From patchwork Fri Feb 4 06:34:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Andrushchenko X-Patchwork-Id: 12734822 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 E0AF8C433F5 for ; Fri, 4 Feb 2022 06:35:29 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.265014.458370 (Exim 4.92) (envelope-from ) id 1nFsBh-0002hl-QP; Fri, 04 Feb 2022 06:35:17 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 265014.458370; Fri, 04 Feb 2022 06:35:17 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nFsBh-0002dg-El; Fri, 04 Feb 2022 06:35:17 +0000 Received: by outflank-mailman (input) for mailman id 265014; Fri, 04 Feb 2022 06:35:15 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nFsBf-0008DX-6C for xen-devel@lists.xenproject.org; Fri, 04 Feb 2022 06:35:15 +0000 Received: from mail-lf1-x130.google.com (mail-lf1-x130.google.com [2a00:1450:4864:20::130]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 9c0d2cc9-8584-11ec-8eb8-a37418f5ba1a; Fri, 04 Feb 2022 07:35:14 +0100 (CET) Received: by mail-lf1-x130.google.com with SMTP id o12so10664148lfg.12 for ; Thu, 03 Feb 2022 22:35:14 -0800 (PST) Received: from a2klaptop.localdomain ([185.199.97.5]) by smtp.gmail.com with ESMTPSA id f34sm163027lfv.165.2022.02.03.22.35.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Feb 2022 22:35:13 -0800 (PST) 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: 9c0d2cc9-8584-11ec-8eb8-a37418f5ba1a 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=tGFLOQCwkEQFlI9mFVvLvlv0pMnFdRny8N7SLfH9TJA=; b=YlgiD5lGb3evZ6RR1LePZhPhqzkgUVHIPb2Gy3O72gERgeDAmwDTYaB0XUarTQgsD8 pmdw7nrr7tOpf/VkdnbF851kb5Y8xpkUCSOphdAW69ua0+sdexi8ht29J6xt3629QdYw 8q421az1QnqIpTccWIu2jw9mRqZwIRJJQr9fjZjEvRHqTXgN99wxLu6k7zzlJ+iZexcK j131pVe1Bn0fM1phTaY1dA0B3H4DUjCi07cAHQi7H+H/6xGbYmNtrY/+dguki/2iv26P ps40BdLcc/ktXwgv/LnZ8VTYgZaZEO5Ys52gDX5rQ7GrNIjDR46fhSUVc4ThlvEPF0Vf kRFw== 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=tGFLOQCwkEQFlI9mFVvLvlv0pMnFdRny8N7SLfH9TJA=; b=3OSLR+PccHK9fCyIlslFJKh+x68f924fQVGXqIcwpFy68BovlCqqaRP9jKCunkKBna zw7Qok2HaYc3glIJ3iwYzRt+LV8XZwz1waeFrsFvxuD1f+eO0/Kd0EtgDbZmkdT5jkOf RwwWeEnBHB2jRm9qqlsNqB+rBDmYvE1IsODGRTbz+DDFD2/V4iRC+HXnJ6mz+wBXfnWS WzYO822evOxIbpjB2ZlacN44+dYukA0I0b8sWkxxoDhkf8l70WlRyn6j+yApRuMupTIc knl1hqKHhV55AQdpsCP5fHHxNAkLfmA6X/u6pLK1WKvjI5gHoA2PuQ/YN/JEKFndbbRS Ztjw== X-Gm-Message-State: AOAM530G2eU6sZ2vjGp6aIC62W9pCotfYBWy9qe2s03BqwTjMU+MqpBB wT3KG0hBdaK9Btd7cNgv+sHlSD17jgo= X-Google-Smtp-Source: ABdhPJwPzBAmRPwkr5ocrvbHVI7IaKNMChAL/CL0c1126BAXRRe8+v+tzkGTEQ3jLHc1eLnLZCqIZg== X-Received: by 2002:a05:6512:683:: with SMTP id t3mr1289026lfe.61.1643956513698; Thu, 03 Feb 2022 22:35:13 -0800 (PST) From: Oleksandr Andrushchenko To: xen-devel@lists.xenproject.org Cc: julien@xen.org, sstabellini@kernel.org, oleksandr_tyshchenko@epam.com, volodymyr_babchuk@epam.com, artem_mygaiev@epam.com, roger.pau@citrix.com, jbeulich@suse.com, andrew.cooper3@citrix.com, george.dunlap@citrix.com, paul@xen.org, bertrand.marquis@arm.com, rahul.singh@arm.com, Oleksandr Andrushchenko Subject: [PATCH v6 11/13] vpci: add initial support for virtual PCI bus topology Date: Fri, 4 Feb 2022 08:34:57 +0200 Message-Id: <20220204063459.680961-12-andr2000@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220204063459.680961-1-andr2000@gmail.com> References: <20220204063459.680961-1-andr2000@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 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 | 74 +++++++++++++++++++++++++++++++++++++++-- xen/include/xen/sched.h | 8 +++++ xen/include/xen/vpci.h | 11 ++++++ 3 files changed, 91 insertions(+), 2 deletions(-) diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c index 3177f13c1c22..7d422d11f83d 100644 --- a/xen/drivers/vpci/vpci.c +++ b/xen/drivers/vpci/vpci.c @@ -89,6 +89,9 @@ int vpci_add_handlers(struct pci_dev *pdev) return -ENOMEM; INIT_LIST_HEAD(&vpci->handlers); +#ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT + vpci->guest_sbdf.sbdf = ~0; +#endif spin_lock(&pdev->vpci_lock); pdev->vpci = vpci; @@ -114,6 +117,57 @@ 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_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(struct domain *d, + const struct pci_dev *pdev) +{ + __clear_bit(pdev->vpci->guest_sbdf.dev, &d->vpci_dev_assigned_map); + pdev->vpci->guest_sbdf.sbdf = ~0; +} + /* Notify vPCI that device is assigned to guest. */ int vpci_assign_device(struct domain *d, struct pci_dev *pdev) { @@ -124,8 +178,16 @@ int vpci_assign_device(struct domain *d, struct pci_dev *pdev) rc = vpci_add_handlers(pdev); if ( rc ) - vpci_deassign_device(d, pdev); + goto fail; + + rc = add_virtual_device(pdev); + if ( rc ) + goto fail; + return 0; + + fail: + vpci_deassign_device(d, pdev); return rc; } @@ -135,7 +197,15 @@ void vpci_deassign_device(struct domain *d, struct pci_dev *pdev) if ( !has_vpci(d) ) return; - vpci_remove_device(pdev); + spin_lock(&pdev->vpci_lock); + if ( !pdev->vpci ) + goto done; + + vpci_remove_virtual_device(d, pdev); + vpci_remove_device_locked(pdev); + + done: + spin_unlock(&pdev->vpci_lock); } #endif /* CONFIG_HAS_VPCI_GUEST_SUPPORT */ diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index 37f78cc4c4c9..3c25e265eaa8 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -444,6 +444,14 @@ 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 f1f49db959c7..1f04d34a2369 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 @@ -140,6 +147,10 @@ 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 };