概述
《ARM SMMU原理与IOMMU技术（“VT-d” DMA、I/O虚拟化、内存虚拟化）》
《提升KVM异构虚拟机启动效率：透传(pass-through)、DMA映射（VFIO、PCI、IOMMU）、virtio-balloon、异步DMA映射、预处理》
《内核引导参数IOMMU与INTEL_IOMMU有何不同？》
《DMAR（DMA remapping）与 IOMMU》
《Linux驱动：VFIO概述(vfio/iommu/device passthrough)》
《Linux内核：VFIO 内核文档 (翻译)》
目录
Groups、Devices和IOMMUs
VFIO使用实例
VFIO API
VFIO bus驱动API
本文是VFIO内核文档[1]的翻译。
很多现代系统提供DMA和中断重映射工具来帮助保证IO在被指定的界限中进行。包括x86硬件的AMD-Vi和Intel VT-d，POWER系统的Partitionable Endpoints (PEs)和嵌入式的PowerPC系统(如Freescale PAMU)。VFIO driver是IOMMU/设备不可知的一个框架，它只是专门用于将设备在安全的、IOMMU保护的环境下直接暴露给userspace。换句话说，VFIO允许安全且非特权的用户态驱动。
我们为什么需要VFIO？一个原因是虚拟机经常时用直接设备访问(“device assignment”)来获得尽可能高的IO性能。从设备和host的角度，这其实就是把VM变成了一个用户态驱动，VM也因此获得了这个IO设备的低延迟、高带宽和全虚拟化原生(bare-metal)设备驱动的直接应用。
一些应用场景中(特别是这高性能计算领域)，也会从低开销的从用户空间的直接设备访问获得好处。例子包括网卡(通常基于非TCP/IP)和计算加速器等IO设备。在VFIO之前，这些驱动必须经过很长的开发周期来成为上游驱动、单独分支维护，或者使用UIO框架(UIO并不支持IOMMU保护，并且对中断支持有限，还需要root权限来访问PCI配置空间等东西)。
VFIO驱动框架用来将所有东西统一起来，代替KVM PCI设备assignment的代码，并提供一个比UIO更安全、功能更丰富的用户态驱动环境。
Groups、Devices和IOMMUs
设备是任何IO驱动的主要目标。设备一般会创建包括IO访问、中断和DMA在内的编程接口。不讨论每个驱动的细节，DMA通常是保证安全环境的最重要的部分，这是由于如果不对设备向物理内存的读写操作不设限制，将会造成对整个系统造成极大威胁。
为了减小这种风险，很多现代IOMMU将隔离特性加入到负责地址转换的接口中，这解决了设备在受限制的地址空间的寻址问题。有了这种介质，设备之间或者设备和某块内存间可以实现有效的隔离，这也允许了设备到虚拟机的安全直接管理。
这种隔离性的粒度并不总是单个设备，即使IOMMU可以做到这点，设备的属性、连接方式和IOMMU拓扑结构都可能会减弱这种隔离性。比如，一个独立的设备可能是一个更大范围设备集合的子集，那么即使IOMMU可以辨识出在这一集合中的不同设备，这个集合中的transactions也不会需要经过IOMMU。例如，从一个functions之间有后门的多function PCI设备，到一个non-PCI-ACS (Access Control Services)bridge的任何东西都允许不经过IOMMU的重定向。拓扑结构也在隐藏设备这件事中扮演着很重要的角色。一个PCIe-to-PCI的bridge隐藏了它之后的所有设备，让transaction看起来就来自bridge本身。显然，IOMMU也承担了主要的任务。
因此，虽然大多数情况下IOMMU可以达到设备级的隔离粒度，系统一般也是容忍这个粒度被放宽的。IOMMU API也因此支持IOMMU group的概念。一个group就是一组设备的集合，这组设备隔离于系统的其他设备。Group因此也是VFIO所用的ownership的单元。
虽然group是保证用户访问安全的最小粒度，它并不一定是最好的粒度。在使用page tables的IOMMU中，多个groups之间共享一组page table是可能的，这减小了硬件平台的开销(减少TLB thrashing、减少重复page table等)，也减小了用户的开销(只编写一个set的转换即可)。因此，VFIO使用了一个container的概念，一个class可以包括一个或者多个groups。创建一个container很简单，只要打开/dev/vfio/vfio字符设备即可。
Container自身只提供很少的功能，。。。 用户需要将group加到container中来获得下一级的功能。要这样做，用户首先需要找到所关心设备所属的group，这可以用下边例子中的sysfs链接办到。通过将设备从host驱动解绑并绑定到VFIO驱动上，一个新的VFIO group会出现为/dev/vfio/$GROUP，其中$GROUP是IOMMU的group number，目标的设备是这个group的成员。如果IOMMU group有多个设备，那么这个VFIO group可用前，每个设备都需要绑定到一个VFIO驱动上(只是将所有设备从host驱动解绑也可以，这也会让group可用，但是没有绑定VFIO设备的特定设备不可用)。待定：禁用驱动probing/locking一个设备的接口。
如果group准备好了，可以通过open这个VFIO group字符设备(/dev/vfio/$GROUP)将这个group加入到container中，并用ioctl的VFIO_GROUP_SET_CONTAINER参数将打开的container文件描述符fd传入。如果需要在多个group间分享IOMMU上下文中，过个group可以被设置(set)到一个相同的container。如果一个group无法被set到一个container，那么一个空的container将被使用。
如果一个或多个group被加入到一个container，那么剩下的ioctl参数就可用了，可以访问VFIO IOMMU接口了。而且，现在在VFIO group的fd上用ioctl可以得到每个设备的文件描述符。
VFIO设备的API包括描述设备、描述IO region、描述设备描述符上read/write/mmap偏移量的ioctl参数，也包括描述和注册中断通知的机制。
VFIO使用实例
假如我们想访问PCI设备0000:06:0d.0：
$ readlink /sys/bus/pci/devices/0000:06:0d.0/iommu_group
../../../../kernel/iommu_groups/26
因此这个设备在IOMMU group 26。这个设备在pci bus上，所以用户会用vfio-pci管理这个组：
# modprobe vfio-pci绑定这个设备到vfio-pci驱动并为这个group创建VFIO group字符设备：
$ lspci -n -s 0000:06:0d.0
06:0d.0 0401: 1102:0002 (rev 08)
# echo 0000:06:0d.0 > /sys/bus/pci/devices/0000:06:0d.0/driver/unbind
# echo 1102 0002 > /sys/bus/pci/drivers/vfio-pci/new_id
现在我们需要看下group中的其他设备并且释放他们以使用VFIO：
$ ls -l /sys/bus/pci/devices/0000:06:0d.0/iommu_group/devices
total 0
lrwxrwxrwx. 1 root root 0 Apr 23 16:13 0000:00:1e.0 ->
../../../../devices/pci0000:00/0000:00:1e.0
lrwxrwxrwx. 1 root root 0 Apr 23 16:13 0000:06:0d.0 ->
../../../../devices/pci0000:00/0000:00:1e.0/0000:06:0d.0
lrwxrwxrwx. 1 root root 0 Apr 23 16:13 0000:06:0d.1 ->
../../../../devices/pci0000:00/0000:00:1e.0/0000:06:0d.1
这个设备在PCIe-to-PCI桥后，因此我们也需要根据以前的步骤增加设备0000:06:0d.1到组中。设备0000:00:1e.0是一个当前没有host driver的bridge，所以不要将这个设备绑定到vfio-pci驱动 (vfio-pci当前不支持PCI桥)。
最后一步是，如果非特权操作被需要，给用户到group的访问权限，(注意/dev/vfio/vfio自身并没有这个能力，所以需要被系统设置为0666权限)：
# chown user:user /dev/vfio/26
现在用户可以访问所有设备和这个group的IOMMU了：
int container, group, device, i;
struct vfio_group_status group_status =
{ .argsz = sizeof(group_status) };
struct vfio_iommu_type1_info iommu_info = { .argsz = sizeof(iommu_info) };
struct vfio_iommu_type1_dma_map dma_map = { .argsz = sizeof(dma_map) };
struct vfio_device_info device_info = { .argsz = sizeof(device_info) };
/* Create a new container */
container = open("/dev/vfio/vfio", O_RDWR);
if (ioctl(container, VFIO_GET_API_VERSION) != VFIO_API_VERSION)
/* Unknown API version */
if (!ioctl(container, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU))
/* Doesn't support the IOMMU driver we want. */
/* Open the group */
group = open("/dev/vfio/26", O_RDWR);
/* Test the group is viable and available */
ioctl(group, VFIO_GROUP_GET_STATUS, &group_status);
if (!(group_status.flags & VFIO_GROUP_FLAGS_VIABLE))
/* Group is not viable (ie, not all devices bound for vfio) */
/* Add the group to the container */
ioctl(group, VFIO_GROUP_SET_CONTAINER, &container);
/* Enable the IOMMU model we want */
ioctl(container, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU);
/* Get addition IOMMU info */
ioctl(container, VFIO_IOMMU_GET_INFO, &iommu_info);
/* Allocate some space and setup a DMA mapping */
dma_map.vaddr = mmap(0, 1024 * 1024, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
dma_map.size = 1024 * 1024;
dma_map.iova = 0; /* 1MB starting at 0x0 from device view */
dma_map.flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
ioctl(container, VFIO_IOMMU_MAP_DMA, &dma_map);
/* Get a file descriptor for the device */
device = ioctl(group, VFIO_GROUP_GET_DEVICE_FD, "0000:06:0d.0");
/* Test and setup the device */
ioctl(device, VFIO_DEVICE_GET_INFO, &device_info);
for (i = 0; i < device_info.num_regions; i++) {
struct vfio_region_info reg = { .argsz = sizeof(reg) };
reg.index = i;
ioctl(device, VFIO_DEVICE_GET_REGION_INFO, ®);
/* Setup mappings... read/write offsets, mmaps
* For PCI devices, config space is a region */
}
for (i = 0; i < device_info.num_irqs; i++) {
struct vfio_irq_info irq = { .argsz = sizeof(irq) };
irq.index = i;
ioctl(device, VFIO_DEVICE_GET_IRQ_INFO, &irq);
/* Setup IRQs... eventfds, VFIO_DEVICE_SET_IRQS */
}
/* Gratuitous device reset and go... */
ioctl(device, VFIO_DEVICE_RESET);
VFIO API
API的详细文档，请看include/linux/vfio.h[2] 和include/uapi/linux/vfio.h[3]。前者是内核态API，后者是用户态API。
VFIO bus驱动API
VFIO bus driver，比如vfio-pci只用几个接口来与VFIO core交互。驱动会调用vfio_add_group_dev()或者vfio_del_group_dev()来bound或者unbound到驱动：
extern int vfio_add_group_dev(struct device *dev,
const struct vfio_device_ops *ops,
void *device_data);
extern void *vfio_del_group_dev(struct device *dev);
vfio_add_group_dev()让VFIO core去开始追踪一个特定dev的iommu_group并将这个dev注册为一个VFIO bus driver。这个driver提供一个ops结构来提供类似file operations的回调结构：
struct vfio_device_ops {
int (*open)(void *device_data);
void (*release)(void *device_data);
ssize_t (*read)(void *device_data, char __user *buf, size_t count, loff_t *ppos);
ssize_t (*write)(void *device_data, const char __user *buf, size_t size, loff_t *ppos);
long (*ioctl)(void *device_data, unsigned int cmd, unsigned long arg);
int (*mmap)(void *device_data, struct vm_area_struct *vma);
};
以vfio-pci这个bus驱动(drivers/vfio/pci/vfio_pci.c)为例：
static const struct vfio_device_ops vfio_pci_ops = {
.name = "vfio-pci",
.open = vfio_pci_open,
.release = vfio_pci_release,
.ioctl = vfio_pci_ioctl,
.read = vfio_pci_read,
.write = vfio_pci_write,
.mmap = vfio_pci_mmap,
.request = vfio_pci_request,
};
每个函数都被传入在vfio_add_group_dev()中注册过的device_data。这允许bus driver成为容易存储opaque、私有数据的地方。当为一个设备一个新的fd被创建时，open/release回调函数将被调用(用VFIO_GROUP_GET_DEVICE_FD)。ioctl接口为 VFIO_DEVICE_xxx这些参数提供直接的passthrough。read/write/mmap这些接口实现设备自己VFIO_DEVICE_GET_REGION_INFO这个ioctl定义的region的访问。
- [1] https://github.com/torvalds/linux/blob/master/Documentation/vfio.txt
- [2] https://github.com/torvalds/linux/blob/master/include/linux/vfio.h
- [3] https://github.com/torvalds/linux/blob/master/include/uapi/linux/vfio.h
https://github.com/torvalds/linux/edit/master/include/uapi/linux/vfio.h：内容如下：
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
* VFIO API definition
*
* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
* Author: Alex Williamson <alex.williamson@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef _UAPIVFIO_H
#define _UAPIVFIO_H
#include <linux/types.h>
#include <linux/ioctl.h>
#define VFIO_API_VERSION 0
/* Kernel & User level defines for VFIO IOCTLs. */
/* Extensions */
#define VFIO_TYPE1_IOMMU 1
#define VFIO_SPAPR_TCE_IOMMU 2
#define VFIO_TYPE1v2_IOMMU 3
/*
* IOMMU enforces DMA cache coherence (ex. PCIe NoSnoop stripping). This
* capability is subject to change as groups are added or removed.
*/
#define VFIO_DMA_CC_IOMMU 4
/* Check if EEH is supported */
#define VFIO_EEH 5
/* Two-stage IOMMU */
#define VFIO_TYPE1_NESTING_IOMMU 6 /* Implies v2 */
#define VFIO_SPAPR_TCE_v2_IOMMU 7
/*
* The No-IOMMU IOMMU offers no translation or isolation for devices and
* supports no ioctls outside of VFIO_CHECK_EXTENSION. Use of VFIO's No-IOMMU
* code will taint the host kernel and should be used with extreme caution.
*/
#define VFIO_NOIOMMU_IOMMU 8
/*
* The IOCTL interface is designed for extensibility by embedding the
* structure length (argsz) and flags into structures passed between
* kernel and userspace. We therefore use the _IO() macro for these
* defines to avoid implicitly embedding a size into the ioctl request.
* As structure fields are added, argsz will increase to match and flag
* bits will be defined to indicate additional fields with valid data.
* It's *always* the caller's responsibility to indicate the size of
* the structure passed by setting argsz appropriately.
*/
#define VFIO_TYPE (';')
#define VFIO_BASE 100
/*
* For extension of INFO ioctls, VFIO makes use of a capability chain
* designed after PCI/e capabilities. A flag bit indicates whether
* this capability chain is supported and a field defined in the fixed
* structure defines the offset of the first capability in the chain.
* This field is only valid when the corresponding bit in the flags
* bitmap is set. This offset field is relative to the start of the
* INFO buffer, as is the next field within each capability header.
* The id within the header is a shared address space per INFO ioctl,
* while the version field is specific to the capability id. The
* contents following the header are specific to the capability id.
*/
struct vfio_info_cap_header {
__u16 id; /* Identifies capability */
__u16 version; /* Version specific to the capability ID */
__u32 next; /* Offset of next capability */
};
/*
* Callers of INFO ioctls passing insufficiently sized buffers will see
* the capability chain flag bit set, a zero value for the first capability
* offset (if available within the provided argsz), and argsz will be
* updated to report the necessary buffer size. For compatibility, the
* INFO ioctl will not report error in this case, but the capability chain
* will not be available.
*/
/* -------- IOCTLs for VFIO file descriptor (/dev/vfio/vfio) -------- */
/**
* VFIO_GET_API_VERSION - _IO(VFIO_TYPE, VFIO_BASE + 0)
*
* Report the version of the VFIO API. This allows us to bump the entire
* API version should we later need to add or change features in incompatible
* ways.
* Return: VFIO_API_VERSION
* Availability: Always
*/
#define VFIO_GET_API_VERSION _IO(VFIO_TYPE, VFIO_BASE + 0)
/**
* VFIO_CHECK_EXTENSION - _IOW(VFIO_TYPE, VFIO_BASE + 1, __u32)
*
* Check whether an extension is supported.
* Return: 0 if not supported, 1 (or some other positive integer) if supported.
* Availability: Always
*/
#define VFIO_CHECK_EXTENSION _IO(VFIO_TYPE, VFIO_BASE + 1)
/**
* VFIO_SET_IOMMU - _IOW(VFIO_TYPE, VFIO_BASE + 2, __s32)
*
* Set the iommu to the given type. The type must be supported by an
* iommu driver as verified by calling CHECK_EXTENSION using the same
* type. A group must be set to this file descriptor before this
* ioctl is available. The IOMMU interfaces enabled by this call are
* specific to the value set.
* Return: 0 on success, -errno on failure
* Availability: When VFIO group attached
*/
#define VFIO_SET_IOMMU _IO(VFIO_TYPE, VFIO_BASE + 2)
/* -------- IOCTLs for GROUP file descriptors (/dev/vfio/$GROUP) -------- */
/**
* VFIO_GROUP_GET_STATUS - _IOR(VFIO_TYPE, VFIO_BASE + 3,
* struct vfio_group_status)
*
* Retrieve information about the group. Fills in provided
* struct vfio_group_info. Caller sets argsz.
* Return: 0 on succes, -errno on failure.
* Availability: Always
*/
struct vfio_group_status {
__u32 argsz;
__u32 flags;
#define VFIO_GROUP_FLAGS_VIABLE (1 << 0)
#define VFIO_GROUP_FLAGS_CONTAINER_SET (1 << 1)
};
#define VFIO_GROUP_GET_STATUS _IO(VFIO_TYPE, VFIO_BASE + 3)
/**
* VFIO_GROUP_SET_CONTAINER - _IOW(VFIO_TYPE, VFIO_BASE + 4, __s32)
*
* Set the container for the VFIO group to the open VFIO file
* descriptor provided. Groups may only belong to a single
* container. Containers may, at their discretion, support multiple
* groups. Only when a container is set are all of the interfaces
* of the VFIO file descriptor and the VFIO group file descriptor
* available to the user.
* Return: 0 on success, -errno on failure.
* Availability: Always
*/
#define VFIO_GROUP_SET_CONTAINER _IO(VFIO_TYPE, VFIO_BASE + 4)
/**
* VFIO_GROUP_UNSET_CONTAINER - _IO(VFIO_TYPE, VFIO_BASE + 5)
*
* Remove the group from the attached container. This is the
* opposite of the SET_CONTAINER call and returns the group to
* an initial state. All device file descriptors must be released
* prior to calling this interface. When removing the last group
* from a container, the IOMMU will be disabled and all state lost,
* effectively also returning the VFIO file descriptor to an initial
* state.
* Return: 0 on success, -errno on failure.
* Availability: When attached to container
*/
#define VFIO_GROUP_UNSET_CONTAINER _IO(VFIO_TYPE, VFIO_BASE + 5)
/**
* VFIO_GROUP_GET_DEVICE_FD - _IOW(VFIO_TYPE, VFIO_BASE + 6, char)
*
* Return a new file descriptor for the device object described by
* the provided string. The string should match a device listed in
* the devices subdirectory of the IOMMU group sysfs entry. The
* group containing the device must already be added to this context.
* Return: new file descriptor on success, -errno on failure.
* Availability: When attached to container
*/
#define VFIO_GROUP_GET_DEVICE_FD _IO(VFIO_TYPE, VFIO_BASE + 6)
/* --------------- IOCTLs for DEVICE file descriptors --------------- */
/**
* VFIO_DEVICE_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 7,
* struct vfio_device_info)
*
* Retrieve information about the device. Fills in provided
* struct vfio_device_info. Caller sets argsz.
* Return: 0 on success, -errno on failure.
*/
struct vfio_device_info {
__u32 argsz;
__u32 flags;
#define VFIO_DEVICE_FLAGS_RESET (1 << 0) /* Device supports reset */
#define VFIO_DEVICE_FLAGS_PCI (1 << 1) /* vfio-pci device */
#define VFIO_DEVICE_FLAGS_PLATFORM (1 << 2) /* vfio-platform device */
#define VFIO_DEVICE_FLAGS_AMBA (1 << 3) /* vfio-amba device */
#define VFIO_DEVICE_FLAGS_CCW (1 << 4) /* vfio-ccw device */
#define VFIO_DEVICE_FLAGS_AP (1 << 5) /* vfio-ap device */
#define VFIO_DEVICE_FLAGS_FSL_MC (1 << 6) /* vfio-fsl-mc device */
#define VFIO_DEVICE_FLAGS_CAPS (1 << 7) /* Info supports caps */
__u32 num_regions; /* Max region index + 1 */
__u32 num_irqs; /* Max IRQ index + 1 */
__u32 cap_offset; /* Offset within info struct of first cap */
};
#define VFIO_DEVICE_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 7)
/*
* Vendor driver using Mediated device framework should provide device_api
* attribute in supported type attribute groups. Device API string should be one
* of the following corresponding to device flags in vfio_device_info structure.
*/
#define VFIO_DEVICE_API_PCI_STRING "vfio-pci"
#define VFIO_DEVICE_API_PLATFORM_STRING "vfio-platform"
#define VFIO_DEVICE_API_AMBA_STRING "vfio-amba"
#define VFIO_DEVICE_API_CCW_STRING "vfio-ccw"
#define VFIO_DEVICE_API_AP_STRING "vfio-ap"
/*
* The following capabilities are unique to s390 zPCI devices. Their contents
* are further-defined in vfio_zdev.h
*/
#define VFIO_DEVICE_INFO_CAP_ZPCI_BASE 1
#define VFIO_DEVICE_INFO_CAP_ZPCI_GROUP 2
#define VFIO_DEVICE_INFO_CAP_ZPCI_UTIL 3
#define VFIO_DEVICE_INFO_CAP_ZPCI_PFIP 4
/**
* VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 8,
* struct vfio_region_info)
*
* Retrieve information about a device region. Caller provides
* struct vfio_region_info with index value set. Caller sets argsz.
* Implementation of region mapping is bus driver specific. This is
* intended to describe MMIO, I/O port, as well as bus specific
* regions (ex. PCI config space). Zero sized regions may be used
* to describe unimplemented regions (ex. unimplemented PCI BARs).
* Return: 0 on success, -errno on failure.
*/
struct vfio_region_info {
__u32 argsz;
__u32 flags;
#define VFIO_REGION_INFO_FLAG_READ (1 << 0) /* Region supports read */
#define VFIO_REGION_INFO_FLAG_WRITE (1 << 1) /* Region supports write */
#define VFIO_REGION_INFO_FLAG_MMAP (1 << 2) /* Region supports mmap */
#define VFIO_REGION_INFO_FLAG_CAPS (1 << 3) /* Info supports caps */
__u32 index; /* Region index */
__u32 cap_offset; /* Offset within info struct of first cap */
__u64 size; /* Region size (bytes) */
__u64 offset; /* Region offset from start of device fd */
};
#define VFIO_DEVICE_GET_REGION_INFO _IO(VFIO_TYPE, VFIO_BASE + 8)
/*
* The sparse mmap capability allows finer granularity of specifying areas
* within a region with mmap support. When specified, the user should only
* mmap the offset ranges specified by the areas array. mmaps outside of the
* areas specified may fail (such as the range covering a PCI MSI-X table) or
* may result in improper device behavior.
*
* The structures below define version 1 of this capability.
*/
#define VFIO_REGION_INFO_CAP_SPARSE_MMAP 1
struct vfio_region_sparse_mmap_area {
__u64 offset; /* Offset of mmap'able area within region */
__u64 size; /* Size of mmap'able area */
};
struct vfio_region_info_cap_sparse_mmap {
struct vfio_info_cap_header header;
__u32 nr_areas;
__u32 reserved;
struct vfio_region_sparse_mmap_area areas[];
};
/*
* The device specific type capability allows regions unique to a specific
* device or class of devices to be exposed. This helps solve the problem for
* vfio bus drivers of defining which region indexes correspond to which region
* on the device, without needing to resort to static indexes, as done by
* vfio-pci. For instance, if we were to go back in time, we might remove
* VFIO_PCI_VGA_REGION_INDEX and let vfio-pci simply define that all indexes
* greater than or equal to VFIO_PCI_NUM_REGIONS are device specific and we'd
* make a "VGA" device specific type to describe the VGA access space. This
* means that non-VGA devices wouldn't need to waste this index, and thus the
* address space associated with it due to implementation of device file
* descriptor offsets in vfio-pci.
*
* The current implementation is now part of the user ABI, so we can't use this
* for VGA, but there are other upcoming use cases, such as opregions for Intel
* IGD devices and framebuffers for vGPU devices. We missed VGA, but we'll
* use this for future additions.
*
* The structure below defines version 1 of this capability.
*/
#define VFIO_REGION_INFO_CAP_TYPE 2
struct vfio_region_info_cap_type {
struct vfio_info_cap_header header;
__u32 type; /* global per bus driver */
__u32 subtype; /* type specific */
};
/*
* List of region types, global per bus driver.
* If you introduce a new type, please add it here.
*/
/* PCI region type containing a PCI vendor part */
#define VFIO_REGION_TYPE_PCI_VENDOR_TYPE (1 << 31)
#define VFIO_REGION_TYPE_PCI_VENDOR_MASK (0xffff)
#define VFIO_REGION_TYPE_GFX (1)
#define VFIO_REGION_TYPE_CCW (2)
#define VFIO_REGION_TYPE_MIGRATION (3)
/* sub-types for VFIO_REGION_TYPE_PCI_* */
/* 8086 vendor PCI sub-types */
#define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION (1)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2)
#define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3)
/* 10de vendor PCI sub-types */
/*
* NVIDIA GPU NVlink2 RAM is coherent RAM mapped onto the host address space.
*/
#define VFIO_REGION_SUBTYPE_NVIDIA_NVLINK2_RAM (1)
/* 1014 vendor PCI sub-types */
/*
* IBM NPU NVlink2 ATSD (Address Translation Shootdown) register of NPU
* to do TLB invalidation on a GPU.
*/
#define VFIO_REGION_SUBTYPE_IBM_NVLINK2_ATSD (1)
/* sub-types for VFIO_REGION_TYPE_GFX */
#define VFIO_REGION_SUBTYPE_GFX_EDID (1)
/**
* struct vfio_region_gfx_edid - EDID region layout.
*
* Set display link state and EDID blob.
*
* The EDID blob has monitor information such as brand, name, serial
* number, physical size, supported video modes and more.
*
* This special region allows userspace (typically qemu) set a virtual
* EDID for the virtual monitor, which allows a flexible display
* configuration.
*
* For the edid blob spec look here:
* https://en.wikipedia.org/wiki/Extended_Display_Identification_Data
*
* On linux systems you can find the EDID blob in sysfs:
* /sys/class/drm/${card}/${connector}/edid
*
* You can use the edid-decode ulility (comes with xorg-x11-utils) to
* decode the EDID blob.
*
* @edid_offset: location of the edid blob, relative to the
* start of the region (readonly).
* @edid_max_size: max size of the edid blob (readonly).
* @edid_size: actual edid size (read/write).
* @link_state: display link state (read/write).
* VFIO_DEVICE_GFX_LINK_STATE_UP: Monitor is turned on.
* VFIO_DEVICE_GFX_LINK_STATE_DOWN: Monitor is turned off.
* @max_xres: max display width (0 == no limitation, readonly).
* @max_yres: max display height (0 == no limitation, readonly).
*
* EDID update protocol:
* (1) set link-state to down.
* (2) update edid blob and size.
* (3) set link-state to up.
*/
struct vfio_region_gfx_edid {
__u32 edid_offset;
__u32 edid_max_size;
__u32 edid_size;
__u32 max_xres;
__u32 max_yres;
__u32 link_state;
#define VFIO_DEVICE_GFX_LINK_STATE_UP 1
#define VFIO_DEVICE_GFX_LINK_STATE_DOWN 2
};
/* sub-types for VFIO_REGION_TYPE_CCW */
#define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1)
#define VFIO_REGION_SUBTYPE_CCW_SCHIB (2)
#define VFIO_REGION_SUBTYPE_CCW_CRW (3)
/* sub-types for VFIO_REGION_TYPE_MIGRATION */
#define VFIO_REGION_SUBTYPE_MIGRATION (1)
/*
* The structure vfio_device_migration_info is placed at the 0th offset of
* the VFIO_REGION_SUBTYPE_MIGRATION region to get and set VFIO device related
* migration information. Field accesses from this structure are only supported
* at their native width and alignment. Otherwise, the result is undefined and
* vendor drivers should return an error.
*
* device_state: (read/write)
* - The user application writes to this field to inform the vendor driver
* about the device state to be transitioned to.
* - The vendor driver should take the necessary actions to change the
* device state. After successful transition to a given state, the
* vendor driver should return success on write(device_state, state)
* system call. If the device state transition fails, the vendor driver
* should return an appropriate -errno for the fault condition.
* - On the user application side, if the device state transition fails,
* that is, if write(device_state, state) returns an error, read
* device_state again to determine the current state of the device from
* the vendor driver.
* - The vendor driver should return previous state of the device unless
* the vendor driver has encountered an internal error, in which case
* the vendor driver may report the device_state VFIO_DEVICE_STATE_ERROR.
* - The user application must use the device reset ioctl to recover the
* device from VFIO_DEVICE_STATE_ERROR state. If the device is
* indicated to be in a valid device state by reading device_state, the
* user application may attempt to transition the device to any valid
* state reachable from the current state or terminate itself.
*
* device_state consists of 3 bits:
* - If bit 0 is set, it indicates the _RUNNING state. If bit 0 is clear,
* it indicates the _STOP state. When the device state is changed to
* _STOP, driver should stop the device before write() returns.
* - If bit 1 is set, it indicates the _SAVING state, which means that the
* driver should start gathering device state information that will be
* provided to the VFIO user application to save the device's state.
* - If bit 2 is set, it indicates the _RESUMING state, which means that
* the driver should prepare to resume the device. Data provided through
* the migration region should be used to resume the device.
* Bits 3 - 31 are reserved for future use. To preserve them, the user
* application should perform a read-modify-write operation on this
* field when modifying the specified bits.
*
* +------- _RESUMING
* |+------ _SAVING
* ||+----- _RUNNING
* |||
* 000b => Device Stopped, not saving or resuming
* 001b => Device running, which is the default state
* 010b => Stop the device & save the device state, stop-and-copy state
* 011b => Device running and save the device state, pre-copy state
* 100b => Device stopped and the device state is resuming
* 101b => Invalid state
* 110b => Error state
* 111b => Invalid state
*
* State transitions:
*
* _RESUMING _RUNNING Pre-copy Stop-and-copy _STOP
* (100b) (001b) (011b) (010b) (000b)
* 0. Running or default state
* |
*
* 1. Normal Shutdown (optional)
* |------------------------------------->|
*
* 2. Save the state or suspend
* |------------------------->|---------->|
*
* 3. Save the state during live migration
* |----------->|------------>|---------->|
*
* 4. Resuming
* |<---------|
*
* 5. Resumed
* |--------->|
*
* 0. Default state of VFIO device is _RUNNING when the user application starts.
* 1. During normal shutdown of the user application, the user application may
* optionally change the VFIO device state from _RUNNING to _STOP. This
* transition is optional. The vendor driver must support this transition but
* must not require it.
* 2. When the user application saves state or suspends the application, the
* device state transitions from _RUNNING to stop-and-copy and then to _STOP.
* On state transition from _RUNNING to stop-and-copy, driver must stop the
* device, save the device state and send it to the application through the
* migration region. The sequence to be followed for such transition is given
* below.
* 3. In live migration of user application, the state transitions from _RUNNING
* to pre-copy, to stop-and-copy, and to _STOP.
* On state transition from _RUNNING to pre-copy, the driver should start
* gathering the device state while the application is still running and send
* the device state data to application through the migration region.
* On state transition from pre-copy to stop-and-copy, the driver must stop
* the device, save the device state and send it to the user application
* through the migration region.
* Vendor drivers must support the pre-copy state even for implementations
* where no data is provided to the user before the stop-and-copy state. The
* user must not be required to consume all migration data before the device
* transitions to a new state, including the stop-and-copy state.
* The sequence to be followed for above two transitions is given below.
* 4. To start the resuming phase, the device state should be transitioned from
* the _RUNNING to the _RESUMING state.
* In the _RESUMING state, the driver should use the device state data
* received through the migration region to resume the device.
* 5. After providing saved device data to the driver, the application should
* change the state from _RESUMING to _RUNNING.
*
* reserved:
* Reads on this field return zero and writes are ignored.
*
* pending_bytes: (read only)
* The number of pending bytes still to be migrated from the vendor driver.
*
* data_offset: (read only)
* The user application should read data_offset field from the migration
* region. The user application should read the device data from this
* offset within the migration region during the _SAVING state or write
* the device data during the _RESUMING state. See below for details of
* sequence to be followed.
*
* data_size: (read/write)
* The user application should read data_size to get the size in bytes of
* the data copied in the migration region during the _SAVING state and
* write the size in bytes of the data copied in the migration region
* during the _RESUMING state.
*
* The format of the migration region is as follows:
* ------------------------------------------------------------------
* |vfio_device_migration_info| data section |
* | | /// |
* ------------------------------------------------------------------
* ^ ^
* offset 0-trapped part data_offset
*
* The structure vfio_device_migration_info is always followed by the data
* section in the region, so data_offset will always be nonzero. The offset
* from where the data is copied is decided by the kernel driver. The data
* section can be trapped, mmapped, or partitioned, depending on how the kernel
* driver defines the data section. The data section partition can be defined
* as mapped by the sparse mmap capability. If mmapped, data_offset must be
* page aligned, whereas initial section which contains the
* vfio_device_migration_info structure, might not end at the offset, which is
* page aligned. The user is not required to access through mmap regardless
* of the capabilities of the region mmap.
* The vendor driver should determine whether and how to partition the data
* section. The vendor driver should return data_offset accordingly.
*
* The sequence to be followed while in pre-copy state and stop-and-copy state
* is as follows:
* a. Read pending_bytes, indicating the start of a new iteration to get device
* data. Repeated read on pending_bytes at this stage should have no side
* effects.
* If pending_bytes == 0, the user application should not iterate to get data
* for that device.
* If pending_bytes > 0, perform the following steps.
* b. Read data_offset, indicating that the vendor driver should make data
* available through the data section. The vendor driver should return this
* read operation only after data is available from (region + data_offset)
* to (region + data_offset + data_size).
* c. Read data_size, which is the amount of data in bytes available through
* the migration region.
* Read on data_offset and data_size should return the offset and size of
* the current buffer if the user application reads data_offset and
* data_size more than once here.
* d. Read data_size bytes of data from (region + data_offset) from the
* migration region.
* e. Process the data.
* f. Read pending_bytes, which indicates that the data from the previous
* iteration has been read. If pending_bytes > 0, go to step b.
*
* The user application can transition from the _SAVING|_RUNNING
* (pre-copy state) to the _SAVING (stop-and-copy) state regardless of the
* number of pending bytes. The user application should iterate in _SAVING
* (stop-and-copy) until pending_bytes is 0.
*
* The sequence to be followed while _RESUMING device state is as follows:
* While data for this device is available, repeat the following steps:
* a. Read data_offset from where the user application should write data.
* b. Write migration data starting at the migration region + data_offset for
* the length determined by data_size from the migration source.
* c. Write data_size, which indicates to the vendor driver that data is
* written in the migration region. Vendor driver must return this write
* operations on consuming data. Vendor driver should apply the
* user-provided migration region data to the device resume state.
*
* If an error occurs during the above sequences, the vendor driver can return
* an error code for next read() or write() operation, which will terminate the
* loop. The user application should then take the next necessary action, for
* example, failing migration or terminating the user application.
*
* For the user application, data is opaque. The user application should write
* data in the same order as the data is received and the data should be of
* same transaction size at the source.
*/
struct vfio_device_migration_info {
__u32 device_state; /* VFIO device state */
#define VFIO_DEVICE_STATE_STOP (0)
#define VFIO_DEVICE_STATE_RUNNING (1 << 0)
#define VFIO_DEVICE_STATE_SAVING (1 << 1)
#define VFIO_DEVICE_STATE_RESUMING (1 << 2)
#define VFIO_DEVICE_STATE_MASK (VFIO_DEVICE_STATE_RUNNING |
VFIO_DEVICE_STATE_SAVING |
VFIO_DEVICE_STATE_RESUMING)
#define VFIO_DEVICE_STATE_VALID(state)
(state & VFIO_DEVICE_STATE_RESUMING ?
(state & VFIO_DEVICE_STATE_MASK) == VFIO_DEVICE_STATE_RESUMING : 1)
#define VFIO_DEVICE_STATE_IS_ERROR(state)
((state & VFIO_DEVICE_STATE_MASK) == (VFIO_DEVICE_STATE_SAVING |
VFIO_DEVICE_STATE_RESUMING))
#define VFIO_DEVICE_STATE_SET_ERROR(state)
((state & ~VFIO_DEVICE_STATE_MASK) | VFIO_DEVICE_SATE_SAVING |
VFIO_DEVICE_STATE_RESUMING)
__u32 reserved;
__u64 pending_bytes;
__u64 data_offset;
__u64 data_size;
};
/*
* The MSIX mappable capability informs that MSIX data of a BAR can be mmapped
* which allows direct access to non-MSIX registers which happened to be within
* the same system page.
*
* Even though the userspace gets direct access to the MSIX data, the existing
* VFIO_DEVICE_SET_IRQS interface must still be used for MSIX configuration.
*/
#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3
/*
* Capability with compressed real address (aka SSA - small system address)
* where GPU RAM is mapped on a system bus. Used by a GPU for DMA routing
* and by the userspace to associate a NVLink bridge with a GPU.
*/
#define VFIO_REGION_INFO_CAP_NVLINK2_SSATGT 4
struct vfio_region_info_cap_nvlink2_ssatgt {
struct vfio_info_cap_header header;
__u64 tgt;
};
/*
* Capability with an NVLink link speed. The value is read by
* the NVlink2 bridge driver from the bridge's "ibm,nvlink-speed"
* property in the device tree. The value is fixed in the hardware
* and failing to provide the correct value results in the link
* not working with no indication from the driver why.
*/
#define VFIO_REGION_INFO_CAP_NVLINK2_LNKSPD 5
struct vfio_region_info_cap_nvlink2_lnkspd {
struct vfio_info_cap_header header;
__u32 link_speed;
__u32 __pad;
};
/**
* VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
* struct vfio_irq_info)
*
* Retrieve information about a device IRQ. Caller provides
* struct vfio_irq_info with index value set. Caller sets argsz.
* Implementation of IRQ mapping is bus driver specific. Indexes
* using multiple IRQs are primarily intended to support MSI-like
* interrupt blocks. Zero count irq blocks may be used to describe
* unimplemented interrupt types.
*
* The EVENTFD flag indicates the interrupt index supports eventfd based
* signaling.
*
* The MASKABLE flags indicates the index supports MASK and UNMASK
* actions described below.
*
* AUTOMASKED indicates that after signaling, the interrupt line is
* automatically masked by VFIO and the user needs to unmask the line
* to receive new interrupts. This is primarily intended to distinguish
* level triggered interrupts.
*
* The NORESIZE flag indicates that the interrupt lines within the index
* are setup as a set and new subindexes cannot be enabled without first
* disabling the entire index. This is used for interrupts like PCI MSI
* and MSI-X where the driver may only use a subset of the available
* indexes, but VFIO needs to enable a specific number of vectors
* upfront. In the case of MSI-X, where the user can enable MSI-X and
* then add and unmask vectors, it's up to userspace to make the decision
* whether to allocate the maximum supported number of vectors or tear
* down setup and incrementally increase the vectors as each is enabled.
*/
struct vfio_irq_info {
__u32 argsz;
__u32 flags;
#define VFIO_IRQ_INFO_EVENTFD (1 << 0)
#define VFIO_IRQ_INFO_MASKABLE (1 << 1)
#define VFIO_IRQ_INFO_AUTOMASKED (1 << 2)
#define VFIO_IRQ_INFO_NORESIZE (1 << 3)
__u32 index; /* IRQ index */
__u32 count; /* Number of IRQs within this index */
};
#define VFIO_DEVICE_GET_IRQ_INFO _IO(VFIO_TYPE, VFIO_BASE + 9)
/**
* VFIO_DEVICE_SET_IRQS - _IOW(VFIO_TYPE, VFIO_BASE + 10, struct vfio_irq_set)
*
* Set signaling, masking, and unmasking of interrupts. Caller provides
* struct vfio_irq_set with all fields set. 'start' and 'count' indicate
* the range of subindexes being specified.
*
* The DATA flags specify the type of data provided. If DATA_NONE, the
* operation performs the specified action immediately on the specified
* interrupt(s). For example, to unmask AUTOMASKED interrupt [0,0]:
* flags = (DATA_NONE|ACTION_UNMASK), index = 0, start = 0, count = 1.
*
* DATA_BOOL allows sparse support for the same on arrays of interrupts.
* For example, to mask interrupts [0,1] and [0,3] (but not [0,2]):
* flags = (DATA_BOOL|ACTION_MASK), index = 0, start = 1, count = 3,
* data = {1,0,1}
*
* DATA_EVENTFD binds the specified ACTION to the provided __s32 eventfd.
* A value of -1 can be used to either de-assign interrupts if already
* assigned or skip un-assigned interrupts. For example, to set an eventfd
* to be trigger for interrupts [0,0] and [0,2]:
* flags = (DATA_EVENTFD|ACTION_TRIGGER), index = 0, start = 0, count = 3,
* data = {fd1, -1, fd2}
* If index [0,1] is previously set, two count = 1 ioctls calls would be
* required to set [0,0] and [0,2] without changing [0,1].
*
* Once a signaling mechanism is set, DATA_BOOL or DATA_NONE can be used
* with ACTION_TRIGGER to perform kernel level interrupt loopback testing
* from userspace (ie. simulate hardware triggering).
*
* Setting of an event triggering mechanism to userspace for ACTION_TRIGGER
* enables the interrupt index for the device. Individual subindex interrupts
* can be disabled using the -1 value for DATA_EVENTFD or the index can be
* disabled as a whole with: flags = (DATA_NONE|ACTION_TRIGGER), count = 0.
*
* Note that ACTION_[UN]MASK specify user->kernel signaling (irqfds) while
* ACTION_TRIGGER specifies kernel->user signaling.
*/
struct vfio_irq_set {
__u32 argsz;
__u32 flags;
#define VFIO_IRQ_SET_DATA_NONE (1 << 0) /* Data not present */
#define VFIO_IRQ_SET_DATA_BOOL (1 << 1) /* Data is bool (u8) */
#define VFIO_IRQ_SET_DATA_EVENTFD (1 << 2) /* Data is eventfd (s32) */
#define VFIO_IRQ_SET_ACTION_MASK (1 << 3) /* Mask interrupt */
#define VFIO_IRQ_SET_ACTION_UNMASK (1 << 4) /* Unmask interrupt */
#define VFIO_IRQ_SET_ACTION_TRIGGER (1 << 5) /* Trigger interrupt */
__u32 index;
__u32 start;
__u32 count;
__u8 data[];
};
#define VFIO_DEVICE_SET_IRQS _IO(VFIO_TYPE, VFIO_BASE + 10)
#define VFIO_IRQ_SET_DATA_TYPE_MASK (VFIO_IRQ_SET_DATA_NONE |
VFIO_IRQ_SET_DATA_BOOL |
VFIO_IRQ_SET_DATA_EVENTFD)
#define VFIO_IRQ_SET_ACTION_TYPE_MASK (VFIO_IRQ_SET_ACTION_MASK |
VFIO_IRQ_SET_ACTION_UNMASK |
VFIO_IRQ_SET_ACTION_TRIGGER)
/**
* VFIO_DEVICE_RESET - _IO(VFIO_TYPE, VFIO_BASE + 11)
*
* Reset a device.
*/
#define VFIO_DEVICE_RESET _IO(VFIO_TYPE, VFIO_BASE + 11)
/*
* The VFIO-PCI bus driver makes use of the following fixed region and
* IRQ index mapping. Unimplemented regions return a size of zero.
* Unimplemented IRQ types return a count of zero.
*/
enum {
VFIO_PCI_BAR0_REGION_INDEX,
VFIO_PCI_BAR1_REGION_INDEX,
VFIO_PCI_BAR2_REGION_INDEX,
VFIO_PCI_BAR3_REGION_INDEX,
VFIO_PCI_BAR4_REGION_INDEX,
VFIO_PCI_BAR5_REGION_INDEX,
VFIO_PCI_ROM_REGION_INDEX,
VFIO_PCI_CONFIG_REGION_INDEX,
/*
* Expose VGA regions defined for PCI base class 03, subclass 00.
* This includes I/O port ranges 0x3b0 to 0x3bb and 0x3c0 to 0x3df
* as well as the MMIO range 0xa0000 to 0xbffff. Each implemented
* range is found at it's identity mapped offset from the region
* offset, for example 0x3b0 is region_info.offset + 0x3b0. Areas
* between described ranges are unimplemented.
*/
VFIO_PCI_VGA_REGION_INDEX,
VFIO_PCI_NUM_REGIONS = 9 /* Fixed user ABI, region indexes >=9 use */
/* device specific cap to define content. */
};
enum {
VFIO_PCI_INTX_IRQ_INDEX,
VFIO_PCI_MSI_IRQ_INDEX,
VFIO_PCI_MSIX_IRQ_INDEX,
VFIO_PCI_ERR_IRQ_INDEX,
VFIO_PCI_REQ_IRQ_INDEX,
VFIO_PCI_NUM_IRQS
};
/*
* The vfio-ccw bus driver makes use of the following fixed region and
* IRQ index mapping. Unimplemented regions return a size of zero.
* Unimplemented IRQ types return a count of zero.
*/
enum {
VFIO_CCW_CONFIG_REGION_INDEX,
VFIO_CCW_NUM_REGIONS
};
enum {
VFIO_CCW_IO_IRQ_INDEX,
VFIO_CCW_CRW_IRQ_INDEX,
VFIO_CCW_NUM_IRQS
};
/**
* VFIO_DEVICE_GET_PCI_HOT_RESET_INFO - _IORW(VFIO_TYPE, VFIO_BASE + 12,
* struct vfio_pci_hot_reset_info)
*
* Return: 0 on success, -errno on failure:
* -enospc = insufficient buffer, -enodev = unsupported for device.
*/
struct vfio_pci_dependent_device {
__u32 group_id;
__u16 segment;
__u8 bus;
__u8 devfn; /* Use PCI_SLOT/PCI_FUNC */
};
struct vfio_pci_hot_reset_info {
__u32 argsz;
__u32 flags;
__u32 count;
struct vfio_pci_dependent_device devices[];
};
#define VFIO_DEVICE_GET_PCI_HOT_RESET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
/**
* VFIO_DEVICE_PCI_HOT_RESET - _IOW(VFIO_TYPE, VFIO_BASE + 13,
* struct vfio_pci_hot_reset)
*
* Return: 0 on success, -errno on failure.
*/
struct vfio_pci_hot_reset {
__u32 argsz;
__u32 flags;
__u32 count;
__s32 group_fds[];
};
#define VFIO_DEVICE_PCI_HOT_RESET _IO(VFIO_TYPE, VFIO_BASE + 13)
/**
* VFIO_DEVICE_QUERY_GFX_PLANE - _IOW(VFIO_TYPE, VFIO_BASE + 14,
* struct vfio_device_query_gfx_plane)
*
* Set the drm_plane_type and flags, then retrieve the gfx plane info.
*
* flags supported:
* - VFIO_GFX_PLANE_TYPE_PROBE and VFIO_GFX_PLANE_TYPE_DMABUF are set
* to ask if the mdev supports dma-buf. 0 on support, -EINVAL on no
* support for dma-buf.
* - VFIO_GFX_PLANE_TYPE_PROBE and VFIO_GFX_PLANE_TYPE_REGION are set
* to ask if the mdev supports region. 0 on support, -EINVAL on no
* support for region.
* - VFIO_GFX_PLANE_TYPE_DMABUF or VFIO_GFX_PLANE_TYPE_REGION is set
* with each call to query the plane info.
* - Others are invalid and return -EINVAL.
*
* Note:
* 1. Plane could be disabled by guest. In that case, success will be
* returned with zero-initialized drm_format, size, width and height
* fields.
* 2. x_hot/y_hot is set to 0xFFFFFFFF if no hotspot information available
*
* Return: 0 on success, -errno on other failure.
*/
struct vfio_device_gfx_plane_info {
__u32 argsz;
__u32 flags;
#define VFIO_GFX_PLANE_TYPE_PROBE (1 << 0)
#define VFIO_GFX_PLANE_TYPE_DMABUF (1 << 1)
#define VFIO_GFX_PLANE_TYPE_REGION (1 << 2)
/* in */
__u32 drm_plane_type; /* type of plane: DRM_PLANE_TYPE_* */
/* out */
__u32 drm_format; /* drm format of plane */
__u64 drm_format_mod; /* tiled mode */
__u32 width; /* width of plane */
__u32 height; /* height of plane */
__u32 stride; /* stride of plane */
__u32 size; /* size of plane in bytes, align on page*/
__u32 x_pos; /* horizontal position of cursor plane */
__u32 y_pos; /* vertical position of cursor plane*/
__u32 x_hot; /* horizontal position of cursor hotspot */
__u32 y_hot; /* vertical position of cursor hotspot */
union {
__u32 region_index; /* region index */
__u32 dmabuf_id; /* dma-buf id */
};
};
#define VFIO_DEVICE_QUERY_GFX_PLANE _IO(VFIO_TYPE, VFIO_BASE + 14)
/**
* VFIO_DEVICE_GET_GFX_DMABUF - _IOW(VFIO_TYPE, VFIO_BASE + 15, __u32)
*
* Return a new dma-buf file descriptor for an exposed guest framebuffer
* described by the provided dmabuf_id. The dmabuf_id is returned from VFIO_
* DEVICE_QUERY_GFX_PLANE as a token of the exposed guest framebuffer.
*/
#define VFIO_DEVICE_GET_GFX_DMABUF _IO(VFIO_TYPE, VFIO_BASE + 15)
/**
* VFIO_DEVICE_IOEVENTFD - _IOW(VFIO_TYPE, VFIO_BASE + 16,
* struct vfio_device_ioeventfd)
*
* Perform a write to the device at the specified device fd offset, with
* the specified data and width when the provided eventfd is triggered.
* vfio bus drivers may not support this for all regions, for all widths,
* or at all. vfio-pci currently only enables support for BAR regions,
* excluding the MSI-X vector table.
*
* Return: 0 on success, -errno on failure.
*/
struct vfio_device_ioeventfd {
__u32 argsz;
__u32 flags;
#define VFIO_DEVICE_IOEVENTFD_8 (1 << 0) /* 1-byte write */
#define VFIO_DEVICE_IOEVENTFD_16 (1 << 1) /* 2-byte write */
#define VFIO_DEVICE_IOEVENTFD_32 (1 << 2) /* 4-byte write */
#define VFIO_DEVICE_IOEVENTFD_64 (1 << 3) /* 8-byte write */
#define VFIO_DEVICE_IOEVENTFD_SIZE_MASK (0xf)
__u64 offset; /* device fd offset of write */
__u64 data; /* data to be written */
__s32 fd; /* -1 for de-assignment */
};
#define VFIO_DEVICE_IOEVENTFD _IO(VFIO_TYPE, VFIO_BASE + 16)
/**
* VFIO_DEVICE_FEATURE - _IORW(VFIO_TYPE, VFIO_BASE + 17,
* struct vfio_device_feature)
*
* Get, set, or probe feature data of the device. The feature is selected
* using the FEATURE_MASK portion of the flags field. Support for a feature
* can be probed by setting both the FEATURE_MASK and PROBE bits. A probe
* may optionally include the GET and/or SET bits to determine read vs write
* access of the feature respectively. Probing a feature will return success
* if the feature is supported and all of the optionally indicated GET/SET
* methods are supported. The format of the data portion of the structure is
* specific to the given feature. The data portion is not required for
* probing. GET and SET are mutually exclusive, except for use with PROBE.
*
* Return 0 on success, -errno on failure.
*/
struct vfio_device_feature {
__u32 argsz;
__u32 flags;
#define VFIO_DEVICE_FEATURE_MASK (0xffff) /* 16-bit feature index */
#define VFIO_DEVICE_FEATURE_GET (1 << 16) /* Get feature into data[] */
#define VFIO_DEVICE_FEATURE_SET (1 << 17) /* Set feature from data[] */
#define VFIO_DEVICE_FEATURE_PROBE (1 << 18) /* Probe feature support */
__u8 data[];
};
#define VFIO_DEVICE_FEATURE _IO(VFIO_TYPE, VFIO_BASE + 17)
/*
* Provide support for setting a PCI VF Token, which is used as a shared
* secret between PF and VF drivers. This feature may only be set on a
* PCI SR-IOV PF when SR-IOV is enabled on the PF and there are no existing
* open VFs. Data provided when setting this feature is a 16-byte array
* (__u8 b[16]), representing a UUID.
*/
#define VFIO_DEVICE_FEATURE_PCI_VF_TOKEN (0)
/* -------- API for Type1 VFIO IOMMU -------- */
/**
* VFIO_IOMMU_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 12, struct vfio_iommu_info)
*
* Retrieve information about the IOMMU object. Fills in provided
* struct vfio_iommu_info. Caller sets argsz.
*
* XXX Should we do these by CHECK_EXTENSION too?
*/
struct vfio_iommu_type1_info {
__u32 argsz;
__u32 flags;
#define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page sizes info */
#define VFIO_IOMMU_INFO_CAPS (1 << 1) /* Info supports caps */
__u64 iova_pgsizes; /* Bitmap of supported page sizes */
__u32 cap_offset; /* Offset within info struct of first cap */
};
/*
* The IOVA capability allows to report the valid IOVA range(s)
* excluding any non-relaxable reserved regions exposed by
* devices attached to the container. Any DMA map attempt
* outside the valid iova range will return error.
*
* The structures below define version 1 of this capability.
*/
#define VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE 1
struct vfio_iova_range {
__u64 start;
__u64 end;
};
struct vfio_iommu_type1_info_cap_iova_range {
struct vfio_info_cap_header header;
__u32 nr_iovas;
__u32 reserved;
struct vfio_iova_range iova_ranges[];
};
/*
* The migration capability allows to report supported features for migration.
*
* The structures below define version 1 of this capability.
*
* The existence of this capability indicates that IOMMU kernel driver supports
* dirty page logging.
*
* pgsize_bitmap: Kernel driver returns bitmap of supported page sizes for dirty
* page logging.
* max_dirty_bitmap_size: Kernel driver returns maximum supported dirty bitmap
* size in bytes that can be used by user applications when getting the dirty
* bitmap.
*/
#define VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION 2
struct vfio_iommu_type1_info_cap_migration {
struct vfio_info_cap_header header;
__u32 flags;
__u64 pgsize_bitmap;
__u64 max_dirty_bitmap_size; /* in bytes */
};
/*
* The DMA available capability allows to report the current number of
* simultaneously outstanding DMA mappings that are allowed.
*
* The structure below defines version 1 of this capability.
*
* avail: specifies the current number of outstanding DMA mappings allowed.
*/
#define VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL 3
struct vfio_iommu_type1_info_dma_avail {
struct vfio_info_cap_header header;
__u32 avail;
};
#define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
/**
* VFIO_IOMMU_MAP_DMA - _IOW(VFIO_TYPE, VFIO_BASE + 13, struct vfio_dma_map)
*
* Map process virtual addresses to IO virtual addresses using the
* provided struct vfio_dma_map. Caller sets argsz. READ &/ WRITE required.
*/
struct vfio_iommu_type1_dma_map {
__u32 argsz;
__u32 flags;
#define VFIO_DMA_MAP_FLAG_READ (1 << 0) /* readable from device */
#define VFIO_DMA_MAP_FLAG_WRITE (1 << 1) /* writable from device */
__u64 vaddr; /* Process virtual address */
__u64 iova; /* IO virtual address */
__u64 size; /* Size of mapping (bytes) */
};
#define VFIO_IOMMU_MAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 13)
struct vfio_bitmap {
__u64 pgsize; /* page size for bitmap in bytes */
__u64 size; /* in bytes */
__u64 __user *data; /* one bit per page */
};
/**
* VFIO_IOMMU_UNMAP_DMA - _IOWR(VFIO_TYPE, VFIO_BASE + 14,
* struct vfio_dma_unmap)
*
* Unmap IO virtual addresses using the provided struct vfio_dma_unmap.
* Caller sets argsz. The actual unmapped size is returned in the size
* field. No guarantee is made to the user that arbitrary unmaps of iova
* or size different from those used in the original mapping call will
* succeed.
* VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get the dirty bitmap
* before unmapping IO virtual addresses. When this flag is set, the user must
* provide a struct vfio_bitmap in data[]. User must provide zero-allocated
* memory via vfio_bitmap.data and its size in the vfio_bitmap.size field.
* A bit in the bitmap represents one page, of user provided page size in
* vfio_bitmap.pgsize field, consecutively starting from iova offset. Bit set
* indicates that the page at that offset from iova is dirty. A Bitmap of the
* pages in the range of unmapped size is returned in the user-provided
* vfio_bitmap.data.
*/
struct vfio_iommu_type1_dma_unmap {
__u32 argsz;
__u32 flags;
#define VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP (1 << 0)
__u64 iova; /* IO virtual address */
__u64 size; /* Size of mapping (bytes) */
__u8 data[];
};
#define VFIO_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14)
/*
* IOCTLs to enable/disable IOMMU container usage.
* No parameters are supported.
*/
#define VFIO_IOMMU_ENABLE _IO(VFIO_TYPE, VFIO_BASE + 15)
#define VFIO_IOMMU_DISABLE _IO(VFIO_TYPE, VFIO_BASE + 16)
/**
* VFIO_IOMMU_DIRTY_PAGES - _IOWR(VFIO_TYPE, VFIO_BASE + 17,
* struct vfio_iommu_type1_dirty_bitmap)
* IOCTL is used for dirty pages logging.
* Caller should set flag depending on which operation to perform, details as
* below:
*
* Calling the IOCTL with VFIO_IOMMU_DIRTY_PAGES_FLAG_START flag set, instructs
* the IOMMU driver to log pages that are dirtied or potentially dirtied by
* the device; designed to be used when a migration is in progress. Dirty pages
* are logged until logging is disabled by user application by calling the IOCTL
* with VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP flag.
*
* Calling the IOCTL with VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP flag set, instructs
* the IOMMU driver to stop logging dirtied pages.
*
* Calling the IOCTL with VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP flag set
* returns the dirty pages bitmap for IOMMU container for a given IOVA range.
* The user must specify the IOVA range and the pgsize through the structure
* vfio_iommu_type1_dirty_bitmap_get in the data[] portion. This interface
* supports getting a bitmap of the smallest supported pgsize only and can be
* modified in future to get a bitmap of any specified supported pgsize. The
* user must provide a zeroed memory area for the bitmap memory and specify its
* size in bitmap.size. One bit is used to represent one page consecutively
* starting from iova offset. The user should provide page size in bitmap.pgsize
* field. A bit set in the bitmap indicates that the page at that offset from
* iova is dirty. The caller must set argsz to a value including the size of
* structure vfio_iommu_type1_dirty_bitmap_get, but excluding the size of the
* actual bitmap. If dirty pages logging is not enabled, an error will be
* returned.
*
* Only one of the flags _START, _STOP and _GET may be specified at a time.
*
*/
struct vfio_iommu_type1_dirty_bitmap {
__u32 argsz;
__u32 flags;
#define VFIO_IOMMU_DIRTY_PAGES_FLAG_START (1 << 0)
#define VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP (1 << 1)
#define VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP (1 << 2)
__u8 data[];
};
struct vfio_iommu_type1_dirty_bitmap_get {
__u64 iova; /* IO virtual address */
__u64 size; /* Size of iova range */
struct vfio_bitmap bitmap;
};
#define VFIO_IOMMU_DIRTY_PAGES _IO(VFIO_TYPE, VFIO_BASE + 17)
/* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */
/*
* The SPAPR TCE DDW info struct provides the information about
* the details of Dynamic DMA window capability.
*
* @pgsizes contains a page size bitmask, 4K/64K/16M are supported.
* @max_dynamic_windows_supported tells the maximum number of windows
* which the platform can create.
* @levels tells the maximum number of levels in multi-level IOMMU tables;
* this allows splitting a table into smaller chunks which reduces
* the amount of physically contiguous memory required for the table.
*/
struct vfio_iommu_spapr_tce_ddw_info {
__u64 pgsizes; /* Bitmap of supported page sizes */
__u32 max_dynamic_windows_supported;
__u32 levels;
};
/*
* The SPAPR TCE info struct provides the information about the PCI bus
* address ranges available for DMA, these values are programmed into
* the hardware so the guest has to know that information.
*
* The DMA 32 bit window start is an absolute PCI bus address.
* The IOVA address passed via map/unmap ioctls are absolute PCI bus
* addresses too so the window works as a filter rather than an offset
* for IOVA addresses.
*
* Flags supported:
* - VFIO_IOMMU_SPAPR_INFO_DDW: informs the userspace that dynamic DMA windows
* (DDW) support is present. @ddw is only supported when DDW is present.
*/
struct vfio_iommu_spapr_tce_info {
__u32 argsz;
__u32 flags;
#define VFIO_IOMMU_SPAPR_INFO_DDW (1 << 0) /* DDW supported */
__u32 dma32_window_start; /* 32 bit window start (bytes) */
__u32 dma32_window_size; /* 32 bit window size (bytes) */
struct vfio_iommu_spapr_tce_ddw_info ddw;
};
#define VFIO_IOMMU_SPAPR_TCE_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
/*
* EEH PE operation struct provides ways to:
* - enable/disable EEH functionality;
* - unfreeze IO/DMA for frozen PE;
* - read PE state;
* - reset PE;
* - configure PE;
* - inject EEH error.
*/
struct vfio_eeh_pe_err {
__u32 type;
__u32 func;
__u64 addr;
__u64 mask;
};
struct vfio_eeh_pe_op {
__u32 argsz;
__u32 flags;
__u32 op;
union {
struct vfio_eeh_pe_err err;
};
};
#define VFIO_EEH_PE_DISABLE 0 /* Disable EEH functionality */
#define VFIO_EEH_PE_ENABLE 1 /* Enable EEH functionality */
#define VFIO_EEH_PE_UNFREEZE_IO 2 /* Enable IO for frozen PE */
#define VFIO_EEH_PE_UNFREEZE_DMA 3 /* Enable DMA for frozen PE */
#define VFIO_EEH_PE_GET_STATE 4 /* PE state retrieval */
#define VFIO_EEH_PE_STATE_NORMAL 0 /* PE in functional state */
#define VFIO_EEH_PE_STATE_RESET 1 /* PE reset in progress */
#define VFIO_EEH_PE_STATE_STOPPED 2 /* Stopped DMA and IO */
#define VFIO_EEH_PE_STATE_STOPPED_DMA 4 /* Stopped DMA only */
#define VFIO_EEH_PE_STATE_UNAVAIL 5 /* State unavailable */
#define VFIO_EEH_PE_RESET_DEACTIVATE 5 /* Deassert PE reset */
#define VFIO_EEH_PE_RESET_HOT 6 /* Assert hot reset */
#define VFIO_EEH_PE_RESET_FUNDAMENTAL 7 /* Assert fundamental reset */
#define VFIO_EEH_PE_CONFIGURE 8 /* PE configuration */
#define VFIO_EEH_PE_INJECT_ERR 9 /* Inject EEH error */
#define VFIO_EEH_PE_OP _IO(VFIO_TYPE, VFIO_BASE + 21)
/**
* VFIO_IOMMU_SPAPR_REGISTER_MEMORY - _IOW(VFIO_TYPE, VFIO_BASE + 17, struct vfio_iommu_spapr_register_memory)
*
* Registers user space memory where DMA is allowed. It pins
* user pages and does the locked memory accounting so
* subsequent VFIO_IOMMU_MAP_DMA/VFIO_IOMMU_UNMAP_DMA calls
* get faster.
*/
struct vfio_iommu_spapr_register_memory {
__u32 argsz;
__u32 flags;
__u64 vaddr; /* Process virtual address */
__u64 size; /* Size of mapping (bytes) */
};
#define VFIO_IOMMU_SPAPR_REGISTER_MEMORY _IO(VFIO_TYPE, VFIO_BASE + 17)
/**
* VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY - _IOW(VFIO_TYPE, VFIO_BASE + 18, struct vfio_iommu_spapr_register_memory)
*
* Unregisters user space memory registered with
* VFIO_IOMMU_SPAPR_REGISTER_MEMORY.
* Uses vfio_iommu_spapr_register_memory for parameters.
*/
#define VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY _IO(VFIO_TYPE, VFIO_BASE + 18)
/**
* VFIO_IOMMU_SPAPR_TCE_CREATE - _IOWR(VFIO_TYPE, VFIO_BASE + 19, struct vfio_iommu_spapr_tce_create)
*
* Creates an additional TCE table and programs it (sets a new DMA window)
* to every IOMMU group in the container. It receives page shift, window
* size and number of levels in the TCE table being created.
*
* It allocates and returns an offset on a PCI bus of the new DMA window.
*/
struct vfio_iommu_spapr_tce_create {
__u32 argsz;
__u32 flags;
/* in */
__u32 page_shift;
__u32 __resv1;
__u64 window_size;
__u32 levels;
__u32 __resv2;
/* out */
__u64 start_addr;
};
#define VFIO_IOMMU_SPAPR_TCE_CREATE _IO(VFIO_TYPE, VFIO_BASE + 19)
/**
* VFIO_IOMMU_SPAPR_TCE_REMOVE - _IOW(VFIO_TYPE, VFIO_BASE + 20, struct vfio_iommu_spapr_tce_remove)
*
* Unprograms a TCE table from all groups in the container and destroys it.
* It receives a PCI bus offset as a window id.
*/
struct vfio_iommu_spapr_tce_remove {
__u32 argsz;
__u32 flags;
/* in */
__u64 start_addr;
};
#define VFIO_IOMMU_SPAPR_TCE_REMOVE _IO(VFIO_TYPE, VFIO_BASE + 20)
/* ***************************************************************** */
#endif /* _UAPIVFIO_H */
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