From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ... --- drivers/vfio/group.c | 877 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 877 insertions(+) create mode 100644 drivers/vfio/group.c (limited to 'drivers/vfio/group.c') diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c new file mode 100644 index 000000000..bb24b2f02 --- /dev/null +++ b/drivers/vfio/group.c @@ -0,0 +1,877 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * VFIO core + * + * Copyright (C) 2012 Red Hat, Inc. All rights reserved. + * Author: Alex Williamson + * + * Derived from original vfio: + * Copyright 2010 Cisco Systems, Inc. All rights reserved. + * Author: Tom Lyon, pugs@cisco.com + */ + +#include +#include +#include +#include "vfio.h" + +static struct vfio { + struct class *class; + struct list_head group_list; + struct mutex group_lock; /* locks group_list */ + struct ida group_ida; + dev_t group_devt; +} vfio; + +static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, + char *buf) +{ + struct vfio_device *it, *device = ERR_PTR(-ENODEV); + + mutex_lock(&group->device_lock); + list_for_each_entry(it, &group->device_list, group_next) { + int ret; + + if (it->ops->match) { + ret = it->ops->match(it, buf); + if (ret < 0) { + device = ERR_PTR(ret); + break; + } + } else { + ret = !strcmp(dev_name(it->dev), buf); + } + + if (ret && vfio_device_try_get_registration(it)) { + device = it; + break; + } + } + mutex_unlock(&group->device_lock); + + return device; +} + +/* + * VFIO Group fd, /dev/vfio/$GROUP + */ +static bool vfio_group_has_iommu(struct vfio_group *group) +{ + lockdep_assert_held(&group->group_lock); + /* + * There can only be users if there is a container, and if there is a + * container there must be users. + */ + WARN_ON(!group->container != !group->container_users); + + return group->container || group->iommufd; +} + +/* + * VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or + * if there was no container to unset. Since the ioctl is called on + * the group, we know that still exists, therefore the only valid + * transition here is 1->0. + */ +static int vfio_group_ioctl_unset_container(struct vfio_group *group) +{ + int ret = 0; + + mutex_lock(&group->group_lock); + if (!vfio_group_has_iommu(group)) { + ret = -EINVAL; + goto out_unlock; + } + if (group->container) { + if (group->container_users != 1) { + ret = -EBUSY; + goto out_unlock; + } + vfio_group_detach_container(group); + } + if (group->iommufd) { + iommufd_ctx_put(group->iommufd); + group->iommufd = NULL; + } + +out_unlock: + mutex_unlock(&group->group_lock); + return ret; +} + +static int vfio_group_ioctl_set_container(struct vfio_group *group, + int __user *arg) +{ + struct vfio_container *container; + struct iommufd_ctx *iommufd; + struct fd f; + int ret; + int fd; + + if (get_user(fd, arg)) + return -EFAULT; + + f = fdget(fd); + if (!f.file) + return -EBADF; + + mutex_lock(&group->group_lock); + if (vfio_group_has_iommu(group)) { + ret = -EINVAL; + goto out_unlock; + } + if (!group->iommu_group) { + ret = -ENODEV; + goto out_unlock; + } + + container = vfio_container_from_file(f.file); + if (container) { + ret = vfio_container_attach_group(container, group); + goto out_unlock; + } + + iommufd = iommufd_ctx_from_file(f.file); + if (!IS_ERR(iommufd)) { + u32 ioas_id; + + ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id); + if (ret) { + iommufd_ctx_put(group->iommufd); + goto out_unlock; + } + + group->iommufd = iommufd; + goto out_unlock; + } + + /* The FD passed is not recognized. */ + ret = -EBADFD; + +out_unlock: + mutex_unlock(&group->group_lock); + fdput(f); + return ret; +} + +static int vfio_device_group_open(struct vfio_device *device) +{ + int ret; + + mutex_lock(&device->group->group_lock); + if (!vfio_group_has_iommu(device->group)) { + ret = -EINVAL; + goto out_unlock; + } + + /* + * Here we pass the KVM pointer with the group under the lock. If the + * device driver will use it, it must obtain a reference and release it + * during close_device. + */ + ret = vfio_device_open(device, device->group->iommufd, + device->group->kvm); + +out_unlock: + mutex_unlock(&device->group->group_lock); + return ret; +} + +void vfio_device_group_close(struct vfio_device *device) +{ + mutex_lock(&device->group->group_lock); + vfio_device_close(device, device->group->iommufd); + mutex_unlock(&device->group->group_lock); +} + +static struct file *vfio_device_open_file(struct vfio_device *device) +{ + struct file *filep; + int ret; + + ret = vfio_device_group_open(device); + if (ret) + goto err_out; + + /* + * We can't use anon_inode_getfd() because we need to modify + * the f_mode flags directly to allow more than just ioctls + */ + filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops, + device, O_RDWR); + if (IS_ERR(filep)) { + ret = PTR_ERR(filep); + goto err_close_device; + } + + /* + * TODO: add an anon_inode interface to do this. + * Appears to be missing by lack of need rather than + * explicitly prevented. Now there's need. + */ + filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE); + + if (device->group->type == VFIO_NO_IOMMU) + dev_warn(device->dev, "vfio-noiommu device opened by user " + "(%s:%d)\n", current->comm, task_pid_nr(current)); + /* + * On success the ref of device is moved to the file and + * put in vfio_device_fops_release() + */ + return filep; + +err_close_device: + vfio_device_group_close(device); +err_out: + return ERR_PTR(ret); +} + +static int vfio_group_ioctl_get_device_fd(struct vfio_group *group, + char __user *arg) +{ + struct vfio_device *device; + struct file *filep; + char *buf; + int fdno; + int ret; + + buf = strndup_user(arg, PAGE_SIZE); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + device = vfio_device_get_from_name(group, buf); + kfree(buf); + if (IS_ERR(device)) + return PTR_ERR(device); + + fdno = get_unused_fd_flags(O_CLOEXEC); + if (fdno < 0) { + ret = fdno; + goto err_put_device; + } + + filep = vfio_device_open_file(device); + if (IS_ERR(filep)) { + ret = PTR_ERR(filep); + goto err_put_fdno; + } + + fd_install(fdno, filep); + return fdno; + +err_put_fdno: + put_unused_fd(fdno); +err_put_device: + vfio_device_put_registration(device); + return ret; +} + +static int vfio_group_ioctl_get_status(struct vfio_group *group, + struct vfio_group_status __user *arg) +{ + unsigned long minsz = offsetofend(struct vfio_group_status, flags); + struct vfio_group_status status; + + if (copy_from_user(&status, arg, minsz)) + return -EFAULT; + + if (status.argsz < minsz) + return -EINVAL; + + status.flags = 0; + + mutex_lock(&group->group_lock); + if (!group->iommu_group) { + mutex_unlock(&group->group_lock); + return -ENODEV; + } + + /* + * With the container FD the iommu_group_claim_dma_owner() is done + * during SET_CONTAINER but for IOMMFD this is done during + * VFIO_GROUP_GET_DEVICE_FD. Meaning that with iommufd + * VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due + * to viability. + */ + if (vfio_group_has_iommu(group)) + status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET | + VFIO_GROUP_FLAGS_VIABLE; + else if (!iommu_group_dma_owner_claimed(group->iommu_group)) + status.flags |= VFIO_GROUP_FLAGS_VIABLE; + mutex_unlock(&group->group_lock); + + if (copy_to_user(arg, &status, minsz)) + return -EFAULT; + return 0; +} + +static long vfio_group_fops_unl_ioctl(struct file *filep, + unsigned int cmd, unsigned long arg) +{ + struct vfio_group *group = filep->private_data; + void __user *uarg = (void __user *)arg; + + switch (cmd) { + case VFIO_GROUP_GET_DEVICE_FD: + return vfio_group_ioctl_get_device_fd(group, uarg); + case VFIO_GROUP_GET_STATUS: + return vfio_group_ioctl_get_status(group, uarg); + case VFIO_GROUP_SET_CONTAINER: + return vfio_group_ioctl_set_container(group, uarg); + case VFIO_GROUP_UNSET_CONTAINER: + return vfio_group_ioctl_unset_container(group); + default: + return -ENOTTY; + } +} + +static int vfio_group_fops_open(struct inode *inode, struct file *filep) +{ + struct vfio_group *group = + container_of(inode->i_cdev, struct vfio_group, cdev); + int ret; + + mutex_lock(&group->group_lock); + + /* + * drivers can be zero if this races with vfio_device_remove_group(), it + * will be stable at 0 under the group rwsem + */ + if (refcount_read(&group->drivers) == 0) { + ret = -ENODEV; + goto out_unlock; + } + + if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) { + ret = -EPERM; + goto out_unlock; + } + + /* + * Do we need multiple instances of the group open? Seems not. + */ + if (group->opened_file) { + ret = -EBUSY; + goto out_unlock; + } + group->opened_file = filep; + filep->private_data = group; + ret = 0; +out_unlock: + mutex_unlock(&group->group_lock); + return ret; +} + +static int vfio_group_fops_release(struct inode *inode, struct file *filep) +{ + struct vfio_group *group = filep->private_data; + + filep->private_data = NULL; + + mutex_lock(&group->group_lock); + /* + * Device FDs hold a group file reference, therefore the group release + * is only called when there are no open devices. + */ + WARN_ON(group->notifier.head); + if (group->container) + vfio_group_detach_container(group); + if (group->iommufd) { + iommufd_ctx_put(group->iommufd); + group->iommufd = NULL; + } + group->opened_file = NULL; + mutex_unlock(&group->group_lock); + return 0; +} + +static const struct file_operations vfio_group_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = vfio_group_fops_unl_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .open = vfio_group_fops_open, + .release = vfio_group_fops_release, +}; + +/* + * Group objects - create, release, get, put, search + */ +static struct vfio_group * +vfio_group_find_from_iommu(struct iommu_group *iommu_group) +{ + struct vfio_group *group; + + lockdep_assert_held(&vfio.group_lock); + + /* + * group->iommu_group from the vfio.group_list cannot be NULL + * under the vfio.group_lock. + */ + list_for_each_entry(group, &vfio.group_list, vfio_next) { + if (group->iommu_group == iommu_group) + return group; + } + return NULL; +} + +static void vfio_group_release(struct device *dev) +{ + struct vfio_group *group = container_of(dev, struct vfio_group, dev); + + mutex_destroy(&group->device_lock); + mutex_destroy(&group->group_lock); + WARN_ON(group->iommu_group); + ida_free(&vfio.group_ida, MINOR(group->dev.devt)); + kfree(group); +} + +static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group, + enum vfio_group_type type) +{ + struct vfio_group *group; + int minor; + + group = kzalloc(sizeof(*group), GFP_KERNEL); + if (!group) + return ERR_PTR(-ENOMEM); + + minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL); + if (minor < 0) { + kfree(group); + return ERR_PTR(minor); + } + + device_initialize(&group->dev); + group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor); + group->dev.class = vfio.class; + group->dev.release = vfio_group_release; + cdev_init(&group->cdev, &vfio_group_fops); + group->cdev.owner = THIS_MODULE; + + refcount_set(&group->drivers, 1); + mutex_init(&group->group_lock); + INIT_LIST_HEAD(&group->device_list); + mutex_init(&group->device_lock); + group->iommu_group = iommu_group; + /* put in vfio_group_release() */ + iommu_group_ref_get(iommu_group); + group->type = type; + BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier); + + return group; +} + +static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group, + enum vfio_group_type type) +{ + struct vfio_group *group; + struct vfio_group *ret; + int err; + + lockdep_assert_held(&vfio.group_lock); + + group = vfio_group_alloc(iommu_group, type); + if (IS_ERR(group)) + return group; + + err = dev_set_name(&group->dev, "%s%d", + group->type == VFIO_NO_IOMMU ? "noiommu-" : "", + iommu_group_id(iommu_group)); + if (err) { + ret = ERR_PTR(err); + goto err_put; + } + + err = cdev_device_add(&group->cdev, &group->dev); + if (err) { + ret = ERR_PTR(err); + goto err_put; + } + + list_add(&group->vfio_next, &vfio.group_list); + + return group; + +err_put: + put_device(&group->dev); + return ret; +} + +static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev, + enum vfio_group_type type) +{ + struct iommu_group *iommu_group; + struct vfio_group *group; + int ret; + + iommu_group = iommu_group_alloc(); + if (IS_ERR(iommu_group)) + return ERR_CAST(iommu_group); + + ret = iommu_group_set_name(iommu_group, "vfio-noiommu"); + if (ret) + goto out_put_group; + ret = iommu_group_add_device(iommu_group, dev); + if (ret) + goto out_put_group; + + mutex_lock(&vfio.group_lock); + group = vfio_create_group(iommu_group, type); + mutex_unlock(&vfio.group_lock); + if (IS_ERR(group)) { + ret = PTR_ERR(group); + goto out_remove_device; + } + iommu_group_put(iommu_group); + return group; + +out_remove_device: + iommu_group_remove_device(dev); +out_put_group: + iommu_group_put(iommu_group); + return ERR_PTR(ret); +} + +static bool vfio_group_has_device(struct vfio_group *group, struct device *dev) +{ + struct vfio_device *device; + + mutex_lock(&group->device_lock); + list_for_each_entry(device, &group->device_list, group_next) { + if (device->dev == dev) { + mutex_unlock(&group->device_lock); + return true; + } + } + mutex_unlock(&group->device_lock); + return false; +} + +static struct vfio_group *vfio_group_find_or_alloc(struct device *dev) +{ + struct iommu_group *iommu_group; + struct vfio_group *group; + + iommu_group = iommu_group_get(dev); + if (!iommu_group && vfio_noiommu) { + /* + * With noiommu enabled, create an IOMMU group for devices that + * don't already have one, implying no IOMMU hardware/driver + * exists. Taint the kernel because we're about to give a DMA + * capable device to a user without IOMMU protection. + */ + group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU); + if (!IS_ERR(group)) { + add_taint(TAINT_USER, LOCKDEP_STILL_OK); + dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n"); + } + return group; + } + + if (!iommu_group) + return ERR_PTR(-EINVAL); + + /* + * VFIO always sets IOMMU_CACHE because we offer no way for userspace to + * restore cache coherency. It has to be checked here because it is only + * valid for cases where we are using iommu groups. + */ + if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) { + iommu_group_put(iommu_group); + return ERR_PTR(-EINVAL); + } + + mutex_lock(&vfio.group_lock); + group = vfio_group_find_from_iommu(iommu_group); + if (group) { + if (WARN_ON(vfio_group_has_device(group, dev))) + group = ERR_PTR(-EINVAL); + else + refcount_inc(&group->drivers); + } else { + group = vfio_create_group(iommu_group, VFIO_IOMMU); + } + mutex_unlock(&vfio.group_lock); + + /* The vfio_group holds a reference to the iommu_group */ + iommu_group_put(iommu_group); + return group; +} + +int vfio_device_set_group(struct vfio_device *device, + enum vfio_group_type type) +{ + struct vfio_group *group; + + if (type == VFIO_IOMMU) + group = vfio_group_find_or_alloc(device->dev); + else + group = vfio_noiommu_group_alloc(device->dev, type); + + if (IS_ERR(group)) + return PTR_ERR(group); + + /* Our reference on group is moved to the device */ + device->group = group; + return 0; +} + +void vfio_device_remove_group(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + struct iommu_group *iommu_group; + + if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) + iommu_group_remove_device(device->dev); + + /* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */ + if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock)) + return; + list_del(&group->vfio_next); + + /* + * We could concurrently probe another driver in the group that might + * race vfio_device_remove_group() with vfio_get_group(), so we have to + * ensure that the sysfs is all cleaned up under lock otherwise the + * cdev_device_add() will fail due to the name aready existing. + */ + cdev_device_del(&group->cdev, &group->dev); + + mutex_lock(&group->group_lock); + /* + * These data structures all have paired operations that can only be + * undone when the caller holds a live reference on the device. Since + * all pairs must be undone these WARN_ON's indicate some caller did not + * properly hold the group reference. + */ + WARN_ON(!list_empty(&group->device_list)); + WARN_ON(group->notifier.head); + + /* + * Revoke all users of group->iommu_group. At this point we know there + * are no devices active because we are unplugging the last one. Setting + * iommu_group to NULL blocks all new users. + */ + if (group->container) + vfio_group_detach_container(group); + iommu_group = group->iommu_group; + group->iommu_group = NULL; + mutex_unlock(&group->group_lock); + mutex_unlock(&vfio.group_lock); + + iommu_group_put(iommu_group); + put_device(&group->dev); +} + +void vfio_device_group_register(struct vfio_device *device) +{ + mutex_lock(&device->group->device_lock); + list_add(&device->group_next, &device->group->device_list); + mutex_unlock(&device->group->device_lock); +} + +void vfio_device_group_unregister(struct vfio_device *device) +{ + mutex_lock(&device->group->device_lock); + list_del(&device->group_next); + mutex_unlock(&device->group->device_lock); +} + +int vfio_device_group_use_iommu(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + int ret = 0; + + lockdep_assert_held(&group->group_lock); + + if (WARN_ON(!group->container)) + return -EINVAL; + + ret = vfio_group_use_container(group); + if (ret) + return ret; + vfio_device_container_register(device); + return 0; +} + +void vfio_device_group_unuse_iommu(struct vfio_device *device) +{ + struct vfio_group *group = device->group; + + lockdep_assert_held(&group->group_lock); + + if (WARN_ON(!group->container)) + return; + + vfio_device_container_unregister(device); + vfio_group_unuse_container(group); +} + +bool vfio_device_has_container(struct vfio_device *device) +{ + return device->group->container; +} + +/** + * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file + * @file: VFIO group file + * + * The returned iommu_group is valid as long as a ref is held on the file. This + * returns a reference on the group. This function is deprecated, only the SPAPR + * path in kvm should call it. + */ +struct iommu_group *vfio_file_iommu_group(struct file *file) +{ + struct vfio_group *group = file->private_data; + struct iommu_group *iommu_group = NULL; + + if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU)) + return NULL; + + if (!vfio_file_is_group(file)) + return NULL; + + mutex_lock(&group->group_lock); + if (group->iommu_group) { + iommu_group = group->iommu_group; + iommu_group_ref_get(iommu_group); + } + mutex_unlock(&group->group_lock); + return iommu_group; +} +EXPORT_SYMBOL_GPL(vfio_file_iommu_group); + +/** + * vfio_file_is_group - True if the file is usable with VFIO aPIS + * @file: VFIO group file + */ +bool vfio_file_is_group(struct file *file) +{ + return file->f_op == &vfio_group_fops; +} +EXPORT_SYMBOL_GPL(vfio_file_is_group); + +/** + * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file + * is always CPU cache coherent + * @file: VFIO group file + * + * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop + * bit in DMA transactions. A return of false indicates that the user has + * rights to access additional instructions such as wbinvd on x86. + */ +bool vfio_file_enforced_coherent(struct file *file) +{ + struct vfio_group *group = file->private_data; + struct vfio_device *device; + bool ret = true; + + if (!vfio_file_is_group(file)) + return true; + + /* + * If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then + * any domain later attached to it will also not support it. If the cap + * is set then the iommu_domain eventually attached to the device/group + * must use a domain with enforce_cache_coherency(). + */ + mutex_lock(&group->device_lock); + list_for_each_entry(device, &group->device_list, group_next) { + if (!device_iommu_capable(device->dev, + IOMMU_CAP_ENFORCE_CACHE_COHERENCY)) { + ret = false; + break; + } + } + mutex_unlock(&group->device_lock); + return ret; +} +EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent); + +/** + * vfio_file_set_kvm - Link a kvm with VFIO drivers + * @file: VFIO group file + * @kvm: KVM to link + * + * When a VFIO device is first opened the KVM will be available in + * device->kvm if one was associated with the group. + */ +void vfio_file_set_kvm(struct file *file, struct kvm *kvm) +{ + struct vfio_group *group = file->private_data; + + if (!vfio_file_is_group(file)) + return; + + mutex_lock(&group->group_lock); + group->kvm = kvm; + mutex_unlock(&group->group_lock); +} +EXPORT_SYMBOL_GPL(vfio_file_set_kvm); + +/** + * vfio_file_has_dev - True if the VFIO file is a handle for device + * @file: VFIO file to check + * @device: Device that must be part of the file + * + * Returns true if given file has permission to manipulate the given device. + */ +bool vfio_file_has_dev(struct file *file, struct vfio_device *device) +{ + struct vfio_group *group = file->private_data; + + if (!vfio_file_is_group(file)) + return false; + + return group == device->group; +} +EXPORT_SYMBOL_GPL(vfio_file_has_dev); + +static char *vfio_devnode(const struct device *dev, umode_t *mode) +{ + return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev)); +} + +int __init vfio_group_init(void) +{ + int ret; + + ida_init(&vfio.group_ida); + mutex_init(&vfio.group_lock); + INIT_LIST_HEAD(&vfio.group_list); + + ret = vfio_container_init(); + if (ret) + return ret; + + /* /dev/vfio/$GROUP */ + vfio.class = class_create(THIS_MODULE, "vfio"); + if (IS_ERR(vfio.class)) { + ret = PTR_ERR(vfio.class); + goto err_group_class; + } + + vfio.class->devnode = vfio_devnode; + + ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); + if (ret) + goto err_alloc_chrdev; + return 0; + +err_alloc_chrdev: + class_destroy(vfio.class); + vfio.class = NULL; +err_group_class: + vfio_container_cleanup(); + return ret; +} + +void vfio_group_cleanup(void) +{ + WARN_ON(!list_empty(&vfio.group_list)); + ida_destroy(&vfio.group_ida); + unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); + class_destroy(vfio.class); + vfio.class = NULL; + vfio_container_cleanup(); +} -- cgit v1.2.3