From patchwork Wed Jun 15 16:12:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12882689 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCE17CCA488 for ; Wed, 15 Jun 2022 16:13:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234028AbiFOQNA (ORCPT ); Wed, 15 Jun 2022 12:13:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348685AbiFOQMx (ORCPT ); Wed, 15 Jun 2022 12:12:53 -0400 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95C9A6479; Wed, 15 Jun 2022 09:12:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:MIME-Version:References:In-Reply-To: Message-Id:Date:Cc:To:From:content-disposition; bh=X1Y+xHoeQH3UW63rjymiD/emNoqwBnemSVoIxTF9EbY=; b=iKgX6plSnGYTUQgEz3h2eQ8oq4 FGlAIFJWTusbVwsUGEKQv5w3YldIr+Zb7y9e5Tci57QG4okfn/WNYoSJSPedAWtRsJ317QnqZ3tYN B1fywGUu5iwDLF9GPEgBC7jVnfl/bzFg+cc/N6mZ6JQngmxQwJYFT1EsGSRC6XIG1doRvnySpVRU/ tzfXsXC/u1Ur26GJQGnmxT26Dpy7yBQ61LA/ooaFX1WIMUL63WFzcYKEzecykYtWm5V8bVzy+p78C Z+iMAawOzUWIvBjOXPztbfswoP+njdZ1jiGYb3TqxWthTb6w8cx/ik5VmwwPqeARrQ2tc76XIBIjc 0eUneuvg==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1o1VdO-0084iQ-Ox; Wed, 15 Jun 2022 10:12:47 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1o1VdJ-0004b4-QT; Wed, 15 Jun 2022 10:12:41 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Stephen Bates , Christoph Hellwig , Dan Williams , Jason Gunthorpe , =?utf-8?q?Christian_K=C3=B6nig?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni , Ralph Campbell , Logan Gunthorpe Date: Wed, 15 Jun 2022 10:12:33 -0600 Message-Id: <20220615161233.17527-22-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220615161233.17527-1-logang@deltatee.com> References: <20220615161233.17527-1-logang@deltatee.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, sbates@raithlin.com, hch@lst.de, jgg@ziepe.ca, christian.koenig@amd.com, ddutile@redhat.com, willy@infradead.org, daniel.vetter@ffwll.ch, jason@jlekstrand.net, dave.hansen@linux.intel.com, helgaas@kernel.org, dan.j.williams@intel.com, dave.b.minturn@intel.com, jianxin.xiong@intel.com, ira.weiny@intel.com, robin.murphy@arm.com, martin.oliveira@eideticom.com, ckulkarnilinux@gmail.com, jhubbard@nvidia.com, rcampbell@nvidia.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v7 21/21] nvme-pci: allow mmaping the CMB in userspace X-SA-Exim-Version: 4.2.1 (built Sat, 13 Feb 2021 17:57:42 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Allow userspace to obtain CMB memory by mmaping the controller's char device. The mmap call allocates and returns a hunk of CMB memory, (the offset is ignored) so userspace does not have control over the address within the CMB. A VMA allocated in this way will only be usable by drivers that set FOLL_PCI_P2PDMA when calling GUP. And inter-device support will be checked the first time the pages are mapped for DMA. Currently this is only supported by O_DIRECT to an PCI NVMe device or through the NVMe passthrough IOCTL. Signed-off-by: Logan Gunthorpe --- drivers/nvme/host/core.c | 35 +++++++++++++++++++++++++++++++---- drivers/nvme/host/nvme.h | 3 +++ drivers/nvme/host/pci.c | 23 +++++++++++++++++++++++ 3 files changed, 57 insertions(+), 4 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index d6e76f2dc293..23fe4b544bf1 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3166,6 +3166,7 @@ static int nvme_dev_open(struct inode *inode, struct file *file) { struct nvme_ctrl *ctrl = container_of(inode->i_cdev, struct nvme_ctrl, cdev); + int ret = -EINVAL; switch (ctrl->state) { case NVME_CTRL_LIVE: @@ -3175,13 +3176,25 @@ static int nvme_dev_open(struct inode *inode, struct file *file) } nvme_get_ctrl(ctrl); - if (!try_module_get(ctrl->ops->module)) { - nvme_put_ctrl(ctrl); - return -EINVAL; - } + if (!try_module_get(ctrl->ops->module)) + goto err_put_ctrl; file->private_data = ctrl; + + if (ctrl->ops->cdev_file_open) { + ret = ctrl->ops->cdev_file_open(ctrl, file); + if (ret) + goto err_put_mod; + } + return 0; + +err_put_mod: + module_put(ctrl->ops->module); +err_put_ctrl: + nvme_put_ctrl(ctrl); + return ret; + } static int nvme_dev_release(struct inode *inode, struct file *file) @@ -3189,11 +3202,24 @@ static int nvme_dev_release(struct inode *inode, struct file *file) struct nvme_ctrl *ctrl = container_of(inode->i_cdev, struct nvme_ctrl, cdev); + if (ctrl->ops->cdev_file_release) + ctrl->ops->cdev_file_release(file); + module_put(ctrl->ops->module); nvme_put_ctrl(ctrl); return 0; } +static int nvme_dev_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct nvme_ctrl *ctrl = file->private_data; + + if (!ctrl->ops->mmap_cmb) + return -ENODEV; + + return ctrl->ops->mmap_cmb(ctrl, vma); +} + static const struct file_operations nvme_dev_fops = { .owner = THIS_MODULE, .open = nvme_dev_open, @@ -3201,6 +3227,7 @@ static const struct file_operations nvme_dev_fops = { .unlocked_ioctl = nvme_dev_ioctl, .compat_ioctl = compat_ptr_ioctl, .uring_cmd = nvme_dev_uring_cmd, + .mmap = nvme_dev_mmap, }; static ssize_t nvme_sysfs_reset(struct device *dev, diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 957f79420cf3..44ff05d8e24d 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -503,6 +503,9 @@ struct nvme_ctrl_ops { void (*delete_ctrl)(struct nvme_ctrl *ctrl); int (*get_address)(struct nvme_ctrl *ctrl, char *buf, int size); bool (*supports_pci_p2pdma)(struct nvme_ctrl *ctrl); + int (*cdev_file_open)(struct nvme_ctrl *ctrl, struct file *file); + void (*cdev_file_release)(struct file *file); + int (*mmap_cmb)(struct nvme_ctrl *ctrl, struct vm_area_struct *vma); }; /* diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 52b52a7efa9a..8ef3752b7ddb 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -2972,6 +2972,26 @@ static bool nvme_pci_supports_pci_p2pdma(struct nvme_ctrl *ctrl) return dma_pci_p2pdma_supported(dev->dev); } +static int nvme_pci_cdev_file_open(struct nvme_ctrl *ctrl, struct file *file) +{ + struct pci_dev *pdev = to_pci_dev(to_nvme_dev(ctrl)->dev); + + return pci_p2pdma_file_open(pdev, file); +} + +static void nvme_pci_cdev_file_release(struct file *file) +{ + pci_p2pdma_file_release(file); +} + +static int nvme_pci_mmap_cmb(struct nvme_ctrl *ctrl, + struct vm_area_struct *vma) +{ + struct pci_dev *pdev = to_pci_dev(to_nvme_dev(ctrl)->dev); + + return pci_mmap_p2pmem(pdev, vma); +} + static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = { .name = "pcie", .module = THIS_MODULE, @@ -2983,6 +3003,9 @@ static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = { .submit_async_event = nvme_pci_submit_async_event, .get_address = nvme_pci_get_address, .supports_pci_p2pdma = nvme_pci_supports_pci_p2pdma, + .cdev_file_open = nvme_pci_cdev_file_open, + .cdev_file_release = nvme_pci_cdev_file_release, + .mmap_cmb = nvme_pci_mmap_cmb, }; static int nvme_dev_map(struct nvme_dev *dev)