From patchwork Sat Oct 15 15:34:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksandr Tyshchenko X-Patchwork-Id: 13007678 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 2112AC4332F for ; Sat, 15 Oct 2022 15:34:57 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.423497.670189 (Exim 4.92) (envelope-from ) id 1ojjBR-0004Sf-Hp; Sat, 15 Oct 2022 15:34:41 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 423497.670189; Sat, 15 Oct 2022 15:34:41 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ojjBR-0004SY-ER; Sat, 15 Oct 2022 15:34:41 +0000 Received: by outflank-mailman (input) for mailman id 423497; Sat, 15 Oct 2022 15:34:41 +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 1ojjBR-0004SS-1B for xen-devel@lists.xenproject.org; Sat, 15 Oct 2022 15:34:41 +0000 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [2a00:1450:4864:20::234]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id e1fa5463-4c9e-11ed-91b4-6bf2151ebd3b; Sat, 15 Oct 2022 17:34:39 +0200 (CEST) Received: by mail-lj1-x234.google.com with SMTP id h8so9230949lja.11 for ; Sat, 15 Oct 2022 08:34:39 -0700 (PDT) Received: from otyshchenko.router ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id i11-20020a0565123e0b00b00497a3e2a191sm773548lfv.112.2022.10.15.08.34.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 15 Oct 2022 08:34:38 -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: e1fa5463-4c9e-11ed-91b4-6bf2151ebd3b DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=ihOcqD/n8ZbX79lkXyTkddNqF22IgCuKxZEVGwB7Rsg=; b=WxtdSw3RVuokIk3VH0NlorLEv9hGbzMu1BXjJPFPg6tTUBAUACrJhaEons33ymTpay fsFTwfQbxQXLaSloPF8amM8JbNWOvBoQDVDLQP4T3JaPpsQauZT0geTwDcC7UyPymBz8 jnssWruJPe8g8dSeLpOrsbUEq2F3+WhotoQAeYxn0ytN33tQlg/cXg0w2K8+0o7dJ1lQ Fw9775uiwSMOsdy4oI1MLmDmKbuLHlD4bukfDsQASTZnmUa4nWgMHliZqbE9lx5bNeLn A/CtiP/rcDTETgtCh/oXjOsYxKX/0caViUXXDHU/1f9YJjOsTyTeiIU09NDlUTGoeKfL QZpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=ihOcqD/n8ZbX79lkXyTkddNqF22IgCuKxZEVGwB7Rsg=; b=1fneCdfk1S1eZpt16s9sg1dDijkEvtej51rhz31HMLNH0NDWr/RDjax5u52vaCQvMF ciMk2VXgpnACs1eoRTC4HDRKPbH/w/egE94IBfz4B1U3RWXlqZlIxDEgg0lp5AQ+bjPT Q33XbBLVl0cts65J4AkT0pklgTmLyXw2peM5SMblIFAvoFGfXhBojGrKJ6/h311wKy9o v6ddGBgFlRTKmx8PQLg/XsKBUkeLgcIyCz5WVi7vyNu6JhPX9rRwiSr9/YR1jb9FDga3 Q3uHodDkCieP58SCaf54AAsvLd7kz/3Tad6ii7raGttYZsoMEpQ1F61n/B8U2Fh6F17W lrdw== X-Gm-Message-State: ACrzQf3hU3zDYXvMHfkYdhfDX28HzzsqYdKN895XSVkSNI0aj59ly1LB aIFOrF6HPhL3VnI970cWh6WOgtRkC3BjHQ== X-Google-Smtp-Source: AMsMyM4cTx61Y6kV/OX5Wcl7kFX+mFhoVOm1PT3Oovb9gJ2D7Wkm7T2AtGUh6I1wmhv3Ee7UT1Dz3w== X-Received: by 2002:a05:651c:158f:b0:26b:dd9c:dca5 with SMTP id h15-20020a05651c158f00b0026bdd9cdca5mr1153297ljq.400.1665848078845; Sat, 15 Oct 2022 08:34:38 -0700 (PDT) From: Oleksandr Tyshchenko To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Oleksandr Tyshchenko , Stefano Stabellini , Juergen Gross Subject: [PATCH V2] xen/virtio: Handle PCI devices which Host controller is described in DT Date: Sat, 15 Oct 2022 18:34:09 +0300 Message-Id: <20221015153409.918775-1-olekstysh@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 From: Oleksandr Tyshchenko Use the same "xen-grant-dma" device concept for the PCI devices behind device-tree based PCI Host controller, but with one modification. Unlike for platform devices, we cannot use generic IOMMU bindings (iommus property), as we need to support more flexible configuration. The problem is that PCI devices under the single PCI Host controller may have the backends running in different Xen domains and thus have different endpoints ID (backend domains ID). So use generic PCI-IOMMU bindings instead (iommu-map/iommu-map-mask properties) which allows us to describe relationship between PCI devices and backend domains ID properly. Signed-off-by: Oleksandr Tyshchenko --- Slightly RFC. This is needed to support Xen grant mappings for virtio-pci devices on Arm at some point in the future. The Xen toolstack side is not completely ready yet. Here, for PCI devices we use more flexible way to pass backend domid to the guest than for platform devices. Changes V1 -> V2: - update commit description - rebase - rework to use generic PCI-IOMMU bindings instead of generic IOMMU bindings Previous discussion is at: https://lore.kernel.org/xen-devel/20221006174804.2003029-1-olekstysh@gmail.com/ Based on: https://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git/log/?h=for-linus-6.1 --- drivers/xen/grant-dma-ops.c | 87 ++++++++++++++++++++++++++++++++----- 1 file changed, 76 insertions(+), 11 deletions(-) diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c index daa525df7bdc..b79d9d6ce154 100644 --- a/drivers/xen/grant-dma-ops.c +++ b/drivers/xen/grant-dma-ops.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -292,12 +293,55 @@ static const struct dma_map_ops xen_grant_dma_ops = { .dma_supported = xen_grant_dma_supported, }; +static struct device_node *xen_dt_get_pci_host_node(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + struct pci_bus *bus = pdev->bus; + + /* Walk up to the root bus to look for PCI Host controller */ + while (!pci_is_root_bus(bus)) + bus = bus->parent; + + return of_node_get(bus->bridge->parent->of_node); +} + +static struct device_node *xen_dt_get_node(struct device *dev) +{ + if (dev_is_pci(dev)) + return xen_dt_get_pci_host_node(dev); + + return of_node_get(dev->of_node); +} + +static int xen_dt_map_id(struct device *dev, struct device_node **iommu_np, + u32 *sid) +{ + struct pci_dev *pdev = to_pci_dev(dev); + u32 rid = PCI_DEVID(pdev->bus->number, pdev->devfn); + struct device_node *host_np; + int ret; + + host_np = xen_dt_get_pci_host_node(dev); + if (!host_np) + return -ENODEV; + + ret = of_map_id(host_np, rid, "iommu-map", "iommu-map-mask", iommu_np, sid); + of_node_put(host_np); + + return ret; +} + static bool xen_is_dt_grant_dma_device(struct device *dev) { - struct device_node *iommu_np; + struct device_node *iommu_np = NULL; bool has_iommu; - iommu_np = of_parse_phandle(dev->of_node, "iommus", 0); + if (dev_is_pci(dev)) { + if (xen_dt_map_id(dev, &iommu_np, NULL)) + return false; + } else + iommu_np = of_parse_phandle(dev->of_node, "iommus", 0); + has_iommu = iommu_np && of_device_is_compatible(iommu_np, "xen,grant-dma"); of_node_put(iommu_np); @@ -307,9 +351,17 @@ static bool xen_is_dt_grant_dma_device(struct device *dev) bool xen_is_grant_dma_device(struct device *dev) { + struct device_node *np; + /* XXX Handle only DT devices for now */ - if (dev->of_node) - return xen_is_dt_grant_dma_device(dev); + np = xen_dt_get_node(dev); + if (np) { + bool ret; + + ret = xen_is_dt_grant_dma_device(dev); + of_node_put(np); + return ret; + } return false; } @@ -325,12 +377,19 @@ bool xen_virtio_mem_acc(struct virtio_device *dev) static int xen_dt_grant_init_backend_domid(struct device *dev, struct xen_grant_dma_data *data) { - struct of_phandle_args iommu_spec; + struct of_phandle_args iommu_spec = { .args_count = 1 }; - if (of_parse_phandle_with_args(dev->of_node, "iommus", "#iommu-cells", - 0, &iommu_spec)) { - dev_err(dev, "Cannot parse iommus property\n"); - return -ESRCH; + if (dev_is_pci(dev)) { + if (xen_dt_map_id(dev, &iommu_spec.np, iommu_spec.args)) { + dev_err(dev, "Cannot translate ID\n"); + return -ESRCH; + } + } else { + if (of_parse_phandle_with_args(dev->of_node, "iommus", "#iommu-cells", + 0, &iommu_spec)) { + dev_err(dev, "Cannot parse iommus property\n"); + return -ESRCH; + } } if (!of_device_is_compatible(iommu_spec.np, "xen,grant-dma") || @@ -354,6 +413,7 @@ static int xen_dt_grant_init_backend_domid(struct device *dev, void xen_grant_setup_dma_ops(struct device *dev) { struct xen_grant_dma_data *data; + struct device_node *np; data = find_xen_grant_dma_data(dev); if (data) { @@ -365,8 +425,13 @@ void xen_grant_setup_dma_ops(struct device *dev) if (!data) goto err; - if (dev->of_node) { - if (xen_dt_grant_init_backend_domid(dev, data)) + np = xen_dt_get_node(dev); + if (np) { + int ret; + + ret = xen_dt_grant_init_backend_domid(dev, data); + of_node_put(np); + if (ret) goto err; } else if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT)) { dev_info(dev, "Using dom0 as backend\n");