xref: /openbmc/linux/drivers/vfio/pci/vfio_pci.c (revision 6562c9ac)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved
4  *
5  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
6  *     Author: Alex Williamson <alex.williamson@redhat.com>
7  *
8  * Derived from original vfio:
9  * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
10  * Author: Tom Lyon, pugs@cisco.com
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/device.h>
16 #include <linux/eventfd.h>
17 #include <linux/file.h>
18 #include <linux/interrupt.h>
19 #include <linux/iommu.h>
20 #include <linux/module.h>
21 #include <linux/mutex.h>
22 #include <linux/notifier.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/slab.h>
25 #include <linux/types.h>
26 #include <linux/uaccess.h>
27 
28 #include <linux/vfio_pci_core.h>
29 
30 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
31 #define DRIVER_DESC     "VFIO PCI - User Level meta-driver"
32 
33 static char ids[1024] __initdata;
34 module_param_string(ids, ids, sizeof(ids), 0);
35 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");
36 
37 static bool nointxmask;
38 module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR);
39 MODULE_PARM_DESC(nointxmask,
40 		  "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.");
41 
42 #ifdef CONFIG_VFIO_PCI_VGA
43 static bool disable_vga;
44 module_param(disable_vga, bool, S_IRUGO);
45 MODULE_PARM_DESC(disable_vga, "Disable VGA resource access through vfio-pci");
46 #endif
47 
48 static bool disable_idle_d3;
49 module_param(disable_idle_d3, bool, S_IRUGO | S_IWUSR);
50 MODULE_PARM_DESC(disable_idle_d3,
51 		 "Disable using the PCI D3 low power state for idle, unused devices");
52 
53 static bool enable_sriov;
54 #ifdef CONFIG_PCI_IOV
55 module_param(enable_sriov, bool, 0644);
56 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.");
57 #endif
58 
59 static bool disable_denylist;
60 module_param(disable_denylist, bool, 0444);
61 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.");
62 
63 static bool vfio_pci_dev_in_denylist(struct pci_dev *pdev)
64 {
65 	switch (pdev->vendor) {
66 	case PCI_VENDOR_ID_INTEL:
67 		switch (pdev->device) {
68 		case PCI_DEVICE_ID_INTEL_QAT_C3XXX:
69 		case PCI_DEVICE_ID_INTEL_QAT_C3XXX_VF:
70 		case PCI_DEVICE_ID_INTEL_QAT_C62X:
71 		case PCI_DEVICE_ID_INTEL_QAT_C62X_VF:
72 		case PCI_DEVICE_ID_INTEL_QAT_DH895XCC:
73 		case PCI_DEVICE_ID_INTEL_QAT_DH895XCC_VF:
74 			return true;
75 		default:
76 			return false;
77 		}
78 	}
79 
80 	return false;
81 }
82 
83 static bool vfio_pci_is_denylisted(struct pci_dev *pdev)
84 {
85 	if (!vfio_pci_dev_in_denylist(pdev))
86 		return false;
87 
88 	if (disable_denylist) {
89 		pci_warn(pdev,
90 			 "device denylist disabled - allowing device %04x:%04x.\n",
91 			 pdev->vendor, pdev->device);
92 		return false;
93 	}
94 
95 	pci_warn(pdev, "%04x:%04x exists in vfio-pci device denylist, driver probing disallowed.\n",
96 		 pdev->vendor, pdev->device);
97 
98 	return true;
99 }
100 
101 static int vfio_pci_open_device(struct vfio_device *core_vdev)
102 {
103 	struct vfio_pci_core_device *vdev =
104 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
105 	struct pci_dev *pdev = vdev->pdev;
106 	int ret;
107 
108 	ret = vfio_pci_core_enable(vdev);
109 	if (ret)
110 		return ret;
111 
112 	if (vfio_pci_is_vga(pdev) &&
113 	    pdev->vendor == PCI_VENDOR_ID_INTEL &&
114 	    IS_ENABLED(CONFIG_VFIO_PCI_IGD)) {
115 		ret = vfio_pci_igd_init(vdev);
116 		if (ret && ret != -ENODEV) {
117 			pci_warn(pdev, "Failed to setup Intel IGD regions\n");
118 			vfio_pci_core_disable(vdev);
119 			return ret;
120 		}
121 	}
122 
123 	vfio_pci_core_finish_enable(vdev);
124 
125 	return 0;
126 }
127 
128 static const struct vfio_device_ops vfio_pci_ops = {
129 	.name		= "vfio-pci",
130 	.open_device	= vfio_pci_open_device,
131 	.close_device	= vfio_pci_core_close_device,
132 	.ioctl		= vfio_pci_core_ioctl,
133 	.device_feature = vfio_pci_core_ioctl_feature,
134 	.read		= vfio_pci_core_read,
135 	.write		= vfio_pci_core_write,
136 	.mmap		= vfio_pci_core_mmap,
137 	.request	= vfio_pci_core_request,
138 	.match		= vfio_pci_core_match,
139 };
140 
141 static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
142 {
143 	struct vfio_pci_core_device *vdev;
144 	int ret;
145 
146 	if (vfio_pci_is_denylisted(pdev))
147 		return -EINVAL;
148 
149 	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
150 	if (!vdev)
151 		return -ENOMEM;
152 	vfio_pci_core_init_device(vdev, pdev, &vfio_pci_ops);
153 
154 	dev_set_drvdata(&pdev->dev, vdev);
155 	ret = vfio_pci_core_register_device(vdev);
156 	if (ret)
157 		goto out_free;
158 	return 0;
159 
160 out_free:
161 	vfio_pci_core_uninit_device(vdev);
162 	kfree(vdev);
163 	return ret;
164 }
165 
166 static void vfio_pci_remove(struct pci_dev *pdev)
167 {
168 	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);
169 
170 	vfio_pci_core_unregister_device(vdev);
171 	vfio_pci_core_uninit_device(vdev);
172 	kfree(vdev);
173 }
174 
175 static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
176 {
177 	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);
178 
179 	if (!enable_sriov)
180 		return -ENOENT;
181 
182 	return vfio_pci_core_sriov_configure(vdev, nr_virtfn);
183 }
184 
185 static const struct pci_device_id vfio_pci_table[] = {
186 	{ PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_ANY_ID, PCI_ANY_ID) }, /* match all by default */
187 	{}
188 };
189 
190 MODULE_DEVICE_TABLE(pci, vfio_pci_table);
191 
192 static struct pci_driver vfio_pci_driver = {
193 	.name			= "vfio-pci",
194 	.id_table		= vfio_pci_table,
195 	.probe			= vfio_pci_probe,
196 	.remove			= vfio_pci_remove,
197 	.sriov_configure	= vfio_pci_sriov_configure,
198 	.err_handler		= &vfio_pci_core_err_handlers,
199 	.driver_managed_dma	= true,
200 };
201 
202 static void __init vfio_pci_fill_ids(void)
203 {
204 	char *p, *id;
205 	int rc;
206 
207 	/* no ids passed actually */
208 	if (ids[0] == '\0')
209 		return;
210 
211 	/* add ids specified in the module parameter */
212 	p = ids;
213 	while ((id = strsep(&p, ","))) {
214 		unsigned int vendor, device, subvendor = PCI_ANY_ID,
215 			subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
216 		int fields;
217 
218 		if (!strlen(id))
219 			continue;
220 
221 		fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
222 				&vendor, &device, &subvendor, &subdevice,
223 				&class, &class_mask);
224 
225 		if (fields < 2) {
226 			pr_warn("invalid id string \"%s\"\n", id);
227 			continue;
228 		}
229 
230 		rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
231 				   subvendor, subdevice, class, class_mask, 0);
232 		if (rc)
233 			pr_warn("failed to add dynamic id [%04x:%04x[%04x:%04x]] class %#08x/%08x (%d)\n",
234 				vendor, device, subvendor, subdevice,
235 				class, class_mask, rc);
236 		else
237 			pr_info("add [%04x:%04x[%04x:%04x]] class %#08x/%08x\n",
238 				vendor, device, subvendor, subdevice,
239 				class, class_mask);
240 	}
241 }
242 
243 static int __init vfio_pci_init(void)
244 {
245 	int ret;
246 	bool is_disable_vga = true;
247 
248 #ifdef CONFIG_VFIO_PCI_VGA
249 	is_disable_vga = disable_vga;
250 #endif
251 
252 	vfio_pci_core_set_params(nointxmask, is_disable_vga, disable_idle_d3);
253 
254 	/* Register and scan for devices */
255 	ret = pci_register_driver(&vfio_pci_driver);
256 	if (ret)
257 		return ret;
258 
259 	vfio_pci_fill_ids();
260 
261 	if (disable_denylist)
262 		pr_warn("device denylist disabled.\n");
263 
264 	return 0;
265 }
266 module_init(vfio_pci_init);
267 
268 static void __exit vfio_pci_cleanup(void)
269 {
270 	pci_unregister_driver(&vfio_pci_driver);
271 }
272 module_exit(vfio_pci_cleanup);
273 
274 MODULE_LICENSE("GPL v2");
275 MODULE_AUTHOR(DRIVER_AUTHOR);
276 MODULE_DESCRIPTION(DRIVER_DESC);
277