1What: /sys/bus/pci/drivers/.../bind 2What: /sys/devices/pciX/.../bind 3Date: December 2003 4Contact: linux-pci@vger.kernel.org 5Description: 6 Writing a device location to this file will cause 7 the driver to attempt to bind to the device found at 8 this location. This is useful for overriding default 9 bindings. The format for the location is: DDDD:BB:DD.F. 10 That is Domain:Bus:Device.Function and is the same as 11 found in /sys/bus/pci/devices/. For example:: 12 13 # echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/bind 14 15 (Note: kernels before 2.6.28 may require echo -n). 16 17What: /sys/bus/pci/drivers/.../unbind 18What: /sys/devices/pciX/.../unbind 19Date: December 2003 20Contact: linux-pci@vger.kernel.org 21Description: 22 Writing a device location to this file will cause the 23 driver to attempt to unbind from the device found at 24 this location. This may be useful when overriding default 25 bindings. The format for the location is: DDDD:BB:DD.F. 26 That is Domain:Bus:Device.Function and is the same as 27 found in /sys/bus/pci/devices/. For example:: 28 29 # echo 0000:00:19.0 > /sys/bus/pci/drivers/foo/unbind 30 31 (Note: kernels before 2.6.28 may require echo -n). 32 33What: /sys/bus/pci/drivers/.../new_id 34What: /sys/devices/pciX/.../new_id 35Date: December 2003 36Contact: linux-pci@vger.kernel.org 37Description: 38 Writing a device ID to this file will attempt to 39 dynamically add a new device ID to a PCI device driver. 40 This may allow the driver to support more hardware than 41 was included in the driver's static device ID support 42 table at compile time. The format for the device ID is: 43 VVVV DDDD SVVV SDDD CCCC MMMM PPPP. That is Vendor ID, 44 Device ID, Subsystem Vendor ID, Subsystem Device ID, 45 Class, Class Mask, and Private Driver Data. The Vendor ID 46 and Device ID fields are required, the rest are optional. 47 Upon successfully adding an ID, the driver will probe 48 for the device and attempt to bind to it. For example:: 49 50 # echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_id 51 52What: /sys/bus/pci/drivers/.../remove_id 53What: /sys/devices/pciX/.../remove_id 54Date: February 2009 55Contact: Chris Wright <chrisw@sous-sol.org> 56Description: 57 Writing a device ID to this file will remove an ID 58 that was dynamically added via the new_id sysfs entry. 59 The format for the device ID is: 60 VVVV DDDD SVVV SDDD CCCC MMMM. That is Vendor ID, Device 61 ID, Subsystem Vendor ID, Subsystem Device ID, Class, 62 and Class Mask. The Vendor ID and Device ID fields are 63 required, the rest are optional. After successfully 64 removing an ID, the driver will no longer support the 65 device. This is useful to ensure auto probing won't 66 match the driver to the device. For example:: 67 68 # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id 69 70What: /sys/bus/pci/rescan 71Date: January 2009 72Contact: Linux PCI developers <linux-pci@vger.kernel.org> 73Description: 74 Writing a non-zero value to this attribute will 75 force a rescan of all PCI buses in the system, and 76 re-discover previously removed devices. 77 78What: /sys/bus/pci/devices/.../msi_bus 79Date: September 2014 80Contact: Linux PCI developers <linux-pci@vger.kernel.org> 81Description: 82 Writing a zero value to this attribute disallows MSI and 83 MSI-X for any future drivers of the device. If the device 84 is a bridge, MSI and MSI-X will be disallowed for future 85 drivers of all child devices under the bridge. Drivers 86 must be reloaded for the new setting to take effect. 87 88What: /sys/bus/pci/devices/.../msi_irqs/ 89Date: September, 2011 90Contact: Neil Horman <nhorman@tuxdriver.com> 91Description: 92 The /sys/devices/.../msi_irqs directory contains a variable set 93 of files, with each file being named after a corresponding msi 94 irq vector allocated to that device. 95 96What: /sys/bus/pci/devices/.../msi_irqs/<N> 97Date: September 2011 98Contact: Neil Horman <nhorman@tuxdriver.com> 99Description: 100 This attribute indicates the mode that the irq vector named by 101 the file is in (msi vs. msix) 102 103What: /sys/bus/pci/devices/.../remove 104Date: January 2009 105Contact: Linux PCI developers <linux-pci@vger.kernel.org> 106Description: 107 Writing a non-zero value to this attribute will 108 hot-remove the PCI device and any of its children. 109 110What: /sys/bus/pci/devices/.../pci_bus/.../rescan 111Date: May 2011 112Contact: Linux PCI developers <linux-pci@vger.kernel.org> 113Description: 114 Writing a non-zero value to this attribute will 115 force a rescan of the bus and all child buses, 116 and re-discover devices removed earlier from this 117 part of the device tree. 118 119What: /sys/bus/pci/devices/.../rescan 120Date: January 2009 121Contact: Linux PCI developers <linux-pci@vger.kernel.org> 122Description: 123 Writing a non-zero value to this attribute will 124 force a rescan of the device's parent bus and all 125 child buses, and re-discover devices removed earlier 126 from this part of the device tree. 127 128What: /sys/bus/pci/devices/.../reset_method 129Date: August 2021 130Contact: Amey Narkhede <ameynarkhede03@gmail.com> 131Description: 132 Some devices allow an individual function to be reset 133 without affecting other functions in the same slot. 134 135 For devices that have this support, a file named 136 reset_method is present in sysfs. Reading this file 137 gives names of the supported and enabled reset methods and 138 their ordering. Writing a space-separated list of names of 139 reset methods sets the reset methods and ordering to be 140 used when resetting the device. Writing an empty string 141 disables the ability to reset the device. Writing 142 "default" enables all supported reset methods in the 143 default ordering. 144 145What: /sys/bus/pci/devices/.../reset 146Date: July 2009 147Contact: Michael S. Tsirkin <mst@redhat.com> 148Description: 149 Some devices allow an individual function to be reset 150 without affecting other functions in the same device. 151 For devices that have this support, a file named reset 152 will be present in sysfs. Writing 1 to this file 153 will perform reset. 154 155What: /sys/bus/pci/devices/.../vpd 156Date: February 2008 157Contact: Ben Hutchings <bwh@kernel.org> 158Description: 159 A file named vpd in a device directory will be a 160 binary file containing the Vital Product Data for the 161 device. It should follow the VPD format defined in 162 PCI Specification 2.1 or 2.2, but users should consider 163 that some devices may have incorrectly formatted data. 164 If the underlying VPD has a writable section then the 165 corresponding section of this file will be writable. 166 167What: /sys/bus/pci/devices/.../virtfn<N> 168Date: March 2009 169Contact: Yu Zhao <yu.zhao@intel.com> 170Description: 171 This symbolic link appears when hardware supports the SR-IOV 172 capability and the Physical Function driver has enabled it. 173 The symbolic link points to the PCI device sysfs entry of the 174 Virtual Function whose index is N (0...MaxVFs-1). 175 176What: /sys/bus/pci/devices/.../dep_link 177Date: March 2009 178Contact: Yu Zhao <yu.zhao@intel.com> 179Description: 180 This symbolic link appears when hardware supports the SR-IOV 181 capability and the Physical Function driver has enabled it, 182 and this device has vendor specific dependencies with others. 183 The symbolic link points to the PCI device sysfs entry of 184 Physical Function this device depends on. 185 186What: /sys/bus/pci/devices/.../physfn 187Date: March 2009 188Contact: Yu Zhao <yu.zhao@intel.com> 189Description: 190 This symbolic link appears when a device is a Virtual Function. 191 The symbolic link points to the PCI device sysfs entry of the 192 Physical Function this device associates with. 193 194What: /sys/bus/pci/devices/.../modalias 195Date: May 2005 196Contact: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 197Description: 198 This attribute indicates the PCI ID of the device object. 199 200 That is in the format: 201 pci:vXXXXXXXXdXXXXXXXXsvXXXXXXXXsdXXXXXXXXbcXXscXXiXX, 202 where: 203 204 - vXXXXXXXX contains the vendor ID; 205 - dXXXXXXXX contains the device ID; 206 - svXXXXXXXX contains the sub-vendor ID; 207 - sdXXXXXXXX contains the subsystem device ID; 208 - bcXX contains the device class; 209 - scXX contains the device subclass; 210 - iXX contains the device class programming interface. 211 212What: /sys/bus/pci/slots/.../module 213Date: June 2009 214Contact: linux-pci@vger.kernel.org 215Description: 216 This symbolic link points to the PCI hotplug controller driver 217 module that manages the hotplug slot. 218 219What: /sys/bus/pci/devices/.../label 220Date: July 2010 221Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com 222Description: 223 Reading this attribute will provide the firmware 224 given name (SMBIOS type 41 string or ACPI _DSM string) of 225 the PCI device. The attribute will be created only 226 if the firmware has given a name to the PCI device. 227 ACPI _DSM string name will be given priority if the 228 system firmware provides SMBIOS type 41 string also. 229Users: 230 Userspace applications interested in knowing the 231 firmware assigned name of the PCI device. 232 233What: /sys/bus/pci/devices/.../index 234Date: July 2010 235Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com 236Description: 237 Reading this attribute will provide the firmware given instance 238 number of the PCI device. Depending on the platform this can 239 be for example the SMBIOS type 41 device type instance or the 240 user-defined ID (UID) on s390. The attribute will be created 241 only if the firmware has given an instance number to the PCI 242 device and that number is guaranteed to uniquely identify the 243 device in the system. 244Users: 245 Userspace applications interested in knowing the 246 firmware assigned device type instance of the PCI 247 device that can help in understanding the firmware 248 intended order of the PCI device. 249 250What: /sys/bus/pci/devices/.../acpi_index 251Date: July 2010 252Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com 253Description: 254 Reading this attribute will provide the firmware 255 given instance (ACPI _DSM instance number) of the PCI device. 256 The attribute will be created only if the firmware has given 257 an instance number to the PCI device. ACPI _DSM instance number 258 will be given priority if the system firmware provides SMBIOS 259 type 41 device type instance also. 260Users: 261 Userspace applications interested in knowing the 262 firmware assigned instance number of the PCI 263 device that can help in understanding the firmware 264 intended order of the PCI device. 265 266What: /sys/bus/pci/devices/.../d3cold_allowed 267Date: July 2012 268Contact: Huang Ying <ying.huang@intel.com> 269Description: 270 d3cold_allowed is bit to control whether the corresponding PCI 271 device can be put into D3Cold state. If it is cleared, the 272 device will never be put into D3Cold state. If it is set, the 273 device may be put into D3Cold state if other requirements are 274 satisfied too. Reading this attribute will show the current 275 value of d3cold_allowed bit. Writing this attribute will set 276 the value of d3cold_allowed bit. 277 278What: /sys/bus/pci/devices/.../sriov_totalvfs 279Date: November 2012 280Contact: Donald Dutile <ddutile@redhat.com> 281Description: 282 This file appears when a physical PCIe device supports SR-IOV. 283 Userspace applications can read this file to determine the 284 maximum number of Virtual Functions (VFs) a PCIe physical 285 function (PF) can support. Typically, this is the value reported 286 in the PF's SR-IOV extended capability structure's TotalVFs 287 element. Drivers have the ability at probe time to reduce the 288 value read from this file via the pci_sriov_set_totalvfs() 289 function. 290 291What: /sys/bus/pci/devices/.../sriov_numvfs 292Date: November 2012 293Contact: Donald Dutile <ddutile@redhat.com> 294Description: 295 This file appears when a physical PCIe device supports SR-IOV. 296 Userspace applications can read and write to this file to 297 determine and control the enablement or disablement of Virtual 298 Functions (VFs) on the physical function (PF). A read of this 299 file will return the number of VFs that are enabled on this PF. 300 A number written to this file will enable the specified 301 number of VFs. A userspace application would typically read the 302 file and check that the value is zero, and then write the number 303 of VFs that should be enabled on the PF; the value written 304 should be less than or equal to the value in the sriov_totalvfs 305 file. A userspace application wanting to disable the VFs would 306 write a zero to this file. The core ensures that valid values 307 are written to this file, and returns errors when values are not 308 valid. For example, writing a 2 to this file when sriov_numvfs 309 is not 0 and not 2 already will return an error. Writing a 10 310 when the value of sriov_totalvfs is 8 will return an error. 311 312What: /sys/bus/pci/devices/.../driver_override 313Date: April 2014 314Contact: Alex Williamson <alex.williamson@redhat.com> 315Description: 316 This file allows the driver for a device to be specified which 317 will override standard static and dynamic ID matching. When 318 specified, only a driver with a name matching the value written 319 to driver_override will have an opportunity to bind to the 320 device. The override is specified by writing a string to the 321 driver_override file (echo pci-stub > driver_override) and 322 may be cleared with an empty string (echo > driver_override). 323 This returns the device to standard matching rules binding. 324 Writing to driver_override does not automatically unbind the 325 device from its current driver or make any attempt to 326 automatically load the specified driver. If no driver with a 327 matching name is currently loaded in the kernel, the device 328 will not bind to any driver. This also allows devices to 329 opt-out of driver binding using a driver_override name such as 330 "none". Only a single driver may be specified in the override, 331 there is no support for parsing delimiters. 332 333What: /sys/bus/pci/devices/.../numa_node 334Date: Oct 2014 335Contact: Prarit Bhargava <prarit@redhat.com> 336Description: 337 This file contains the NUMA node to which the PCI device is 338 attached, or -1 if the node is unknown. The initial value 339 comes from an ACPI _PXM method or a similar firmware 340 source. If that is missing or incorrect, this file can be 341 written to override the node. In that case, please report 342 a firmware bug to the system vendor. Writing to this file 343 taints the kernel with TAINT_FIRMWARE_WORKAROUND, which 344 reduces the supportability of your system. 345 346What: /sys/bus/pci/devices/.../revision 347Date: November 2016 348Contact: Emil Velikov <emil.l.velikov@gmail.com> 349Description: 350 This file contains the revision field of the PCI device. 351 The value comes from device config space. The file is read only. 352 353What: /sys/bus/pci/devices/.../sriov_drivers_autoprobe 354Date: April 2017 355Contact: Bodong Wang<bodong@mellanox.com> 356Description: 357 This file is associated with the PF of a device that 358 supports SR-IOV. It determines whether newly-enabled VFs 359 are immediately bound to a driver. It initially contains 360 1, which means the kernel automatically binds VFs to a 361 compatible driver immediately after they are enabled. If 362 an application writes 0 to the file before enabling VFs, 363 the kernel will not bind VFs to a driver. 364 365 A typical use case is to write 0 to this file, then enable 366 VFs, then assign the newly-created VFs to virtual machines. 367 Note that changing this file does not affect already- 368 enabled VFs. In this scenario, the user must first disable 369 the VFs, write 0 to sriov_drivers_autoprobe, then re-enable 370 the VFs. 371 372 This is similar to /sys/bus/pci/drivers_autoprobe, but 373 affects only the VFs associated with a specific PF. 374 375What: /sys/bus/pci/devices/.../p2pmem/size 376Date: November 2017 377Contact: Logan Gunthorpe <logang@deltatee.com> 378Description: 379 If the device has any Peer-to-Peer memory registered, this 380 file contains the total amount of memory that the device 381 provides (in decimal). 382 383What: /sys/bus/pci/devices/.../p2pmem/available 384Date: November 2017 385Contact: Logan Gunthorpe <logang@deltatee.com> 386Description: 387 If the device has any Peer-to-Peer memory registered, this 388 file contains the amount of memory that has not been 389 allocated (in decimal). 390 391What: /sys/bus/pci/devices/.../p2pmem/published 392Date: November 2017 393Contact: Logan Gunthorpe <logang@deltatee.com> 394Description: 395 If the device has any Peer-to-Peer memory registered, this 396 file contains a '1' if the memory has been published for 397 use outside the driver that owns the device. 398 399What: /sys/bus/pci/devices/.../link/clkpm 400 /sys/bus/pci/devices/.../link/l0s_aspm 401 /sys/bus/pci/devices/.../link/l1_aspm 402 /sys/bus/pci/devices/.../link/l1_1_aspm 403 /sys/bus/pci/devices/.../link/l1_2_aspm 404 /sys/bus/pci/devices/.../link/l1_1_pcipm 405 /sys/bus/pci/devices/.../link/l1_2_pcipm 406Date: October 2019 407Contact: Heiner Kallweit <hkallweit1@gmail.com> 408Description: If ASPM is supported for an endpoint, these files can be 409 used to disable or enable the individual power management 410 states. Write y/1/on to enable, n/0/off to disable. 411 412What: /sys/bus/pci/devices/.../power_state 413Date: November 2020 414Contact: Linux PCI developers <linux-pci@vger.kernel.org> 415Description: 416 This file contains the current PCI power state of the device. 417 The value comes from the PCI kernel device state and can be one 418 of: "unknown", "error", "D0", D1", "D2", "D3hot", "D3cold". 419 The file is read only. 420 421What: /sys/bus/pci/devices/.../sriov_vf_total_msix 422Date: January 2021 423Contact: Leon Romanovsky <leonro@nvidia.com> 424Description: 425 This file is associated with a SR-IOV physical function (PF). 426 It contains the total number of MSI-X vectors available for 427 assignment to all virtual functions (VFs) associated with PF. 428 The value will be zero if the device doesn't support this 429 functionality. For supported devices, the value will be 430 constant and won't be changed after MSI-X vectors assignment. 431 432What: /sys/bus/pci/devices/.../sriov_vf_msix_count 433Date: January 2021 434Contact: Leon Romanovsky <leonro@nvidia.com> 435Description: 436 This file is associated with a SR-IOV virtual function (VF). 437 It allows configuration of the number of MSI-X vectors for 438 the VF. This allows devices that have a global pool of MSI-X 439 vectors to optimally divide them between VFs based on VF usage. 440 441 The values accepted are: 442 * > 0 - this number will be reported as the Table Size in the 443 VF's MSI-X capability 444 * < 0 - not valid 445 * = 0 - will reset to the device default value 446 447 The file is writable if the PF is bound to a driver that 448 implements ->sriov_set_msix_vec_count(). 449