diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/driver-api/vfio-mediated-device.rst | 108 | ||||
| -rw-r--r-- | Documentation/driver-api/vfio.rst | 82 | ||||
| -rw-r--r-- | Documentation/s390/vfio-ap.rst | 1 |
3 files changed, 61 insertions, 130 deletions
diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst index fdf7d69378ec..bbd548b66b42 100644 --- a/Documentation/driver-api/vfio-mediated-device.rst +++ b/Documentation/driver-api/vfio-mediated-device.rst @@ -60,7 +60,7 @@ devices as examples, as these devices are the first devices to use this module:: | mdev.ko | | +-----------+ | mdev_register_parent() +--------------+ | | | +<------------------------+ | - | | | | | nvidia.ko |<-> physical + | | | | | ccw_device.ko|<-> physical | | | +------------------------>+ | device | | | | callbacks +--------------+ | | Physical | | @@ -69,12 +69,6 @@ devices as examples, as these devices are the first devices to use this module:: | | | | | i915.ko |<-> physical | | | +------------------------>+ | device | | | | callbacks +--------------+ - | | | | - | | | | mdev_register_parent() +--------------+ - | | | +<------------------------+ | - | | | | | ccw_device.ko|<-> physical - | | | +------------------------>+ | device - | | | | callbacks +--------------+ | +-----------+ | +---------------+ @@ -270,106 +264,6 @@ these callbacks are supported in the TYPE1 IOMMU module. To enable them for other IOMMU backend modules, such as PPC64 sPAPR module, they need to provide these two callback functions. -Using the Sample Code -===================== - -mtty.c in samples/vfio-mdev/ directory is a sample driver program to -demonstrate how to use the mediated device framework. - -The sample driver creates an mdev device that simulates a serial port over a PCI -card. - -1. Build and load the mtty.ko module. - - This step creates a dummy device, /sys/devices/virtual/mtty/mtty/ - - Files in this device directory in sysfs are similar to the following:: - - # tree /sys/devices/virtual/mtty/mtty/ - /sys/devices/virtual/mtty/mtty/ - |-- mdev_supported_types - | |-- mtty-1 - | | |-- available_instances - | | |-- create - | | |-- device_api - | | |-- devices - | | `-- name - | `-- mtty-2 - | |-- available_instances - | |-- create - | |-- device_api - | |-- devices - | `-- name - |-- mtty_dev - | `-- sample_mtty_dev - |-- power - | |-- autosuspend_delay_ms - | |-- control - | |-- runtime_active_time - | |-- runtime_status - | `-- runtime_suspended_time - |-- subsystem -> ../../../../class/mtty - `-- uevent - -2. Create a mediated device by using the dummy device that you created in the - previous step:: - - # echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" > \ - /sys/devices/virtual/mtty/mtty/mdev_supported_types/mtty-2/create - -3. Add parameters to qemu-kvm:: - - -device vfio-pci,\ - sysfsdev=/sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001 - -4. Boot the VM. - - In the Linux guest VM, with no hardware on the host, the device appears - as follows:: - - # lspci -s 00:05.0 -xxvv - 00:05.0 Serial controller: Device 4348:3253 (rev 10) (prog-if 02 [16550]) - Subsystem: Device 4348:3253 - Physical Slot: 5 - Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- - Stepping- SERR- FastB2B- DisINTx- - Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- - <TAbort- <MAbort- >SERR- <PERR- INTx- - Interrupt: pin A routed to IRQ 10 - Region 0: I/O ports at c150 [size=8] - Region 1: I/O ports at c158 [size=8] - Kernel driver in use: serial - 00: 48 43 53 32 01 00 00 02 10 02 00 07 00 00 00 00 - 10: 51 c1 00 00 59 c1 00 00 00 00 00 00 00 00 00 00 - 20: 00 00 00 00 00 00 00 00 00 00 00 00 48 43 53 32 - 30: 00 00 00 00 00 00 00 00 00 00 00 00 0a 01 00 00 - - In the Linux guest VM, dmesg output for the device is as follows: - - serial 0000:00:05.0: PCI INT A -> Link[LNKA] -> GSI 10 (level, high) -> IRQ 10 - 0000:00:05.0: ttyS1 at I/O 0xc150 (irq = 10) is a 16550A - 0000:00:05.0: ttyS2 at I/O 0xc158 (irq = 10) is a 16550A - - -5. In the Linux guest VM, check the serial ports:: - - # setserial -g /dev/ttyS* - /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4 - /dev/ttyS1, UART: 16550A, Port: 0xc150, IRQ: 10 - /dev/ttyS2, UART: 16550A, Port: 0xc158, IRQ: 10 - -6. Using minicom or any terminal emulation program, open port /dev/ttyS1 or - /dev/ttyS2 with hardware flow control disabled. - -7. Type data on the minicom terminal or send data to the terminal emulation - program and read the data. - - Data is loop backed from hosts mtty driver. - -8. Destroy the mediated device that you created:: - - # echo 1 > /sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001/remove - References ========== diff --git a/Documentation/driver-api/vfio.rst b/Documentation/driver-api/vfio.rst index c663b6f97825..50b690f7f663 100644 --- a/Documentation/driver-api/vfio.rst +++ b/Documentation/driver-api/vfio.rst @@ -249,19 +249,21 @@ VFIO bus driver API VFIO bus drivers, such as vfio-pci make use of only a few interfaces into VFIO core. When devices are bound and unbound to the driver, -the driver should call vfio_register_group_dev() and -vfio_unregister_group_dev() respectively:: +Following interfaces are called when devices are bound to and +unbound from the driver:: - void vfio_init_group_dev(struct vfio_device *device, - struct device *dev, - const struct vfio_device_ops *ops); - void vfio_uninit_group_dev(struct vfio_device *device); int vfio_register_group_dev(struct vfio_device *device); + int vfio_register_emulated_iommu_dev(struct vfio_device *device); void vfio_unregister_group_dev(struct vfio_device *device); -The driver should embed the vfio_device in its own structure and call -vfio_init_group_dev() to pre-configure it before going to registration -and call vfio_uninit_group_dev() after completing the un-registration. +The driver should embed the vfio_device in its own structure and use +vfio_alloc_device() to allocate the structure, and can register +@init/@release callbacks to manage any private state wrapping the +vfio_device:: + + vfio_alloc_device(dev_struct, member, dev, ops); + void vfio_put_device(struct vfio_device *device); + vfio_register_group_dev() indicates to the core to begin tracking the iommu_group of the specified dev and register the dev as owned by a VFIO bus driver. Once vfio_register_group_dev() returns it is possible for userspace to @@ -270,28 +272,64 @@ ready before calling it. The driver provides an ops structure for callbacks similar to a file operations structure:: struct vfio_device_ops { - int (*open)(struct vfio_device *vdev); + char *name; + int (*init)(struct vfio_device *vdev); void (*release)(struct vfio_device *vdev); + int (*bind_iommufd)(struct vfio_device *vdev, + struct iommufd_ctx *ictx, u32 *out_device_id); + void (*unbind_iommufd)(struct vfio_device *vdev); + int (*attach_ioas)(struct vfio_device *vdev, u32 *pt_id); + int (*open_device)(struct vfio_device *vdev); + void (*close_device)(struct vfio_device *vdev); ssize_t (*read)(struct vfio_device *vdev, char __user *buf, size_t count, loff_t *ppos); - ssize_t (*write)(struct vfio_device *vdev, - const char __user *buf, - size_t size, loff_t *ppos); + ssize_t (*write)(struct vfio_device *vdev, const char __user *buf, + size_t count, loff_t *size); long (*ioctl)(struct vfio_device *vdev, unsigned int cmd, unsigned long arg); - int (*mmap)(struct vfio_device *vdev, - struct vm_area_struct *vma); + int (*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma); + void (*request)(struct vfio_device *vdev, unsigned int count); + int (*match)(struct vfio_device *vdev, char *buf); + void (*dma_unmap)(struct vfio_device *vdev, u64 iova, u64 length); + int (*device_feature)(struct vfio_device *device, u32 flags, + void __user *arg, size_t argsz); }; Each function is passed the vdev that was originally registered -in the vfio_register_group_dev() call above. This allows the bus driver -to obtain its private data using container_of(). The open/release -callbacks are issued when a new file descriptor is created for a -device (via VFIO_GROUP_GET_DEVICE_FD). The ioctl interface provides -a direct pass through for VFIO_DEVICE_* ioctls. The read/write/mmap -interfaces implement the device region access defined by the device's -own VFIO_DEVICE_GET_REGION_INFO ioctl. +in the vfio_register_group_dev() or vfio_register_emulated_iommu_dev() +call above. This allows the bus driver to obtain its private data using +container_of(). + +:: + + - The init/release callbacks are issued when vfio_device is initialized + and released. + + - The open/close device callbacks are issued when the first + instance of a file descriptor for the device is created (eg. + via VFIO_GROUP_GET_DEVICE_FD) for a user session. + + - The ioctl callback provides a direct pass through for some VFIO_DEVICE_* + ioctls. + + - The [un]bind_iommufd callbacks are issued when the device is bound to + and unbound from iommufd. + + - The attach_ioas callback is issued when the device is attached to an + IOAS managed by the bound iommufd. The attached IOAS is automatically + detached when the device is unbound from iommufd. + + - The read/write/mmap callbacks implement the device region access defined + by the device's own VFIO_DEVICE_GET_REGION_INFO ioctl. + + - The request callback is issued when device is going to be unregistered, + such as when trying to unbind the device from the vfio bus driver. + - The dma_unmap callback is issued when a range of iovas are unmapped + in the container or IOAS attached by the device. Drivers which make + use of the vfio page pinning interface must implement this callback in + order to unpin pages within the dma_unmap range. Drivers must tolerate + this callback even before calls to open_device(). PPC64 sPAPR implementation note ------------------------------- diff --git a/Documentation/s390/vfio-ap.rst b/Documentation/s390/vfio-ap.rst index 00f4a04f6d4c..d46e98c7c1ec 100644 --- a/Documentation/s390/vfio-ap.rst +++ b/Documentation/s390/vfio-ap.rst @@ -553,7 +553,6 @@ These are the steps: * ZCRYPT * S390_AP_IOMMU * VFIO - * VFIO_MDEV * KVM If using make menuconfig select the following to build the vfio_ap module:: |