From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54086) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cPNz2-0000C1-GQ for qemu-devel@nongnu.org; Fri, 06 Jan 2017 01:26:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cPNyx-0005MD-GL for qemu-devel@nongnu.org; Fri, 06 Jan 2017 01:26:36 -0500 Reply-To: marcel@redhat.com References: <20170106050451.11793-1-david@gibson.dropbear.id.au> <53dcb2da-fa15-63b0-5849-325b6edcac83@redhat.com> From: Marcel Apfelbaum Message-ID: <4ac9d2ba-6887-7207-b17e-d06109ccaba2@gmail.com> Date: Fri, 6 Jan 2017 08:26:25 +0200 MIME-Version: 1.0 In-Reply-To: <53dcb2da-fa15-63b0-5849-325b6edcac83@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC] pxb: Restrict to x86 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Marcel Apfelbaum , David Gibson , mst@redhat.com, ehabkost@redhat.com Cc: lvivier@redhat.com, thuth@redhat.com, qemu-ppc@nongnu.org, qemu-devel@nongnu.org On 01/06/2017 08:13 AM, 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. > >> 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 Actually ACPI based ARM guests may be able to use the PXB as well, let's wait for their opinion. Thanks, Marcel > > 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 >> > >