From patchwork Sun Jan 3 08:24:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Romanovsky X-Patchwork-Id: 11995549 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ADBE5C4332B for ; Sun, 3 Jan 2021 08:25:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DEDF2080D for ; Sun, 3 Jan 2021 08:25:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726480AbhACIZb (ORCPT ); Sun, 3 Jan 2021 03:25:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:43506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725829AbhACIZb (ORCPT ); Sun, 3 Jan 2021 03:25:31 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6250420829; Sun, 3 Jan 2021 08:24:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1609662290; bh=LzBvEeM3F5CHvobstbPaXR0JOAI/eEhyh1tqZzNDyZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=goYEc9z3qvubzKVXoNyL1ceuR74zXrGLh+8VODzmCH14Dh7CcNGQnoi7vny9HvDcr oqWxxEKiKl1x6iZfqTfD3p0YC0EIVxp9ssmWHuOtAgs+roMxrvXCAsz9can5zjFX2I 4IoZAUGsZEYi95lMp1EKn+cgOUT5vJyvKo0AFSZFh8z7DpHYzeZPrmfuXWG2NoTcd+ sfS6pXQrAeVbJ/rArpzJg/K4sPIiYPSSoIvI9QCggLM+KrpvxLiAJXsEAJgpn5JnIQ 292afVpXtEVXkEqpNRk0konAoUhxvDyCaMVIe0TNMsWCDE9X7Zx7vT87Qp3LXyzVz3 m0XKc6t8SVM1A== From: Leon Romanovsky To: Bjorn Helgaas , Saeed Mahameed Cc: Leon Romanovsky , Jason Gunthorpe , Jakub Kicinski , linux-pci@vger.kernel.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH mlx5-next 1/4] PCI: Configure number of MSI-X vectors for SR-IOV VFs Date: Sun, 3 Jan 2021 10:24:37 +0200 Message-Id: <20210103082440.34994-2-leon@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210103082440.34994-1-leon@kernel.org> References: <20210103082440.34994-1-leon@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Leon Romanovsky This function is applicable for SR-IOV VFs because such devices allocate their MSI-X table before they will run on the targeted hardware and they can't guess the right amount of vectors. Signed-off-by: Leon Romanovsky --- Documentation/ABI/testing/sysfs-bus-pci | 16 +++++++ drivers/pci/iov.c | 57 +++++++++++++++++++++++++ drivers/pci/msi.c | 30 +++++++++++++ drivers/pci/pci-sysfs.c | 1 + drivers/pci/pci.h | 1 + include/linux/pci.h | 8 ++++ 6 files changed, 113 insertions(+) -- 2.29.2 diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index 25c9c39770c6..30720a9e1386 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -375,3 +375,19 @@ Description: The value comes from the PCI kernel device state and can be one of: "unknown", "error", "D0", D1", "D2", "D3hot", "D3cold". The file is read only. + +What: /sys/bus/pci/devices/.../vf_msix_vec +Date: December 2020 +Contact: Leon Romanovsky +Description: + This file is associated with the SR-IOV VFs. It allows overwrite + the amount of MSI-X vectors for that VF. This is needed to optimize + performance of newly bounded devices by allocating the number of + vectors based on the internal knowledge of targeted VM. + + The values accepted are: + * > 0 - this will be number reported by the PCI VF's PCIe MSI-X capability. + * < 0 - not valid + * = 0 - will reset to the device default value + + The file is writable if no driver is bounded. diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 4afd4ee4f7f0..0f8c570361fc 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -31,6 +31,7 @@ int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id) return (dev->devfn + dev->sriov->offset + dev->sriov->stride * vf_id) & 0xff; } +EXPORT_SYMBOL(pci_iov_virtfn_devfn); /* * Per SR-IOV spec sec 3.3.10 and 3.3.11, First VF Offset and VF Stride may @@ -426,6 +427,62 @@ const struct attribute_group sriov_dev_attr_group = { .is_visible = sriov_attrs_are_visible, }; +#ifdef CONFIG_PCI_MSI +static ssize_t vf_msix_vec_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pci_dev *pdev = to_pci_dev(dev); + int numb = pci_msix_vec_count(pdev); + + if (numb < 0) + return numb; + + return sprintf(buf, "%d\n", numb); +} + +static ssize_t vf_msix_vec_store(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t count) +{ + struct pci_dev *vf_dev = to_pci_dev(dev); + int val, ret; + + ret = kstrtoint(buf, 0, &val); + if (ret) + return ret; + + ret = pci_set_msix_vec_count(vf_dev, val); + if (ret) + return ret; + + return count; +} +static DEVICE_ATTR_RW(vf_msix_vec); +#endif + +static struct attribute *sriov_vf_dev_attrs[] = { +#ifdef CONFIG_PCI_MSI + &dev_attr_vf_msix_vec.attr, +#endif + NULL, +}; + +static umode_t sriov_vf_attrs_are_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct device *dev = kobj_to_dev(kobj); + + if (dev_is_pf(dev)) + return 0; + + return a->mode; +} + +const struct attribute_group sriov_vf_dev_attr_group = { + .attrs = sriov_vf_dev_attrs, + .is_visible = sriov_vf_attrs_are_visible, +}; + int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs) { return 0; diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 3162f88fe940..0bcd705487d9 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -991,6 +991,36 @@ int pci_msix_vec_count(struct pci_dev *dev) } EXPORT_SYMBOL(pci_msix_vec_count); +/** + * pci_set_msix_vec_count - change the reported number of MSI-X vectors. + * This function is applicable for SR-IOV VFs because such devices allocate + * their MSI-X table before they will run on the targeted hardware and they + * can't guess the right amount of vectors. + * @dev: VF device that is going to be changed. + * @numb: amount of MSI-X vectors. + **/ +int pci_set_msix_vec_count(struct pci_dev *dev, int numb) +{ + struct pci_dev *pdev = pci_physfn(dev); + + if (!dev->msix_cap || !pdev->msix_cap) + return -EINVAL; + + if (dev->driver || !pdev->driver || + !pdev->driver->sriov_set_msix_vec_count) + return -EOPNOTSUPP; + + if (numb < 0) + /* + * We don't support negative numbers for now, + * but maybe in the future it will make sense. + */ + return -EINVAL; + + return pdev->driver->sriov_set_msix_vec_count(dev, numb); +} +EXPORT_SYMBOL(pci_set_msix_vec_count); + static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec, struct irq_affinity *affd, int flags) { diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index fb072f4b3176..0af2222643c2 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -1557,6 +1557,7 @@ static const struct attribute_group *pci_dev_attr_groups[] = { &pci_dev_hp_attr_group, #ifdef CONFIG_PCI_IOV &sriov_dev_attr_group, + &sriov_vf_dev_attr_group, #endif &pci_bridge_attr_group, &pcie_dev_attr_group, diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 5c59365092fa..46396a5da2d9 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -502,6 +502,7 @@ resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno); void pci_restore_iov_state(struct pci_dev *dev); int pci_iov_bus_range(struct pci_bus *bus); extern const struct attribute_group sriov_dev_attr_group; +extern const struct attribute_group sriov_vf_dev_attr_group; #else static inline int pci_iov_init(struct pci_dev *dev) { diff --git a/include/linux/pci.h b/include/linux/pci.h index b32126d26997..1acba40a1b1b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -856,6 +856,8 @@ struct module; * e.g. drivers/net/e100.c. * @sriov_configure: Optional driver callback to allow configuration of * number of VFs to enable via sysfs "sriov_numvfs" file. + * @sriov_set_msix_vec_count: Driver callback to change number of MSI-X vectors + * exposed by the sysfs "vf_msix_vec" entry. * @err_handler: See Documentation/PCI/pci-error-recovery.rst * @groups: Sysfs attribute groups. * @driver: Driver model structure. @@ -871,6 +873,7 @@ struct pci_driver { int (*resume)(struct pci_dev *dev); /* Device woken up */ void (*shutdown)(struct pci_dev *dev); int (*sriov_configure)(struct pci_dev *dev, int num_vfs); /* On PF */ + int (*sriov_set_msix_vec_count)(struct pci_dev *vf, int msix_vec_count); /* On PF */ const struct pci_error_handlers *err_handler; const struct attribute_group **groups; struct device_driver driver; @@ -1464,6 +1467,7 @@ struct msix_entry { int pci_msi_vec_count(struct pci_dev *dev); void pci_disable_msi(struct pci_dev *dev); int pci_msix_vec_count(struct pci_dev *dev); +int pci_set_msix_vec_count(struct pci_dev *dev, int numb); void pci_disable_msix(struct pci_dev *dev); void pci_restore_msi_state(struct pci_dev *dev); int pci_msi_enabled(void); @@ -2402,6 +2406,10 @@ static inline bool pci_is_thunderbolt_attached(struct pci_dev *pdev) void pci_uevent_ers(struct pci_dev *pdev, enum pci_ers_result err_type); #endif +#ifdef CONFIG_PCI_IOV +int pci_iov_virtfn_devfn(struct pci_dev *dev, int vf_id); +#endif + /* Provide the legacy pci_dma_* API */ #include