vfio_pci.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved
 *
 * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
 *     Author: Alex Williamson <alex.williamson@redhat.com>
 *
 * Derived from original vfio:
 * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
 * Author: Tom Lyon, pugs@cisco.com
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/device.h>
#include <linux/eventfd.h>
#include <linux/file.h>
#include <linux/interrupt.h>
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/uaccess.h>

#include "vfio_pci_priv.h"

#define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
#define DRIVER_DESC     "VFIO PCI - User Level meta-driver"

static char ids[1024] __initdata;
module_param_string(ids, ids, sizeof(ids), 0);
MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the vfio driver, format is \"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\" and multiple comma separated entries can be specified");

static bool nointxmask;
module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(nointxmask,
		  "Disable support for PCI 2.3 style INTx masking.  If this resolves problems for specific devices, report lspci -vvvxxx to linux-pci@vger.kernel.org so the device can be fixed automatically via the broken_intx_masking flag.");

#ifdef CONFIG_VFIO_PCI_VGA
static bool disable_vga;
module_param(disable_vga, bool, S_IRUGO);
MODULE_PARM_DESC(disable_vga, "Disable VGA resource access through vfio-pci");
#endif

static bool disable_idle_d3;
module_param(disable_idle_d3, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(disable_idle_d3,
		 "Disable using the PCI D3 low power state for idle, unused devices");

static bool enable_sriov;
#ifdef CONFIG_PCI_IOV
module_param(enable_sriov, bool, 0644);
MODULE_PARM_DESC(enable_sriov, "Enable support for SR-IOV configuration.  Enabling SR-IOV on a PF typically requires support of the userspace PF driver, enabling VFs without such support may result in non-functional VFs or PF.");
#endif

static bool disable_denylist;
module_param(disable_denylist, bool, 0444);
MODULE_PARM_DESC(disable_denylist, "Disable use of device denylist. Disabling the denylist allows binding to devices with known errata that may lead to exploitable stability or security issues when accessed by untrusted users.");

static bool vfio_pci_dev_in_denylist(struct pci_dev *pdev)
{
	switch (pdev->vendor) {
	case PCI_VENDOR_ID_INTEL:
		switch (pdev->device) {
		case PCI_DEVICE_ID_INTEL_QAT_C3XXX:
		case PCI_DEVICE_ID_INTEL_QAT_C3XXX_VF:
		case PCI_DEVICE_ID_INTEL_QAT_C62X:
		case PCI_DEVICE_ID_INTEL_QAT_C62X_VF:
		case PCI_DEVICE_ID_INTEL_QAT_DH895XCC:
		case PCI_DEVICE_ID_INTEL_QAT_DH895XCC_VF:
			return true;
		default:
			return false;
		}
	}

	return false;
}

static bool vfio_pci_is_denylisted(struct pci_dev *pdev)
{
	if (!vfio_pci_dev_in_denylist(pdev))
		return false;

	if (disable_denylist) {
		pci_warn(pdev,
			 "device denylist disabled - allowing device %04x:%04x.\n",
			 pdev->vendor, pdev->device);
		return false;
	}

	pci_warn(pdev, "%04x:%04x exists in vfio-pci device denylist, driver probing disallowed.\n",
		 pdev->vendor, pdev->device);

	return true;
}

static int vfio_pci_open_device(struct vfio_device *core_vdev)
{
	struct vfio_pci_core_device *vdev =
		container_of(core_vdev, struct vfio_pci_core_device, vdev);
	struct pci_dev *pdev = vdev->pdev;
	int ret;

	ret = vfio_pci_core_enable(vdev);
	if (ret)
		return ret;

	if (vfio_pci_is_vga(pdev) &&
	    pdev->vendor == PCI_VENDOR_ID_INTEL &&
	    IS_ENABLED(CONFIG_VFIO_PCI_IGD)) {
		ret = vfio_pci_igd_init(vdev);
		if (ret && ret != -ENODEV) {
			pci_warn(pdev, "Failed to setup Intel IGD regions\n");
			vfio_pci_core_disable(vdev);
			return ret;
		}
	}

	vfio_pci_core_finish_enable(vdev);

	return 0;
}

static const struct vfio_device_ops vfio_pci_ops = {
	.name		= "vfio-pci",
	.init		= vfio_pci_core_init_dev,
	.release	= vfio_pci_core_release_dev,
	.open_device	= vfio_pci_open_device,
	.close_device	= vfio_pci_core_close_device,
	.ioctl		= vfio_pci_core_ioctl,
	.device_feature = vfio_pci_core_ioctl_feature,
	.read		= vfio_pci_core_read,
	.write		= vfio_pci_core_write,
	.mmap		= vfio_pci_core_mmap,
	.request	= vfio_pci_core_request,
	.match		= vfio_pci_core_match,
	.bind_iommufd	= vfio_iommufd_physical_bind,
	.unbind_iommufd	= vfio_iommufd_physical_unbind,
	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
};

static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
	struct vfio_pci_core_device *vdev;
	int ret;

	if (vfio_pci_is_denylisted(pdev))
		return -EINVAL;

	vdev = vfio_alloc_device(vfio_pci_core_device, vdev, &pdev->dev,
				 &vfio_pci_ops);
	if (IS_ERR(vdev))
		return PTR_ERR(vdev);

	dev_set_drvdata(&pdev->dev, vdev);
	ret = vfio_pci_core_register_device(vdev);
	if (ret)
		goto out_put_vdev;
	return 0;

out_put_vdev:
	vfio_put_device(&vdev->vdev);
	return ret;
}

static void vfio_pci_remove(struct pci_dev *pdev)
{
	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);

	vfio_pci_core_unregister_device(vdev);
	vfio_put_device(&vdev->vdev);
}

static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
{
	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);

	if (!enable_sriov)
		return -ENOENT;

	return vfio_pci_core_sriov_configure(vdev, nr_virtfn);
}

static const struct pci_device_id vfio_pci_table[] = {
	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_ANY_ID, PCI_ANY_ID) }, /* match all by default */
	{}
};

MODULE_DEVICE_TABLE(pci, vfio_pci_table);

static struct pci_driver vfio_pci_driver = {
	.name			= "vfio-pci",
	.id_table		= vfio_pci_table,
	.probe			= vfio_pci_probe,
	.remove			= vfio_pci_remove,
	.sriov_configure	= vfio_pci_sriov_configure,
	.err_handler		= &vfio_pci_core_err_handlers,
	.driver_managed_dma	= true,
};

static void __init vfio_pci_fill_ids(void)
{
	char *p, *id;
	int rc;

	/* no ids passed actually */
	if (ids[0] == '\0')
		return;

	/* add ids specified in the module parameter */
	p = ids;
	while ((id = strsep(&p, ","))) {
		unsigned int vendor, device, subvendor = PCI_ANY_ID,
			subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
		int fields;

		if (!strlen(id))
			continue;

		fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
				&vendor, &device, &subvendor, &subdevice,
				&class, &class_mask);

		if (fields < 2) {
			pr_warn("invalid id string \"%s\"\n", id);
			continue;
		}

		rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
				   subvendor, subdevice, class, class_mask, 0);
		if (rc)
			pr_warn("failed to add dynamic id [%04x:%04x[%04x:%04x]] class %#08x/%08x (%d)\n",
				vendor, device, subvendor, subdevice,
				class, class_mask, rc);
		else
			pr_info("add [%04x:%04x[%04x:%04x]] class %#08x/%08x\n",
				vendor, device, subvendor, subdevice,
				class, class_mask);
	}
}

static int __init vfio_pci_init(void)
{
	int ret;
	bool is_disable_vga = true;

#ifdef CONFIG_VFIO_PCI_VGA
	is_disable_vga = disable_vga;
#endif

	vfio_pci_core_set_params(nointxmask, is_disable_vga, disable_idle_d3);

	/* Register and scan for devices */
	ret = pci_register_driver(&vfio_pci_driver);
	if (ret)
		return ret;

	vfio_pci_fill_ids();

	if (disable_denylist)
		pr_warn("device denylist disabled.\n");

	return 0;
}
module_init(vfio_pci_init);

static void __exit vfio_pci_cleanup(void)
{
	pci_unregister_driver(&vfio_pci_driver);
}
module_exit(vfio_pci_cleanup);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);