From patchwork Tue Feb 2 00:59:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 12188133 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41E6AC433DB for ; Tue, 2 Feb 2021 01:01:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BE2B64EBB for ; Tue, 2 Feb 2021 01:01:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229623AbhBBBBS (ORCPT ); Mon, 1 Feb 2021 20:01:18 -0500 Received: from mga06.intel.com ([134.134.136.31]:21927 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229530AbhBBBBS (ORCPT ); Mon, 1 Feb 2021 20:01:18 -0500 IronPort-SDR: C691xTVVU2WYw8bzmDaaaPqHtLWcD7/SsjE6bRoP2D6LDbKJBSG5UyKa00xiMqrWSdPluodjbn YgLhp3lu0NlA== X-IronPort-AV: E=McAfee;i="6000,8403,9882"; a="242294616" X-IronPort-AV: E=Sophos;i="5.79,393,1602572400"; d="scan'208";a="242294616" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Feb 2021 17:00:05 -0800 IronPort-SDR: gHipUTDnqhUjRZG9D/Meip7LOPQ1FilQ3Th8lxVvNpdH6l7mtKwBlaCJFhxcj6vB2PPFJ6x7C2 gmMIwjsPVelw== X-IronPort-AV: E=Sophos;i="5.79,393,1602572400"; d="scan'208";a="581764150" Received: from jambrizm-mobl1.amr.corp.intel.com (HELO bwidawsk-mobl5.local) ([10.252.133.15]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Feb 2021 17:00:04 -0800 From: Ben Widawsky To: qemu-devel@nongnu.org Cc: Ben Widawsky , linux-cxl@vger.kernel.org, Chris Browy , Dan Williams , David Hildenbrand , Igor Mammedov , Ira Weiny , Jonathan Cameron , Marcel Apfelbaum , Markus Armbruster , =?utf-8?q?Philippe_Mathieu-Daud?= =?utf-8?q?=C3=A9?= , Vishal Verma , "John Groves (jgroves)" , "Michael S. Tsirkin" Subject: [RFC PATCH v3 12/31] hw/pxb: Allow creation of a CXL PXB (host bridge) Date: Mon, 1 Feb 2021 16:59:29 -0800 Message-Id: <20210202005948.241655-13-ben.widawsky@intel.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210202005948.241655-1-ben.widawsky@intel.com> References: <20210202005948.241655-1-ben.widawsky@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org This works like adding a typical pxb device, except the name is 'pxb-cxl' instead of 'pxb-pcie'. An example command line would be as follows: -device pxb-cxl,id=cxl.0,bus="pcie.0",bus_nr=1 A CXL PXB is backward compatible with PCIe. What this means in practice is that an operating system that is unaware of CXL should still be able to enumerate this topology as if it were PCIe. One can create multiple CXL PXB host bridges, but a host bridge can only be connected to the main root bus. Host bridges cannot appear elsewhere in the topology. Note that as of this patch, the ACPI tables needed for the host bridge (specifically, an ACPI object in _SB named ACPI0016 and the CEDT) aren't created. So while this patch internally creates it, it cannot be properly used by an operating system or other system software. Upcoming patches will allow creating multiple host bridges. v2: Remove vendor and device ID (Ben) Signed-off-by: Ben Widawsky --- hw/pci-bridge/pci_expander_bridge.c | 67 ++++++++++++++++++++++++++++- hw/pci/pci.c | 7 +++ include/hw/pci/pci.h | 6 +++ 3 files changed, 78 insertions(+), 2 deletions(-) diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c index 88c45dc3b5..b42592e1ff 100644 --- a/hw/pci-bridge/pci_expander_bridge.c +++ b/hw/pci-bridge/pci_expander_bridge.c @@ -56,6 +56,10 @@ DECLARE_INSTANCE_CHECKER(PXBDev, PXB_DEV, DECLARE_INSTANCE_CHECKER(PXBDev, PXB_PCIE_DEV, TYPE_PXB_PCIE_DEVICE) +#define TYPE_PXB_CXL_DEVICE "pxb-cxl" +DECLARE_INSTANCE_CHECKER(PXBDev, PXB_CXL_DEV, + TYPE_PXB_CXL_DEVICE) + struct PXBDev { /*< private >*/ PCIDevice parent_obj; @@ -67,6 +71,11 @@ struct PXBDev { static PXBDev *convert_to_pxb(PCIDevice *dev) { + /* A CXL PXB's parent bus is PCIe, so the normal check won't work */ + if (object_dynamic_cast(OBJECT(dev), TYPE_PXB_CXL_DEVICE)) { + return PXB_CXL_DEV(dev); + } + return pci_bus_is_express(pci_get_bus(dev)) ? PXB_PCIE_DEV(dev) : PXB_DEV(dev); } @@ -111,11 +120,20 @@ static const TypeInfo pxb_pcie_bus_info = { .class_init = pxb_bus_class_init, }; +static const TypeInfo pxb_cxl_bus_info = { + .name = TYPE_PXB_CXL_BUS, + .parent = TYPE_CXL_BUS, + .instance_size = sizeof(PXBBus), + .class_init = pxb_bus_class_init, +}; + static const char *pxb_host_root_bus_path(PCIHostState *host_bridge, PCIBus *rootbus) { - PXBBus *bus = pci_bus_is_express(rootbus) ? - PXB_PCIE_BUS(rootbus) : PXB_BUS(rootbus); + PXBBus *bus = pci_bus_is_cxl(rootbus) ? + PXB_CXL_BUS(rootbus) : + pci_bus_is_express(rootbus) ? PXB_PCIE_BUS(rootbus) : + PXB_BUS(rootbus); snprintf(bus->bus_path, 8, "0000:%02x", pxb_bus_num(rootbus)); return bus->bus_path; @@ -380,13 +398,58 @@ static const TypeInfo pxb_pcie_dev_info = { }, }; +static void pxb_cxl_dev_realize(PCIDevice *dev, Error **errp) +{ + /* A CXL PXB's parent bus is still PCIe */ + if (!pci_bus_is_express(pci_get_bus(dev))) { + error_setg(errp, "pxb-cxl devices cannot reside on a PCI bus"); + return; + } + + pxb_dev_realize_common(dev, CXL, errp); +} + +static void pxb_cxl_dev_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + PCIDeviceClass *k = PCI_DEVICE_CLASS(klass); + + k->realize = pxb_cxl_dev_realize; + k->exit = pxb_dev_exitfn; + /* + * XXX: These types of bridges don't actually show up in the hierarchy so + * vendor, device, class, etc. ids are intentionally left out. + */ + + dc->desc = "CXL Host Bridge"; + device_class_set_props(dc, pxb_dev_properties); + set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories); + + /* Host bridges aren't hotpluggable. FIXME: spec reference */ + dc->hotpluggable = false; +} + +static const TypeInfo pxb_cxl_dev_info = { + .name = TYPE_PXB_CXL_DEVICE, + .parent = TYPE_PCI_DEVICE, + .instance_size = sizeof(PXBDev), + .class_init = pxb_cxl_dev_class_init, + .interfaces = + (InterfaceInfo[]){ + { INTERFACE_CONVENTIONAL_PCI_DEVICE }, + {}, + }, +}; + static void pxb_register_types(void) { type_register_static(&pxb_bus_info); type_register_static(&pxb_pcie_bus_info); + type_register_static(&pxb_cxl_bus_info); type_register_static(&pxb_host_info); type_register_static(&pxb_dev_info); type_register_static(&pxb_pcie_dev_info); + type_register_static(&pxb_cxl_dev_info); } type_init(pxb_register_types) diff --git a/hw/pci/pci.c b/hw/pci/pci.c index a45ca326ed..adbe8aa260 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -222,6 +222,12 @@ static const TypeInfo pcie_bus_info = { .class_init = pcie_bus_class_init, }; +static const TypeInfo cxl_bus_info = { + .name = TYPE_CXL_BUS, + .parent = TYPE_PCIE_BUS, + .class_init = pcie_bus_class_init, +}; + static PCIBus *pci_find_bus_nr(PCIBus *bus, int bus_num); static void pci_update_mappings(PCIDevice *d); static void pci_irq_handler(void *opaque, int irq_num, int level); @@ -2825,6 +2831,7 @@ static void pci_register_types(void) { type_register_static(&pci_bus_info); type_register_static(&pcie_bus_info); + type_register_static(&cxl_bus_info); type_register_static(&conventional_pci_interface_info); type_register_static(&cxl_interface_info); type_register_static(&pcie_interface_info); diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h index 528cef341c..bde3697bee 100644 --- a/include/hw/pci/pci.h +++ b/include/hw/pci/pci.h @@ -406,6 +406,7 @@ typedef PCIINTxRoute (*pci_route_irq_fn)(void *opaque, int pin); #define TYPE_PCI_BUS "PCI" OBJECT_DECLARE_TYPE(PCIBus, PCIBusClass, PCI_BUS) #define TYPE_PCIE_BUS "PCIE" +#define TYPE_CXL_BUS "CXL" bool pci_bus_is_express(PCIBus *bus); @@ -754,6 +755,11 @@ static inline void pci_irq_pulse(PCIDevice *pci_dev) pci_irq_deassert(pci_dev); } +static inline int pci_is_cxl(const PCIDevice *d) +{ + return d->cap_present & QEMU_PCIE_CAP_CXL; +} + static inline int pci_is_express(const PCIDevice *d) { return d->cap_present & QEMU_PCI_CAP_EXPRESS;