tree: https://github.com/jgunthorpe/linux for-yishai head: 578832b9b1266b9c2fa0205513bd7570867bf3e5 commit: 755823a03dd267576194ffe22f6640eca356dfdf [9/18] vfio: Define device migration protocol v2 config: powerpc-allmodconfig (https://download.01.org/0day-ci/archive/20220122/202201221146.IDixXFOw-lk...) compiler: powerpc-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/jgunthorpe/linux/commit/755823a03dd267576194ffe22f6640... git remote add jgunthorpe https://github.com/jgunthorpe/linux git fetch --no-tags jgunthorpe for-yishai git checkout 755823a03dd267576194ffe22f6640eca356dfdf # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash drivers/vfio/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; Note: the jgunthorpe/for-yishai HEAD 578832b9b1266b9c2fa0205513bd7570867bf3e5 builds fine. It only hurts bisectability. All errors (new ones prefixed by >>): In file included from include/linux/vfio.h:16, from drivers/vfio/vfio.c:32: 608 | #define VFIO_DEVICE_STATE_STOP (0) | ^ include/uapi/linux/vfio.h:1098:9: note: in expansion of macro 'VFIO_DEVICE_STATE_STOP' 1098 | VFIO_DEVICE_STATE_STOP = 1, | ^~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c: In function 'vfio_mig_get_next_state': 1600 | [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ | VFIO_DEVICE_STATE_STOP drivers/vfio/vfio.c:1600:26: note: each undeclared identifier is reported only once for each function it appears in drivers/vfio/vfio.c:1600:26: note: (near initialization for 'vfio_from_fsm_table[0]') drivers/vfio/vfio.c:1602:53: warning: initialized field overwritten [-Woverride-init] 1602 | [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, | ^~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1602:53: note: (near initialization for 'vfio_from_fsm_table[0][0]') drivers/vfio/vfio.c:1607:26: error: array index in initializer not of integer type 1607 | [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1607:26: note: (near initialization for 'vfio_from_fsm_table[1]') drivers/vfio/vfio.c:1609:53: warning: initialized field overwritten [-Woverride-init] 1609 | [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, | ^~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1609:53: note: (near initialization for 'vfio_from_fsm_table[1][0]') drivers/vfio/vfio.c:1611:18: error: array index in initializer not of integer type 1611 | [VFIO_DEVICE_STATE_STOP_COPY] = { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1611:18: note: (near initialization for 'vfio_from_fsm_table') drivers/vfio/vfio.c:1614:26: error: array index in initializer not of integer type 1614 | [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1614:26: note: (near initialization for 'vfio_from_fsm_table[2]') drivers/vfio/vfio.c:1616:53: warning: initialized field overwritten [-Woverride-init] 1616 | [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, | ^~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1616:53: note: (near initialization for 'vfio_from_fsm_table[2][0]') drivers/vfio/vfio.c:1621:26: error: array index in initializer not of integer type 1621 | [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1621:26: note: (near initialization for 'vfio_from_fsm_table[4]') drivers/vfio/vfio.c:1623:53: warning: initialized field overwritten [-Woverride-init] 1623 | [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, | ^~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1623:53: note: (near initialization for 'vfio_from_fsm_table[4][0]') drivers/vfio/vfio.c:1628:26: error: array index in initializer not of integer type 1628 | [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_ERROR, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1628:26: note: (near initialization for 'vfio_from_fsm_table[0]') drivers/vfio/vfio.c:1630:53: warning: initialized field overwritten [-Woverride-init] 1630 | [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR, | ^~~~~~~~~~~~~~~~~~~~~~~ drivers/vfio/vfio.c:1630:53: note: (near initialization for 'vfio_from_fsm_table[0][0]') -- In file included from include/linux/vfio.h:16, from drivers/vfio/virqfd.c:10: 608 | #define VFIO_DEVICE_STATE_STOP (0) | ^ include/uapi/linux/vfio.h:1098:9: note: in expansion of macro 'VFIO_DEVICE_STATE_STOP' 1098 | VFIO_DEVICE_STATE_STOP = 1, | ^~~~~~~~~~~~~~~~~~~~~~ vim +608 include/uapi/linux/vfio.h a8a24f3f6e3810 Kirti Wankhede 2020-05-29 409 a8a24f3f6e3810 Kirti Wankhede 2020-05-29 410 /* a8a24f3f6e3810 Kirti Wankhede 2020-05-29 411 * The structure vfio_device_migration_info is placed at the 0th offset of a8a24f3f6e3810 Kirti Wankhede 2020-05-29 412 * the VFIO_REGION_SUBTYPE_MIGRATION region to get and set VFIO device related a8a24f3f6e3810 Kirti Wankhede 2020-05-29 413 * migration information. Field accesses from this structure are only supported a8a24f3f6e3810 Kirti Wankhede 2020-05-29 414 * at their native width and alignment. Otherwise, the result is undefined and a8a24f3f6e3810 Kirti Wankhede 2020-05-29 415 * vendor drivers should return an error. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 416 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 417 * device_state: (read/write) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 418 * - The user application writes to this field to inform the vendor driver a8a24f3f6e3810 Kirti Wankhede 2020-05-29 419 * about the device state to be transitioned to. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 420 * - The vendor driver should take the necessary actions to change the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 421 * device state. After successful transition to a given state, the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 422 * vendor driver should return success on write(device_state, state) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 423 * system call. If the device state transition fails, the vendor driver a8a24f3f6e3810 Kirti Wankhede 2020-05-29 424 * should return an appropriate -errno for the fault condition. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 425 * - On the user application side, if the device state transition fails, a8a24f3f6e3810 Kirti Wankhede 2020-05-29 426 * that is, if write(device_state, state) returns an error, read a8a24f3f6e3810 Kirti Wankhede 2020-05-29 427 * device_state again to determine the current state of the device from a8a24f3f6e3810 Kirti Wankhede 2020-05-29 428 * the vendor driver. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 429 * - The vendor driver should return previous state of the device unless a8a24f3f6e3810 Kirti Wankhede 2020-05-29 430 * the vendor driver has encountered an internal error, in which case a8a24f3f6e3810 Kirti Wankhede 2020-05-29 431 * the vendor driver may report the device_state VFIO_DEVICE_STATE_ERROR. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 432 * - The user application must use the device reset ioctl to recover the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 433 * device from VFIO_DEVICE_STATE_ERROR state. If the device is a8a24f3f6e3810 Kirti Wankhede 2020-05-29 434 * indicated to be in a valid device state by reading device_state, the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 435 * user application may attempt to transition the device to any valid a8a24f3f6e3810 Kirti Wankhede 2020-05-29 436 * state reachable from the current state or terminate itself. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 437 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 438 * device_state consists of 3 bits: a8a24f3f6e3810 Kirti Wankhede 2020-05-29 439 * - If bit 0 is set, it indicates the _RUNNING state. If bit 0 is clear, a8a24f3f6e3810 Kirti Wankhede 2020-05-29 440 * it indicates the _STOP state. When the device state is changed to a8a24f3f6e3810 Kirti Wankhede 2020-05-29 441 * _STOP, driver should stop the device before write() returns. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 442 * - If bit 1 is set, it indicates the _SAVING state, which means that the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 443 * driver should start gathering device state information that will be a8a24f3f6e3810 Kirti Wankhede 2020-05-29 444 * provided to the VFIO user application to save the device's state. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 445 * - If bit 2 is set, it indicates the _RESUMING state, which means that a8a24f3f6e3810 Kirti Wankhede 2020-05-29 446 * the driver should prepare to resume the device. Data provided through a8a24f3f6e3810 Kirti Wankhede 2020-05-29 447 * the migration region should be used to resume the device. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 448 * Bits 3 - 31 are reserved for future use. To preserve them, the user a8a24f3f6e3810 Kirti Wankhede 2020-05-29 449 * application should perform a read-modify-write operation on this a8a24f3f6e3810 Kirti Wankhede 2020-05-29 450 * field when modifying the specified bits. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 451 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 452 * +------- _RESUMING a8a24f3f6e3810 Kirti Wankhede 2020-05-29 453 * |+------ _SAVING a8a24f3f6e3810 Kirti Wankhede 2020-05-29 454 * ||+----- _RUNNING a8a24f3f6e3810 Kirti Wankhede 2020-05-29 455 * ||| a8a24f3f6e3810 Kirti Wankhede 2020-05-29 456 * 000b => Device Stopped, not saving or resuming a8a24f3f6e3810 Kirti Wankhede 2020-05-29 457 * 001b => Device running, which is the default state a8a24f3f6e3810 Kirti Wankhede 2020-05-29 458 * 010b => Stop the device & save the device state, stop-and-copy state a8a24f3f6e3810 Kirti Wankhede 2020-05-29 459 * 011b => Device running and save the device state, pre-copy state a8a24f3f6e3810 Kirti Wankhede 2020-05-29 460 * 100b => Device stopped and the device state is resuming a8a24f3f6e3810 Kirti Wankhede 2020-05-29 461 * 101b => Invalid state a8a24f3f6e3810 Kirti Wankhede 2020-05-29 462 * 110b => Error state a8a24f3f6e3810 Kirti Wankhede 2020-05-29 463 * 111b => Invalid state a8a24f3f6e3810 Kirti Wankhede 2020-05-29 464 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 465 * State transitions: a8a24f3f6e3810 Kirti Wankhede 2020-05-29 466 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 467 * _RESUMING _RUNNING Pre-copy Stop-and-copy _STOP a8a24f3f6e3810 Kirti Wankhede 2020-05-29 468 * (100b) (001b) (011b) (010b) (000b) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 469 * 0. Running or default state a8a24f3f6e3810 Kirti Wankhede 2020-05-29 470 * | a8a24f3f6e3810 Kirti Wankhede 2020-05-29 471 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 472 * 1. Normal Shutdown (optional) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 473 * |------------------------------------->| a8a24f3f6e3810 Kirti Wankhede 2020-05-29 474 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 475 * 2. Save the state or suspend a8a24f3f6e3810 Kirti Wankhede 2020-05-29 476 * |------------------------->|---------->| a8a24f3f6e3810 Kirti Wankhede 2020-05-29 477 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 478 * 3. Save the state during live migration a8a24f3f6e3810 Kirti Wankhede 2020-05-29 479 * |----------->|------------>|---------->| a8a24f3f6e3810 Kirti Wankhede 2020-05-29 480 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 481 * 4. Resuming a8a24f3f6e3810 Kirti Wankhede 2020-05-29 482 * |<---------| a8a24f3f6e3810 Kirti Wankhede 2020-05-29 483 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 484 * 5. Resumed a8a24f3f6e3810 Kirti Wankhede 2020-05-29 485 * |--------->| a8a24f3f6e3810 Kirti Wankhede 2020-05-29 486 * c12fa88c6d16ed Zenghui Yu 2020-09-10 487 * 0. Default state of VFIO device is _RUNNING when the user application starts. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 488 * 1. During normal shutdown of the user application, the user application may a8a24f3f6e3810 Kirti Wankhede 2020-05-29 489 * optionally change the VFIO device state from _RUNNING to _STOP. This a8a24f3f6e3810 Kirti Wankhede 2020-05-29 490 * transition is optional. The vendor driver must support this transition but a8a24f3f6e3810 Kirti Wankhede 2020-05-29 491 * must not require it. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 492 * 2. When the user application saves state or suspends the application, the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 493 * device state transitions from _RUNNING to stop-and-copy and then to _STOP. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 494 * On state transition from _RUNNING to stop-and-copy, driver must stop the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 495 * device, save the device state and send it to the application through the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 496 * migration region. The sequence to be followed for such transition is given a8a24f3f6e3810 Kirti Wankhede 2020-05-29 497 * below. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 498 * 3. In live migration of user application, the state transitions from _RUNNING a8a24f3f6e3810 Kirti Wankhede 2020-05-29 499 * to pre-copy, to stop-and-copy, and to _STOP. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 500 * On state transition from _RUNNING to pre-copy, the driver should start a8a24f3f6e3810 Kirti Wankhede 2020-05-29 501 * gathering the device state while the application is still running and send a8a24f3f6e3810 Kirti Wankhede 2020-05-29 502 * the device state data to application through the migration region. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 503 * On state transition from pre-copy to stop-and-copy, the driver must stop a8a24f3f6e3810 Kirti Wankhede 2020-05-29 504 * the device, save the device state and send it to the user application a8a24f3f6e3810 Kirti Wankhede 2020-05-29 505 * through the migration region. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 506 * Vendor drivers must support the pre-copy state even for implementations a8a24f3f6e3810 Kirti Wankhede 2020-05-29 507 * where no data is provided to the user before the stop-and-copy state. The a8a24f3f6e3810 Kirti Wankhede 2020-05-29 508 * user must not be required to consume all migration data before the device a8a24f3f6e3810 Kirti Wankhede 2020-05-29 509 * transitions to a new state, including the stop-and-copy state. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 510 * The sequence to be followed for above two transitions is given below. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 511 * 4. To start the resuming phase, the device state should be transitioned from a8a24f3f6e3810 Kirti Wankhede 2020-05-29 512 * the _RUNNING to the _RESUMING state. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 513 * In the _RESUMING state, the driver should use the device state data a8a24f3f6e3810 Kirti Wankhede 2020-05-29 514 * received through the migration region to resume the device. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 515 * 5. After providing saved device data to the driver, the application should a8a24f3f6e3810 Kirti Wankhede 2020-05-29 516 * change the state from _RESUMING to _RUNNING. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 517 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 518 * reserved: a8a24f3f6e3810 Kirti Wankhede 2020-05-29 519 * Reads on this field return zero and writes are ignored. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 520 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 521 * pending_bytes: (read only) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 522 * The number of pending bytes still to be migrated from the vendor driver. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 523 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 524 * data_offset: (read only) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 525 * The user application should read data_offset field from the migration a8a24f3f6e3810 Kirti Wankhede 2020-05-29 526 * region. The user application should read the device data from this a8a24f3f6e3810 Kirti Wankhede 2020-05-29 527 * offset within the migration region during the _SAVING state or write a8a24f3f6e3810 Kirti Wankhede 2020-05-29 528 * the device data during the _RESUMING state. See below for details of a8a24f3f6e3810 Kirti Wankhede 2020-05-29 529 * sequence to be followed. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 530 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 531 * data_size: (read/write) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 532 * The user application should read data_size to get the size in bytes of a8a24f3f6e3810 Kirti Wankhede 2020-05-29 533 * the data copied in the migration region during the _SAVING state and a8a24f3f6e3810 Kirti Wankhede 2020-05-29 534 * write the size in bytes of the data copied in the migration region a8a24f3f6e3810 Kirti Wankhede 2020-05-29 535 * during the _RESUMING state. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 536 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 537 * The format of the migration region is as follows: a8a24f3f6e3810 Kirti Wankhede 2020-05-29 538 * ------------------------------------------------------------------ a8a24f3f6e3810 Kirti Wankhede 2020-05-29 539 * |vfio_device_migration_info| data section | a8a24f3f6e3810 Kirti Wankhede 2020-05-29 540 * | | /////////////////////////////// | a8a24f3f6e3810 Kirti Wankhede 2020-05-29 541 * ------------------------------------------------------------------ a8a24f3f6e3810 Kirti Wankhede 2020-05-29 542 * ^ ^ a8a24f3f6e3810 Kirti Wankhede 2020-05-29 543 * offset 0-trapped part data_offset a8a24f3f6e3810 Kirti Wankhede 2020-05-29 544 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 545 * The structure vfio_device_migration_info is always followed by the data a8a24f3f6e3810 Kirti Wankhede 2020-05-29 546 * section in the region, so data_offset will always be nonzero. The offset a8a24f3f6e3810 Kirti Wankhede 2020-05-29 547 * from where the data is copied is decided by the kernel driver. The data a8a24f3f6e3810 Kirti Wankhede 2020-05-29 548 * section can be trapped, mmapped, or partitioned, depending on how the kernel a8a24f3f6e3810 Kirti Wankhede 2020-05-29 549 * driver defines the data section. The data section partition can be defined a8a24f3f6e3810 Kirti Wankhede 2020-05-29 550 * as mapped by the sparse mmap capability. If mmapped, data_offset must be a8a24f3f6e3810 Kirti Wankhede 2020-05-29 551 * page aligned, whereas initial section which contains the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 552 * vfio_device_migration_info structure, might not end at the offset, which is a8a24f3f6e3810 Kirti Wankhede 2020-05-29 553 * page aligned. The user is not required to access through mmap regardless a8a24f3f6e3810 Kirti Wankhede 2020-05-29 554 * of the capabilities of the region mmap. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 555 * The vendor driver should determine whether and how to partition the data a8a24f3f6e3810 Kirti Wankhede 2020-05-29 556 * section. The vendor driver should return data_offset accordingly. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 557 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 558 * The sequence to be followed while in pre-copy state and stop-and-copy state a8a24f3f6e3810 Kirti Wankhede 2020-05-29 559 * is as follows: a8a24f3f6e3810 Kirti Wankhede 2020-05-29 560 * a. Read pending_bytes, indicating the start of a new iteration to get device a8a24f3f6e3810 Kirti Wankhede 2020-05-29 561 * data. Repeated read on pending_bytes at this stage should have no side a8a24f3f6e3810 Kirti Wankhede 2020-05-29 562 * effects. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 563 * If pending_bytes == 0, the user application should not iterate to get data a8a24f3f6e3810 Kirti Wankhede 2020-05-29 564 * for that device. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 565 * If pending_bytes > 0, perform the following steps. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 566 * b. Read data_offset, indicating that the vendor driver should make data a8a24f3f6e3810 Kirti Wankhede 2020-05-29 567 * available through the data section. The vendor driver should return this a8a24f3f6e3810 Kirti Wankhede 2020-05-29 568 * read operation only after data is available from (region + data_offset) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 569 * to (region + data_offset + data_size). a8a24f3f6e3810 Kirti Wankhede 2020-05-29 570 * c. Read data_size, which is the amount of data in bytes available through a8a24f3f6e3810 Kirti Wankhede 2020-05-29 571 * the migration region. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 572 * Read on data_offset and data_size should return the offset and size of a8a24f3f6e3810 Kirti Wankhede 2020-05-29 573 * the current buffer if the user application reads data_offset and a8a24f3f6e3810 Kirti Wankhede 2020-05-29 574 * data_size more than once here. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 575 * d. Read data_size bytes of data from (region + data_offset) from the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 576 * migration region. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 577 * e. Process the data. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 578 * f. Read pending_bytes, which indicates that the data from the previous a8a24f3f6e3810 Kirti Wankhede 2020-05-29 579 * iteration has been read. If pending_bytes > 0, go to step b. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 580 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 581 * The user application can transition from the _SAVING|_RUNNING a8a24f3f6e3810 Kirti Wankhede 2020-05-29 582 * (pre-copy state) to the _SAVING (stop-and-copy) state regardless of the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 583 * number of pending bytes. The user application should iterate in _SAVING a8a24f3f6e3810 Kirti Wankhede 2020-05-29 584 * (stop-and-copy) until pending_bytes is 0. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 585 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 586 * The sequence to be followed while _RESUMING device state is as follows: a8a24f3f6e3810 Kirti Wankhede 2020-05-29 587 * While data for this device is available, repeat the following steps: a8a24f3f6e3810 Kirti Wankhede 2020-05-29 588 * a. Read data_offset from where the user application should write data. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 589 * b. Write migration data starting at the migration region + data_offset for a8a24f3f6e3810 Kirti Wankhede 2020-05-29 590 * the length determined by data_size from the migration source. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 591 * c. Write data_size, which indicates to the vendor driver that data is a8a24f3f6e3810 Kirti Wankhede 2020-05-29 592 * written in the migration region. Vendor driver must return this write a8a24f3f6e3810 Kirti Wankhede 2020-05-29 593 * operations on consuming data. Vendor driver should apply the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 594 * user-provided migration region data to the device resume state. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 595 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 596 * If an error occurs during the above sequences, the vendor driver can return a8a24f3f6e3810 Kirti Wankhede 2020-05-29 597 * an error code for next read() or write() operation, which will terminate the a8a24f3f6e3810 Kirti Wankhede 2020-05-29 598 * loop. The user application should then take the next necessary action, for a8a24f3f6e3810 Kirti Wankhede 2020-05-29 599 * example, failing migration or terminating the user application. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 600 * a8a24f3f6e3810 Kirti Wankhede 2020-05-29 601 * For the user application, data is opaque. The user application should write a8a24f3f6e3810 Kirti Wankhede 2020-05-29 602 * data in the same order as the data is received and the data should be of a8a24f3f6e3810 Kirti Wankhede 2020-05-29 603 * same transaction size at the source. a8a24f3f6e3810 Kirti Wankhede 2020-05-29 604 */ a8a24f3f6e3810 Kirti Wankhede 2020-05-29 605 a8a24f3f6e3810 Kirti Wankhede 2020-05-29 606 struct vfio_device_migration_info { a8a24f3f6e3810 Kirti Wankhede 2020-05-29 607 __u32 device_state; /* VFIO device state */ a8a24f3f6e3810 Kirti Wankhede 2020-05-29 @608 #define VFIO_DEVICE_STATE_STOP (0) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 609 #define VFIO_DEVICE_STATE_RUNNING (1 << 0) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 610 #define VFIO_DEVICE_STATE_SAVING (1 << 1) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 611 #define VFIO_DEVICE_STATE_RESUMING (1 << 2) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 612 #define VFIO_DEVICE_STATE_MASK (VFIO_DEVICE_STATE_RUNNING | \ a8a24f3f6e3810 Kirti Wankhede 2020-05-29 613 VFIO_DEVICE_STATE_SAVING | \ a8a24f3f6e3810 Kirti Wankhede 2020-05-29 614 VFIO_DEVICE_STATE_RESUMING) a8a24f3f6e3810 Kirti Wankhede 2020-05-29 615 :::::: The code at line 608 was first introduced by commit :::::: a8a24f3f6e38103b77cf399c38eb54e1219d00d6 vfio: UAPI for migration interface for device state :::::: TO: Kirti Wankhede <kwankhede(a)nvidia.com&gt; :::::: CC: Alex Williamson <alex.williamson(a)redhat.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org