From patchwork Tue Jul 19 17:42:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Tyshchenko X-Patchwork-Id: 12922847 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 97557CCA48A for ; Tue, 19 Jul 2022 17:43:37 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.370807.602761 (Exim 4.92) (envelope-from ) id 1oDrFj-0008Jh-57; Tue, 19 Jul 2022 17:43:23 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 370807.602761; Tue, 19 Jul 2022 17:43:23 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oDrFi-0008ID-Pb; Tue, 19 Jul 2022 17:43:22 +0000 Received: by outflank-mailman (input) for mailman id 370807; Tue, 19 Jul 2022 17:43:21 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oDrFh-00065X-Em for xen-devel@lists.xenproject.org; Tue, 19 Jul 2022 17:43:21 +0000 Received: from mail-ed1-x52b.google.com (mail-ed1-x52b.google.com [2a00:1450:4864:20::52b]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 478036d2-078a-11ed-924f-1f966e50362f; Tue, 19 Jul 2022 19:43:20 +0200 (CEST) Received: by mail-ed1-x52b.google.com with SMTP id m16so20604833edb.11 for ; Tue, 19 Jul 2022 10:43:20 -0700 (PDT) Received: from otyshchenko.router ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id wj18-20020a170907051200b0072af92fa086sm6903268ejb.32.2022.07.19.10.43.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Jul 2022 10:43:19 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 478036d2-078a-11ed-924f-1f966e50362f DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rMoBmnl3ZpBTv1UmtiTdiuto4NAuEX1ahKih6uEYEJw=; b=j+R/OvzbEZtIhpUEhIGWc3q1bbZHYp0Ul+K4Dz37jhZz1+6vh8PCxAdE6dTmaGXtW6 AVnPLavEd7Syclorws2JcUeO0Ym2q9+9XlivFihN3LffQaeuDEQZcQuLS3PhI8c3e0M8 H5d8biejz0cHioAeGCZa0kcBFxN6ksKnK8+XWSKEeS/l4Cqv9N4V7/f6qbhg629nMOnw rEOKgkL+i552j3dW2PRr0/3H69bdD2k/vTwnLDG49dNpkqLKW+ac3A6SNOchhs6cCtVK MXNTUs9RN9Ubp8B9PbOMfDTxeUqgEOhqONELTgmT+axiBQMnvZvssNO2OpyaF6kTEi/y r7Kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rMoBmnl3ZpBTv1UmtiTdiuto4NAuEX1ahKih6uEYEJw=; b=5dyBaKsu0MYfAYICVh/9ljA9TidTryulC0zAlKibiN4Jtv/iZd2vtecXdUO1bZFb4s cLSWIjqUEo1AJzzhzzZrzJV5uIOnqX4sIrwTWuhpuMau7rinA9gSe4f8heCMZECpUnSo oeff1Zl1X3c+n0LilhRkBNU1mTtxg9WkGd96bwDqS2c6ASgDhg2j++zXIHc6g28buszI 1gF2e0S2EX2y7Bxn/ygVFDuGG7MW3VGpKxcLrCVjXwv/W7wVk8MkF0YOXk3/H9Z5rram fllaNCc49P42kmpOIxDYcaE9F8dhjMbPl1nfg0dVLi4mMWnFASxobpWgtRsncWmZkZ4i 9gsg== X-Gm-Message-State: AJIora8gcIF0U8o3ZWD8XBZ7AIqgPoi+XEI9jDImLyIPHwzp+CS5fTD1 w5UUc7/KbrcdSSKm5a3CTfXFDeF9ylUWtw== X-Google-Smtp-Source: AGRyM1vwWKS94qRtIYCQT74pZ5Yf4pcr8nEvoMGSizTcpXdveRMSImguFS8MGQrIxdv0ZUQ8RxYMAg== X-Received: by 2002:a05:6402:26c3:b0:43a:a846:b2c1 with SMTP id x3-20020a05640226c300b0043aa846b2c1mr45920791edd.133.1658252599786; Tue, 19 Jul 2022 10:43:19 -0700 (PDT) From: Oleksandr Tyshchenko To: xen-devel@lists.xenproject.org Cc: Oleksandr Andrushchenko , =?utf-8?q?Ro?= =?utf-8?q?ger_Pau_Monn=C3=A9?= , Andrew Cooper , George Dunlap , Jan Beulich , Julien Grall , Stefano Stabellini , Wei Liu Subject: [PATCH V7 09/11] vpci: add initial support for virtual PCI bus topology Date: Tue, 19 Jul 2022 20:42:51 +0300 Message-Id: <20220719174253.541965-10-olekstysh@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220719174253.541965-1-olekstysh@gmail.com> References: <20220719174253.541965-1-olekstysh@gmail.com> MIME-Version: 1.0 From: Oleksandr Andrushchenko Assign SBDF to the PCI devices being passed through with bus 0. The resulting topology is where PCIe devices reside on the bus 0 of the root complex itself (embedded endpoints). This implementation is limited to 32 devices which are allowed on a single PCI bus. Please note, that at the moment only function 0 of a multifunction device can be passed through. Signed-off-by: Oleksandr Andrushchenko --- Since v6: - re-work wrt new locking scheme - OT: add ASSERT(pcidevs_write_locked()); to add_virtual_device() Since v5: - s/vpci_add_virtual_device/add_virtual_device and make it static - call add_virtual_device from vpci_assign_device and do not use REGISTER_VPCI_INIT machinery - add pcidevs_locked ASSERT - use DECLARE_BITMAP for vpci_dev_assigned_map Since v4: - moved and re-worked guest sbdf initializers - s/set_bit/__set_bit - s/clear_bit/__clear_bit - minor comment fix s/Virtual/Guest/ - added VPCI_MAX_VIRT_DEV constant (PCI_SLOT(~0) + 1) which will be used later for counting the number of MMIO handlers required for a guest (Julien) Since v3: - make use of VPCI_INIT - moved all new code to vpci.c which belongs to it - changed open-coded 31 to PCI_SLOT(~0) - added comments and code to reject multifunction devices with functions other than 0 - updated comment about vpci_dev_next and made it unsigned int - implement roll back in case of error while assigning/deassigning devices - s/dom%pd/%pd Since v2: - remove casts that are (a) malformed and (b) unnecessary - add new line for better readability - remove CONFIG_HAS_VPCI_GUEST_SUPPORT ifdef's as the relevant vPCI functions are now completely gated with this config - gate common code with CONFIG_HAS_VPCI_GUEST_SUPPORT New in v2 --- xen/drivers/vpci/vpci.c | 70 ++++++++++++++++++++++++++++++++++++++++- xen/include/xen/sched.h | 8 +++++ xen/include/xen/vpci.h | 11 +++++++ 3 files changed, 88 insertions(+), 1 deletion(-) diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c index f683346285..d4601ecf9b 100644 --- a/xen/drivers/vpci/vpci.c +++ b/xen/drivers/vpci/vpci.c @@ -84,6 +84,9 @@ int vpci_add_handlers(struct pci_dev *pdev) INIT_LIST_HEAD(&pdev->vpci->handlers); spin_lock_init(&pdev->vpci->lock); +#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT + pdev->vpci->guest_sbdf.sbdf = ~0; +#endif for ( i = 0; i < NUM_VPCI_INIT; i++ ) { @@ -99,6 +102,62 @@ int vpci_add_handlers(struct pci_dev *pdev) } #ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT +static int add_virtual_device(struct pci_dev *pdev) +{ + struct domain *d = pdev->domain; + pci_sbdf_t sbdf = { 0 }; + unsigned long new_dev_number; + + if ( is_hardware_domain(d) ) + return 0; + + ASSERT(pcidevs_write_locked()); + + /* + * Each PCI bus supports 32 devices/slots at max or up to 256 when + * there are multi-function ones which are not yet supported. + */ + if ( pdev->info.is_extfn ) + { + gdprintk(XENLOG_ERR, "%pp: only function 0 passthrough supported\n", + &pdev->sbdf); + return -EOPNOTSUPP; + } + + new_dev_number = find_first_zero_bit(d->vpci_dev_assigned_map, + VPCI_MAX_VIRT_DEV); + if ( new_dev_number >= VPCI_MAX_VIRT_DEV ) + return -ENOSPC; + + __set_bit(new_dev_number, &d->vpci_dev_assigned_map); + + /* + * Both segment and bus number are 0: + * - we emulate a single host bridge for the guest, e.g. segment 0 + * - with bus 0 the virtual devices are seen as embedded + * endpoints behind the root complex + * + * TODO: add support for multi-function devices. + */ + sbdf.devfn = PCI_DEVFN(new_dev_number, 0); + pdev->vpci->guest_sbdf = sbdf; + + return 0; + +} + +static void vpci_remove_virtual_device(const struct pci_dev *pdev) +{ + ASSERT(pcidevs_write_locked()); + + if ( pdev->vpci ) + { + __clear_bit(pdev->vpci->guest_sbdf.dev, + &pdev->domain->vpci_dev_assigned_map); + pdev->vpci->guest_sbdf.sbdf = ~0; + } +} + /* Notify vPCI that device is assigned to guest. */ int vpci_assign_device(struct pci_dev *pdev) { @@ -111,8 +170,16 @@ int vpci_assign_device(struct pci_dev *pdev) rc = vpci_add_handlers(pdev); if ( rc ) - vpci_deassign_device(pdev); + goto fail; + + rc = add_virtual_device(pdev); + if ( rc ) + goto fail; + + return 0; + fail: + vpci_deassign_device(pdev); return rc; } @@ -124,6 +191,7 @@ void vpci_deassign_device(struct pci_dev *pdev) if ( !has_vpci(pdev->domain) ) return; + vpci_remove_virtual_device(pdev); vpci_remove_device(pdev); } #endif /* CONFIG_HAS_VPCI_GUEST_SUPPORT */ diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index b9515eb497..a2848a5740 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -457,6 +457,14 @@ struct domain #ifdef CONFIG_HAS_PCI struct list_head pdev_list; +#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT + /* + * The bitmap which shows which device numbers are already used by the + * virtual PCI bus topology and is used to assign a unique SBDF to the + * next passed through virtual PCI device. + */ + DECLARE_BITMAP(vpci_dev_assigned_map, VPCI_MAX_VIRT_DEV); +#endif #endif #ifdef CONFIG_HAS_PASSTHROUGH diff --git a/xen/include/xen/vpci.h b/xen/include/xen/vpci.h index 1010f68c28..cc14b0086d 100644 --- a/xen/include/xen/vpci.h +++ b/xen/include/xen/vpci.h @@ -21,6 +21,13 @@ typedef int vpci_register_init_t(struct pci_dev *dev); #define VPCI_ECAM_BDF(addr) (((addr) & 0x0ffff000) >> 12) +/* + * Maximum number of devices supported by the virtual bus topology: + * each PCI bus supports 32 devices/slots at max or up to 256 when + * there are multi-function ones which are not yet supported. + */ +#define VPCI_MAX_VIRT_DEV (PCI_SLOT(~0) + 1) + #define REGISTER_VPCI_INIT(x, p) \ static vpci_register_init_t *const x##_entry \ __used_section(".data.vpci." p) = x @@ -145,6 +152,10 @@ struct vpci { struct vpci_arch_msix_entry arch; } entries[]; } *msix; +#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT + /* Guest SBDF of the device. */ + pci_sbdf_t guest_sbdf; +#endif #endif };