From nobody Mon Feb 9 12:25:45 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=none dis=none) header.from=gmail.com ARC-Seal: i=1; a=rsa-sha256; t=1653944468; cv=none; d=zohomail.com; s=zohoarc; b=MLTtph3mW+YXQ3folOStehGskv9TXfq2bHEhX/w0J+ctD+PfJ+KBHLR5kNeox+ECsuKIcQNdt54kRZB4JrgSuNC2PQ9VlnO2vc9HAOROsZVvifzTwAOdjfCYAg/vSNDcjjq+No1Msr3mmJXOh0eNg77WUN1bWsSx4r9WkN5gWQc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1653944468; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=uQ1JH7AWAJHsRRYFQY27acyYSyJWPZ/cZSwuKE03m9M=; b=LoAIHox4Y4INyRAS0OdaiEm5zOsfqS3rdpdJrpcrx1bpu3bBNl8U+6JGumrjDSUH+d2o8PQnUnoAxobEIZC4oUVJXG//JdDnctzrUWUsv54mLtPnk6vtnWsR++y/69HjCS3P1/IA6MubwAXG+14CjNgFEsB3h9atZ4UA817cEfE= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1653944468709693.0873689698052; Mon, 30 May 2022 14:01:08 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.338750.563624 (Exim 4.92) (envelope-from ) id 1nvmVB-0000cx-37; Mon, 30 May 2022 21:00:37 +0000 Received: by outflank-mailman (output) from mailman id 338750.563624; Mon, 30 May 2022 21:00:37 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nvmVA-0000c0-Qn; Mon, 30 May 2022 21:00:36 +0000 Received: by outflank-mailman (input) for mailman id 338750; Mon, 30 May 2022 21:00:35 +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 1nvmV8-0007Ks-Sa for xen-devel@lists.xenproject.org; Mon, 30 May 2022 21:00:35 +0000 Received: from mail-lj1-x22c.google.com (mail-lj1-x22c.google.com [2a00:1450:4864:20::22c]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 8c2e20ae-e05b-11ec-bd2c-47488cf2e6aa; Mon, 30 May 2022 23:00:34 +0200 (CEST) Received: by mail-lj1-x22c.google.com with SMTP id q1so12744266ljb.5 for ; Mon, 30 May 2022 14:00:34 -0700 (PDT) Received: from otyshchenko.router ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id k21-20020a2ea275000000b0025550e2693asm581541ljm.38.2022.05.30.14.00.32 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 30 May 2022 14:00:33 -0700 (PDT) X-Outflank-Mailman: Message body and most headers restored to incoming version 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: 8c2e20ae-e05b-11ec-bd2c-47488cf2e6aa 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; bh=uQ1JH7AWAJHsRRYFQY27acyYSyJWPZ/cZSwuKE03m9M=; b=F3Dp/1RfYd/CNOWtpufTjQ5KG1C/SjG2GTXBdmAnmkIZmIISp6swxVs8EtEn+CBphf bJoFFuN+PnP5FTSwKK7r/G8qOeglHY3GL5o10B5kKyNI3lbYT2QRFbJMxi4Am+JQI3ZN ehlzziC+FS40xWH5CO/plPfSgnEkPRbzN/ZpEuxVsyac3aY0NmGhhav6DE7ZZk3YYLiZ NIBnVA7VpoQLIsLbKcRgByxkCjJh6t4jRaz3uUTAJF0JG+Zo5N5/KlXzqzM6ILBj7ile v0bUG3G8bfZR3IgtGMst1ql3DwP8EUrB62vK7C0on5gaI+gMR/yHkjGBuGFC74oT++mK ISEw== 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; bh=uQ1JH7AWAJHsRRYFQY27acyYSyJWPZ/cZSwuKE03m9M=; b=NIcxBWdKKSECCFXSQTFd4gjYbWy+sMfBVSdTw/tzcrjWHqMf4BJPwdM2GW5hF+c3nl ffr7tse8JcNGebrxKF0ikt83oYe0IcOIdgHE4GrqkJvvlHeJOeAL8KFGvWsSteFMLPsp GLy81hW3ZRavb1vghqtdznneVwqIQRBaeBz6V9kto/zTnWRg5OMIKc1xhz3Oais2yqTi b4tZ2jbOZ7ZhKzs9cdVi5Mjac0RaG7LKx5t0E88ZOU0xXlfbDs7epaXcHPuY1KDgW8KS uFFpuTzOjD+/r6TOjg6Qj0R5q2FuJBzpKvhLZb28ClG/ZugGQ+0imyo01GtCSA08kOkI NxAg== X-Gm-Message-State: AOAM5325QvQmbUvE6mLvt+NgFOPWhlkM12621ih+NuxDTy0Ad0ht1ds9 Pj8SO/n0cjU2/J1am4zcqOiANTKrR0U= X-Google-Smtp-Source: ABdhPJwO1sx6nXB3yQvX6BxgfoZrQPM9WyfnZcUaKJhUw7Qhdh1gVI5p09PHodbZD/CPwbZDBCk3cg== X-Received: by 2002:a2e:b88d:0:b0:253:ee2a:6b70 with SMTP id r13-20020a2eb88d000000b00253ee2a6b70mr22917522ljp.247.1653944433394; Mon, 30 May 2022 14:00:33 -0700 (PDT) From: Oleksandr Tyshchenko To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Oleksandr Tyshchenko , Stefano Stabellini , Boris Ostrovsky , Juergen Gross , Julien Grall , "Michael S. Tsirkin" , Christoph Hellwig Subject: [PATCH V3 7/8] xen/grant-dma-ops: Retrieve the ID of backend's domain for DT devices Date: Tue, 31 May 2022 00:00:16 +0300 Message-Id: <1653944417-17168-8-git-send-email-olekstysh@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1653944417-17168-1-git-send-email-olekstysh@gmail.com> References: <1653944417-17168-1-git-send-email-olekstysh@gmail.com> X-ZohoMail-DKIM: pass (identity @gmail.com) X-ZM-MESSAGEID: 1653944469876100012 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Oleksandr Tyshchenko Use the presence of "iommus" property pointed to the IOMMU node with recently introduced "xen,grant-dma" compatible as a clear indicator of enabling Xen grant mappings scheme for that device and read the ID of Xen domain where the corresponding backend is running. The domid (domain ID) is used as an argument to the Xen grant mapping APIs. To avoid the deferred probe timeout which takes place after reusing generic IOMMU device tree bindings (because the IOMMU device never becomes available) enable recently introduced stub IOMMU driver by selecting XEN_GRANT_DMA_IOMMU. Also introduce xen_is_grant_dma_device() to check whether xen-grant DMA ops need to be set for a passed device. Remove the hardcoded domid 0 in xen_grant_setup_dma_ops(). Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini --- Changes RFC -> V1: - new patch, split required changes from commit: "[PATCH 4/6] virtio: Various updates to xen-virtio DMA ops layer" - update checks in xen_virtio_setup_dma_ops() to only support DT devices for now - remove the "virtio,mmio" check from xen_is_virtio_device() - remane everything according to the new naming scheme: s/virtio/grant_dma Changes V1 -> V2: - remove dev_is_pci() check in xen_grant_setup_dma_ops() - remove EXPORT_SYMBOL_GPL(xen_is_grant_dma_device); Changes V2 -> V3: - Stefano already gave his Reviewed-by, I dropped it due to the changes = (significant) - update commit description - reuse generic IOMMU device tree bindings, select XEN_GRANT_DMA_IOMMU to avoid the deferred probe timeout --- drivers/xen/Kconfig | 1 + drivers/xen/grant-dma-ops.c | 48 ++++++++++++++++++++++++++++++++++++++---= ---- include/xen/xen-ops.h | 5 +++++ 3 files changed, 47 insertions(+), 7 deletions(-) diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 35d20d9..bfd5f4f 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -347,6 +347,7 @@ config XEN_VIRTIO bool "Xen virtio support" depends on VIRTIO select XEN_GRANT_DMA_OPS + select XEN_GRANT_DMA_IOMMU if OF help Enable virtio support for running as Xen guest. Depending on the guest type this will require special support on the backend side diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c index 44659f4..6586152 100644 --- a/drivers/xen/grant-dma-ops.c +++ b/drivers/xen/grant-dma-ops.c @@ -55,11 +55,6 @@ static struct xen_grant_dma_data *find_xen_grant_dma_dat= a(struct device *dev) * Such a DMA address is formed by using the grant reference as a frame * number and setting the highest address bit (this bit is for the backend * to be able to distinguish it from e.g. a mmio address). - * - * Note that for now we hard wire dom0 to be the backend domain. In order - * to support any domain as backend we'd need to add a way to communicate - * the domid of this backend, e.g. via Xenstore, via the PCI-device's - * config space or DT/ACPI. */ static void *xen_grant_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, @@ -275,9 +270,26 @@ static const struct dma_map_ops xen_grant_dma_ops =3D { .dma_supported =3D xen_grant_dma_supported, }; =20 +bool xen_is_grant_dma_device(struct device *dev) +{ + struct device_node *iommu_np; + bool has_iommu; + + /* XXX Handle only DT devices for now */ + if (!dev->of_node) + return false; + + iommu_np =3D of_parse_phandle(dev->of_node, "iommus", 0); + has_iommu =3D iommu_np && of_device_is_compatible(iommu_np, "xen,grant-dm= a"); + of_node_put(iommu_np); + + return has_iommu; +} + void xen_grant_setup_dma_ops(struct device *dev) { struct xen_grant_dma_data *data; + struct of_phandle_args iommu_spec; =20 data =3D find_xen_grant_dma_data(dev); if (data) { @@ -285,12 +297,34 @@ void xen_grant_setup_dma_ops(struct device *dev) return; } =20 + /* XXX ACPI device unsupported for now */ + if (!dev->of_node) + goto err; + + if (of_parse_phandle_with_args(dev->of_node, "iommus", "#iommu-cells", + 0, &iommu_spec)) { + dev_err(dev, "Cannot parse iommus property\n"); + goto err; + } + + if (!of_device_is_compatible(iommu_spec.np, "xen,grant-dma") || + iommu_spec.args_count !=3D 1) { + dev_err(dev, "Incompatible IOMMU node\n"); + of_node_put(iommu_spec.np); + goto err; + } + + of_node_put(iommu_spec.np); + data =3D devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) goto err; =20 - /* XXX The dom0 is hardcoded as the backend domain for now */ - data->backend_domid =3D 0; + /* + * The endpoint ID here means the ID of the domain where the corresponding + * backend is running + */ + data->backend_domid =3D iommu_spec.args[0]; =20 if (xa_err(xa_store(&xen_grant_dma_devices, (unsigned long)dev, data, GFP_KERNEL))) { diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index 4f9fad5..62be9dc 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -223,10 +223,15 @@ static inline void xen_preemptible_hcall_end(void) { } =20 #ifdef CONFIG_XEN_GRANT_DMA_OPS void xen_grant_setup_dma_ops(struct device *dev); +bool xen_is_grant_dma_device(struct device *dev); #else static inline void xen_grant_setup_dma_ops(struct device *dev) { } +static inline bool xen_is_grant_dma_device(struct device *dev) +{ + return false; +} #endif /* CONFIG_XEN_GRANT_DMA_OPS */ =20 #endif /* INCLUDE_XEN_OPS_H */ --=20 2.7.4