridge/Makefile.objs > > +++ b/hw/pci-bridge/Makefile.objs > > @@ -1,5 +1,5 @@ > > common-obj-y += pci_bridge_dev.o > > -common-obj-y += pci_expander_bridge.o > > +common-obj-$(CONFIG_PXB) += pci_expander_bridge.o > > common-obj-$(CONFIG_XIO3130) += xio3130_upstream.o xio3130_downstream.o > > common-obj-$(CONFIG_IOH3420) += ioh3420.o > > common-obj-$(CONFIG_I82801B11) += i82801b11.o > >