diff options
author | Linus Torvalds | 2022-12-14 09:15:43 -0800 |
---|---|---|
committer | Linus Torvalds | 2022-12-14 09:15:43 -0800 |
commit | 08cdc2157966c07d3f986a097ddaa74cee312751 (patch) | |
tree | dad2562768b49876c642c2505813e90a467ae40a /drivers/vfio | |
parent | aa5ad10f6cca6d42f3fef6cb862e03b220ea19a6 (diff) | |
parent | d6c55c0a20e5059abdde81713ddf6324a946eb3c (diff) |
Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd
Pull iommufd implementation from Jason Gunthorpe:
"iommufd is the user API to control the IOMMU subsystem as it relates
to managing IO page tables that point at user space memory.
It takes over from drivers/vfio/vfio_iommu_type1.c (aka the VFIO
container) which is the VFIO specific interface for a similar idea.
We see a broad need for extended features, some being highly IOMMU
device specific:
- Binding iommu_domain's to PASID/SSID
- Userspace IO page tables, for ARM, x86 and S390
- Kernel bypassed invalidation of user page tables
- Re-use of the KVM page table in the IOMMU
- Dirty page tracking in the IOMMU
- Runtime Increase/Decrease of IOPTE size
- PRI support with faults resolved in userspace
Many of these HW features exist to support VM use cases - for instance
the combination of PASID, PRI and Userspace IO Page Tables allows an
implementation of DMA Shared Virtual Addressing (vSVA) within a guest.
Dirty tracking enables VM live migration with SRIOV devices and PASID
support allow creating "scalable IOV" devices, among other things.
As these features are fundamental to a VM platform they need to be
uniformly exposed to all the driver families that do DMA into VMs,
which is currently VFIO and VDPA"
For more background, see the extended explanations in Jason's pull request:
https://lore.kernel.org/lkml/Y5dzTU8dlmXTbzoJ@nvidia.com/
* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (62 commits)
iommufd: Change the order of MSI setup
iommufd: Improve a few unclear bits of code
iommufd: Fix comment typos
vfio: Move vfio group specific code into group.c
vfio: Refactor dma APIs for emulated devices
vfio: Wrap vfio group module init/clean code into helpers
vfio: Refactor vfio_device open and close
vfio: Make vfio_device_open() truly device specific
vfio: Swap order of vfio_device_container_register() and open_device()
vfio: Set device->group in helper function
vfio: Create wrappers for group register/unregister
vfio: Move the sanity check of the group to vfio_create_group()
vfio: Simplify vfio_create_group()
iommufd: Allow iommufd to supply /dev/vfio/vfio
vfio: Make vfio_container optionally compiled
vfio: Move container related MODULE_ALIAS statements into container.c
vfio-iommufd: Support iommufd for emulated VFIO devices
vfio-iommufd: Support iommufd for physical VFIO devices
vfio-iommufd: Allow iommufd to be used in place of a container fd
vfio: Use IOMMU_CAP_ENFORCE_CACHE_COHERENCY for vfio_file_enforced_coherent()
...
Diffstat (limited to 'drivers/vfio')
-rw-r--r-- | drivers/vfio/Kconfig | 36 | ||||
-rw-r--r-- | drivers/vfio/Makefile | 6 | ||||
-rw-r--r-- | drivers/vfio/container.c | 145 | ||||
-rw-r--r-- | drivers/vfio/fsl-mc/vfio_fsl_mc.c | 3 | ||||
-rw-r--r-- | drivers/vfio/group.c | 877 | ||||
-rw-r--r-- | drivers/vfio/iommufd.c | 158 | ||||
-rw-r--r-- | drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 6 | ||||
-rw-r--r-- | drivers/vfio/pci/mlx5/main.c | 3 | ||||
-rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 3 | ||||
-rw-r--r-- | drivers/vfio/platform/vfio_amba.c | 3 | ||||
-rw-r--r-- | drivers/vfio/platform/vfio_platform.c | 3 | ||||
-rw-r--r-- | drivers/vfio/vfio.h | 120 | ||||
-rw-r--r-- | drivers/vfio/vfio_main.c | 983 |
13 files changed, 1434 insertions, 912 deletions
diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig index 86c381ceb9a1..286c1663bd75 100644 --- a/drivers/vfio/Kconfig +++ b/drivers/vfio/Kconfig @@ -2,8 +2,9 @@ menuconfig VFIO tristate "VFIO Non-Privileged userspace driver framework" select IOMMU_API - select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64) + depends on IOMMUFD || !IOMMUFD select INTERVAL_TREE + select VFIO_CONTAINER if IOMMUFD=n help VFIO provides a framework for secure userspace device drivers. See Documentation/driver-api/vfio.rst for more details. @@ -11,6 +12,18 @@ menuconfig VFIO If you don't know what to do here, say N. if VFIO +config VFIO_CONTAINER + bool "Support for the VFIO container /dev/vfio/vfio" + select VFIO_IOMMU_TYPE1 if MMU && (X86 || S390 || ARM || ARM64) + default y + help + The VFIO container is the classic interface to VFIO for establishing + IOMMU mappings. If N is selected here then IOMMUFD must be used to + manage the mappings. + + Unless testing IOMMUFD say Y here. + +if VFIO_CONTAINER config VFIO_IOMMU_TYPE1 tristate default n @@ -20,16 +33,6 @@ config VFIO_IOMMU_SPAPR_TCE depends on SPAPR_TCE_IOMMU default VFIO -config VFIO_SPAPR_EEH - tristate - depends on EEH && VFIO_IOMMU_SPAPR_TCE - default VFIO - -config VFIO_VIRQFD - tristate - select EVENTFD - default n - config VFIO_NOIOMMU bool "VFIO No-IOMMU support" help @@ -43,6 +46,17 @@ config VFIO_NOIOMMU this mode since there is no IOMMU to provide DMA translation. If you don't know what to do here, say N. +endif + +config VFIO_SPAPR_EEH + tristate + depends on EEH && VFIO_IOMMU_SPAPR_TCE + default VFIO + +config VFIO_VIRQFD + tristate + select EVENTFD + default n source "drivers/vfio/pci/Kconfig" source "drivers/vfio/platform/Kconfig" diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile index b693a1169286..3783db7e8082 100644 --- a/drivers/vfio/Makefile +++ b/drivers/vfio/Makefile @@ -4,8 +4,10 @@ vfio_virqfd-y := virqfd.o obj-$(CONFIG_VFIO) += vfio.o vfio-y += vfio_main.o \ - iova_bitmap.o \ - container.o + group.o \ + iova_bitmap.o +vfio-$(CONFIG_IOMMUFD) += iommufd.o +vfio-$(CONFIG_VFIO_CONTAINER) += container.o obj-$(CONFIG_VFIO_VIRQFD) += vfio_virqfd.o obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o diff --git a/drivers/vfio/container.c b/drivers/vfio/container.c index d74164abbf40..b7a9560ab25e 100644 --- a/drivers/vfio/container.c +++ b/drivers/vfio/container.c @@ -188,8 +188,9 @@ void vfio_device_container_unregister(struct vfio_device *device) device->group->container->iommu_data, device); } -long vfio_container_ioctl_check_extension(struct vfio_container *container, - unsigned long arg) +static long +vfio_container_ioctl_check_extension(struct vfio_container *container, + unsigned long arg) { struct vfio_iommu_driver *driver; long ret = 0; @@ -511,14 +512,15 @@ void vfio_group_detach_container(struct vfio_group *group) vfio_container_put(container); } -int vfio_device_assign_container(struct vfio_device *device) +int vfio_group_use_container(struct vfio_group *group) { - struct vfio_group *group = device->group; - lockdep_assert_held(&group->group_lock); - if (!group->container || !group->container->iommu_driver || - WARN_ON(!group->container_users)) + /* + * The container fd has been assigned with VFIO_GROUP_SET_CONTAINER but + * VFIO_SET_IOMMU hasn't been done yet. + */ + if (!group->container->iommu_driver) return -EINVAL; if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) @@ -529,122 +531,56 @@ int vfio_device_assign_container(struct vfio_device *device) return 0; } -void vfio_device_unassign_container(struct vfio_device *device) +void vfio_group_unuse_container(struct vfio_group *group) { - mutex_lock(&device->group->group_lock); - WARN_ON(device->group->container_users <= 1); - device->group->container_users--; - fput(device->group->opened_file); - mutex_unlock(&device->group->group_lock); + lockdep_assert_held(&group->group_lock); + + WARN_ON(group->container_users <= 1); + group->container_users--; + fput(group->opened_file); } -/* - * Pin contiguous user pages and return their associated host pages for local - * domain only. - * @device [in] : device - * @iova [in] : starting IOVA of user pages to be pinned. - * @npage [in] : count of pages to be pinned. This count should not - * be greater than VFIO_PIN_PAGES_MAX_ENTRIES. - * @prot [in] : protection flags - * @pages[out] : array of host pages - * Return error or number of pages pinned. - * - * A driver may only call this function if the vfio_device was created - * by vfio_register_emulated_iommu_dev(). - */ -int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova, - int npage, int prot, struct page **pages) +int vfio_device_container_pin_pages(struct vfio_device *device, + dma_addr_t iova, int npage, + int prot, struct page **pages) { - struct vfio_container *container; - struct vfio_group *group = device->group; - struct vfio_iommu_driver *driver; - int ret; - - if (!pages || !npage || !vfio_assert_device_open(device)) - return -EINVAL; + struct vfio_container *container = device->group->container; + struct iommu_group *iommu_group = device->group->iommu_group; + struct vfio_iommu_driver *driver = container->iommu_driver; if (npage > VFIO_PIN_PAGES_MAX_ENTRIES) return -E2BIG; - /* group->container cannot change while a vfio device is open */ - container = group->container; - driver = container->iommu_driver; - if (likely(driver && driver->ops->pin_pages)) - ret = driver->ops->pin_pages(container->iommu_data, - group->iommu_group, iova, - npage, prot, pages); - else - ret = -ENOTTY; - - return ret; + if (unlikely(!driver || !driver->ops->pin_pages)) + return -ENOTTY; + return driver->ops->pin_pages(container->iommu_data, iommu_group, iova, + npage, prot, pages); } -EXPORT_SYMBOL(vfio_pin_pages); -/* - * Unpin contiguous host pages for local domain only. - * @device [in] : device - * @iova [in] : starting address of user pages to be unpinned. - * @npage [in] : count of pages to be unpinned. This count should not - * be greater than VFIO_PIN_PAGES_MAX_ENTRIES. - */ -void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage) +void vfio_device_container_unpin_pages(struct vfio_device *device, + dma_addr_t iova, int npage) { - struct vfio_container *container; - struct vfio_iommu_driver *driver; + struct vfio_container *container = device->group->container; if (WARN_ON(npage <= 0 || npage > VFIO_PIN_PAGES_MAX_ENTRIES)) return; - if (WARN_ON(!vfio_assert_device_open(device))) - return; - - /* group->container cannot change while a vfio device is open */ - container = device->group->container; - driver = container->iommu_driver; - - driver->ops->unpin_pages(container->iommu_data, iova, npage); + container->iommu_driver->ops->unpin_pages(container->iommu_data, iova, + npage); } -EXPORT_SYMBOL(vfio_unpin_pages); -/* - * This interface allows the CPUs to perform some sort of virtual DMA on - * behalf of the device. - * - * CPUs read/write from/into a range of IOVAs pointing to user space memory - * into/from a kernel buffer. - * - * As the read/write of user space memory is conducted via the CPUs and is - * not a real device DMA, it is not necessary to pin the user space memory. - * - * @device [in] : VFIO device - * @iova [in] : base IOVA of a user space buffer - * @data [in] : pointer to kernel buffer - * @len [in] : kernel buffer length - * @write : indicate read or write - * Return error code on failure or 0 on success. - */ -int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data, - size_t len, bool write) +int vfio_device_container_dma_rw(struct vfio_device *device, + dma_addr_t iova, void *data, + size_t len, bool write) { - struct vfio_container *container; - struct vfio_iommu_driver *driver; - int ret = 0; - - if (!data || len <= 0 || !vfio_assert_device_open(device)) - return -EINVAL; - - /* group->container cannot change while a vfio device is open */ - container = device->group->container; - driver = container->iommu_driver; + struct vfio_container *container = device->group->container; + struct vfio_iommu_driver *driver = container->iommu_driver; - if (likely(driver && driver->ops->dma_rw)) - ret = driver->ops->dma_rw(container->iommu_data, - iova, data, len, write); - else - ret = -ENOTTY; - return ret; + if (unlikely(!driver || !driver->ops->dma_rw)) + return -ENOTTY; + return driver->ops->dma_rw(container->iommu_data, iova, data, len, + write); } -EXPORT_SYMBOL(vfio_dma_rw); int __init vfio_container_init(void) { @@ -678,3 +614,6 @@ void vfio_container_cleanup(void) misc_deregister(&vfio_dev); mutex_destroy(&vfio.iommu_drivers_lock); } + +MODULE_ALIAS_MISCDEV(VFIO_MINOR); +MODULE_ALIAS("devname:vfio/vfio"); diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c index b16874e913e4..5cd4bb476440 100644 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c @@ -592,6 +592,9 @@ static const struct vfio_device_ops vfio_fsl_mc_ops = { .read = vfio_fsl_mc_read, .write = vfio_fsl_mc_write, .mmap = vfio_fsl_mc_mmap, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, }; static struct fsl_mc_driver vfio_fsl_mc_driver = { diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c new file mode 100644 index 000000000000..c5d8bf10495e --- /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 <alex.williamson@redhat.com> + * + * Derived from original vfio: + * Copyright 2010 Cisco Systems, Inc. All rights reserved. + * Author: Tom Lyon, pugs@cisco.com + */ + +#include <linux/vfio.h> +#include <linux/iommufd.h> +#include <linux/anon_inodes.h> +#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(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(); +} diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c new file mode 100644 index 000000000000..4f82a6fa7c6c --- /dev/null +++ b/drivers/vfio/iommufd.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES + */ +#include <linux/vfio.h> +#include <linux/iommufd.h> + +#include "vfio.h" + +MODULE_IMPORT_NS(IOMMUFD); +MODULE_IMPORT_NS(IOMMUFD_VFIO); + +int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx) +{ + u32 ioas_id; + u32 device_id; + int ret; + + lockdep_assert_held(&vdev->dev_set->lock); + + /* + * If the driver doesn't provide this op then it means the device does + * not do DMA at all. So nothing to do. + */ + if (!vdev->ops->bind_iommufd) + return 0; + + ret = vdev->ops->bind_iommufd(vdev, ictx, &device_id); + if (ret) + return ret; + + ret = iommufd_vfio_compat_ioas_id(ictx, &ioas_id); + if (ret) + goto err_unbind; + ret = vdev->ops->attach_ioas(vdev, &ioas_id); + if (ret) + goto err_unbind; + + /* + * The legacy path has no way to return the device id or the selected + * pt_id + */ + return 0; + +err_unbind: + if (vdev->ops->unbind_iommufd) + vdev->ops->unbind_iommufd(vdev); + return ret; +} + +void vfio_iommufd_unbind(struct vfio_device *vdev) +{ + lockdep_assert_held(&vdev->dev_set->lock); + + if (vdev->ops->unbind_iommufd) + vdev->ops->unbind_iommufd(vdev); +} + +/* + * The physical standard ops mean that the iommufd_device is bound to the + * physical device vdev->dev that was provided to vfio_init_group_dev(). Drivers + * using this ops set should call vfio_register_group_dev() + */ +int vfio_iommufd_physical_bind(struct vfio_device *vdev, + struct iommufd_ctx *ictx, u32 *out_device_id) +{ + struct iommufd_device *idev; + + idev = iommufd_device_bind(ictx, vdev->dev, out_device_id); + if (IS_ERR(idev)) + return PTR_ERR(idev); + vdev->iommufd_device = idev; + return 0; +} +EXPORT_SYMBOL_GPL(vfio_iommufd_physical_bind); + +void vfio_iommufd_physical_unbind(struct vfio_device *vdev) +{ + lockdep_assert_held(&vdev->dev_set->lock); + + if (vdev->iommufd_attached) { + iommufd_device_detach(vdev->iommufd_device); + vdev->iommufd_attached = false; + } + iommufd_device_unbind(vdev->iommufd_device); + vdev->iommufd_device = NULL; +} +EXPORT_SYMBOL_GPL(vfio_iommufd_physical_unbind); + +int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id) +{ + int rc; + + rc = iommufd_device_attach(vdev->iommufd_device, pt_id); + if (rc) + return rc; + vdev->iommufd_attached = true; + return 0; +} +EXPORT_SYMBOL_GPL(vfio_iommufd_physical_attach_ioas); + +/* + * The emulated standard ops mean that vfio_device is going to use the + * "mdev path" and will call vfio_pin_pages()/vfio_dma_rw(). Drivers using this + * ops set should call vfio_register_emulated_iommu_dev(). + */ + +static void vfio_emulated_unmap(void *data, unsigned long iova, + unsigned long length) +{ + struct vfio_device *vdev = data; + + vdev->ops->dma_unmap(vdev, iova, length); +} + +static const struct iommufd_access_ops vfio_user_ops = { + .needs_pin_pages = 1, + .unmap = vfio_emulated_unmap, +}; + +int vfio_iommufd_emulated_bind(struct vfio_device *vdev, + struct iommufd_ctx *ictx, u32 *out_device_id) +{ + lockdep_assert_held(&vdev->dev_set->lock); + + vdev->iommufd_ictx = ictx; + iommufd_ctx_get(ictx); + return 0; +} +EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_bind); + +void vfio_iommufd_emulated_unbind(struct vfio_device *vdev) +{ + lockdep_assert_held(&vdev->dev_set->lock); + + if (vdev->iommufd_access) { + iommufd_access_destroy(vdev->iommufd_access); + vdev->iommufd_access = NULL; + } + iommufd_ctx_put(vdev->iommufd_ictx); + vdev->iommufd_ictx = NULL; +} +EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_unbind); + +int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id) +{ + struct iommufd_access *user; + + lockdep_assert_held(&vdev->dev_set->lock); + + user = iommufd_access_create(vdev->iommufd_ictx, *pt_id, &vfio_user_ops, + vdev); + if (IS_ERR(user)) + return PTR_ERR(user); + vdev->iommufd_access = user; + return 0; +} +EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_attach_ioas); diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c index 39eeca18a0f7..40019b11c5a9 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c @@ -1246,6 +1246,9 @@ static const struct vfio_device_ops hisi_acc_vfio_pci_migrn_ops = { .mmap = hisi_acc_vfio_pci_mmap, .request = vfio_pci_core_request, .match = vfio_pci_core_match, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, }; static const struct vfio_device_ops hisi_acc_vfio_pci_ops = { @@ -1261,6 +1264,9 @@ static const struct vfio_device_ops hisi_acc_vfio_pci_ops = { .mmap = vfio_pci_core_mmap, .request = vfio_pci_core_request, .match = vfio_pci_core_match, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, }; static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c index fd6ccb8454a2..32d1f38d351e 100644 --- a/drivers/vfio/pci/mlx5/main.c +++ b/drivers/vfio/pci/mlx5/main.c @@ -623,6 +623,9 @@ static const struct vfio_device_ops mlx5vf_pci_ops = { .mmap = vfio_pci_core_mmap, .request = vfio_pci_core_request, .match = vfio_pci_core_match, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, }; static int mlx5vf_pci_probe(struct pci_dev *pdev, diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 1d4919edfbde..29091ee2e984 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -138,6 +138,9 @@ static const struct vfio_device_ops vfio_pci_ops = { .mmap = vfio_pci_core_mmap, .request = vfio_pci_core_request, .match = vfio_pci_core_match, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, }; static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) diff --git a/drivers/vfio/platform/vfio_amba.c b/drivers/vfio/platform/vfio_amba.c index eaea63e5294c..5a046098d0bd 100644 --- a/drivers/vfio/platform/vfio_amba.c +++ b/drivers/vfio/platform/vfio_amba.c @@ -117,6 +117,9 @@ static const struct vfio_device_ops vfio_amba_ops = { .read = vfio_platform_read, .write = vfio_platform_write, .mmap = vfio_platform_mmap, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, }; static const struct amba_id pl330_ids[] = { diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c index 82cedcebfd90..b87c3b708783 100644 --- a/drivers/vfio/platform/vfio_platform.c +++ b/drivers/vfio/platform/vfio_platform.c @@ -106,6 +106,9 @@ static const struct vfio_device_ops vfio_platform_ops = { .read = vfio_platform_read, .write = vfio_platform_write, .mmap = vfio_platform_mmap, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, }; static struct platform_driver vfio_platform_driver = { diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h index bcad54bbab08..2e05418fd18d 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -6,14 +6,25 @@ #ifndef __VFIO_VFIO_H__ #define __VFIO_VFIO_H__ +#include <linux/file.h> #include <linux/device.h> #include <linux/cdev.h> #include <linux/module.h> +struct iommufd_ctx; struct iommu_group; struct vfio_device; struct vfio_container; +void vfio_device_put_registration(struct vfio_device *device); +bool vfio_device_try_get_registration(struct vfio_device *device); +int vfio_device_open(struct vfio_device *device, + struct iommufd_ctx *iommufd, struct kvm *kvm); +void vfio_device_close(struct vfio_device *device, + struct iommufd_ctx *iommufd); + +extern const struct file_operations vfio_device_fops; + enum vfio_group_type { /* * Physical device with IOMMU backing. @@ -54,14 +65,30 @@ struct vfio_group { struct list_head device_list; struct mutex device_lock; struct list_head vfio_next; +#if IS_ENABLED(CONFIG_VFIO_CONTAINER) struct list_head container_next; +#endif enum vfio_group_type type; struct mutex group_lock; struct kvm *kvm; struct file *opened_file; struct blocking_notifier_head notifier; + struct iommufd_ctx *iommufd; }; +int vfio_device_set_group(struct vfio_device *device, + enum vfio_group_type type); +void vfio_device_remove_group(struct vfio_device *device); +void vfio_device_group_register(struct vfio_device *device); +void vfio_device_group_unregister(struct vfio_device *device); +int vfio_device_group_use_iommu(struct vfio_device *device); +void vfio_device_group_unuse_iommu(struct vfio_device *device); +void vfio_device_group_close(struct vfio_device *device); +bool vfio_device_has_container(struct vfio_device *device); +int __init vfio_group_init(void); +void vfio_group_cleanup(void); + +#if IS_ENABLED(CONFIG_VFIO_CONTAINER) /* events for the backend driver notify callback */ enum vfio_iommu_notify_type { VFIO_IOMMU_CONTAINER_CLOSE = 0, @@ -109,20 +136,101 @@ struct vfio_iommu_driver { int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops); void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops); -bool vfio_assert_device_open(struct vfio_device *device); - struct vfio_container *vfio_container_from_file(struct file *filep); -int vfio_device_assign_container(struct vfio_device *device); -void vfio_device_unassign_container(struct vfio_device *device); +int vfio_group_use_container(struct vfio_group *group); +void vfio_group_unuse_container(struct vfio_group *group); int vfio_container_attach_group(struct vfio_container *container, struct vfio_group *group); void vfio_group_detach_container(struct vfio_group *group); void vfio_device_container_register(struct vfio_device *device); void vfio_device_container_unregister(struct vfio_device *device); -long vfio_container_ioctl_check_extension(struct vfio_container *container, - unsigned long arg); +int vfio_device_container_pin_pages(struct vfio_device *device, + dma_addr_t iova, int npage, + int prot, struct page **pages); +void vfio_device_container_unpin_pages(struct vfio_device *device, + dma_addr_t iova, int npage); +int vfio_device_container_dma_rw(struct vfio_device *device, + dma_addr_t iova, void *data, + size_t len, bool write); + int __init vfio_container_init(void); void vfio_container_cleanup(void); +#else +static inline struct vfio_container * +vfio_container_from_file(struct file *filep) +{ + return NULL; +} + +static inline int vfio_group_use_container(struct vfio_group *group) +{ + return -EOPNOTSUPP; +} + +static inline void vfio_group_unuse_container(struct vfio_group *group) +{ +} + +static inline int vfio_container_attach_group(struct vfio_container *container, + struct vfio_group *group) +{ + return -EOPNOTSUPP; +} + +static inline void vfio_group_detach_container(struct vfio_group *group) +{ +} + +static inline void vfio_device_container_register(struct vfio_device *device) +{ +} + +static inline void vfio_device_container_unregister(struct vfio_device *device) +{ +} + +static inline int vfio_device_container_pin_pages(struct vfio_device *device, + dma_addr_t iova, int npage, + int prot, struct page **pages) +{ + return -EOPNOTSUPP; +} + +static inline void vfio_device_container_unpin_pages(struct vfio_device *device, + dma_addr_t iova, int npage) +{ +} + +static inline int vfio_device_container_dma_rw(struct vfio_device *device, + dma_addr_t iova, void *data, + size_t len, bool write) +{ + return -EOPNOTSUPP; +} + +static inline int vfio_container_init(void) +{ + return 0; +} +static inline void vfio_container_cleanup(void) +{ +} +#endif + +#if IS_ENABLED(CONFIG_IOMMUFD) +int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx); +void vfio_iommufd_unbind(struct vfio_device *device); +#else +static inline int vfio_iommufd_bind(struct vfio_device *device, + struct iommufd_ctx *ictx) +{ + return -EOPNOTSUPP; +} + +static inline void vfio_iommufd_unbind(struct vfio_device *device) +{ +} +#endif #ifdef CONFIG_VFIO_NOIOMMU extern bool vfio_noiommu __read_mostly; diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 6e8804fe0095..e21ff965141e 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -13,8 +13,6 @@ #include <linux/cdev.h> #include <linux/compat.h> #include <linux/device.h> -#include <linux/file.h> -#include <linux/anon_inodes.h> #include <linux/fs.h> #include <linux/idr.h> #include <linux/iommu.h> @@ -35,6 +33,7 @@ #include <linux/pm_runtime.h> #include <linux/interval_tree.h> #include <linux/iova_bitmap.h> +#include <linux/iommufd.h> #include "vfio.h" #define DRIVER_VERSION "0.3" @@ -42,17 +41,11 @@ #define DRIVER_DESC "VFIO - User Level meta-driver" 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; struct class *device_class; struct ida device_ida; } vfio; static DEFINE_XARRAY(vfio_device_set_xa); -static const struct file_operations vfio_group_fops; int vfio_assign_device_set(struct vfio_device *device, void *set_id) { @@ -139,207 +132,20 @@ unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set) EXPORT_SYMBOL_GPL(vfio_device_set_open_count); /* - * Group objects - create, release, get, put, search - */ -static struct vfio_group * -__vfio_group_get_from_iommu(struct iommu_group *iommu_group) -{ - struct vfio_group *group; - - /* - * 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) { - refcount_inc(&group->drivers); - return group; - } - } - return NULL; -} - -static struct vfio_group * -vfio_group_get_from_iommu(struct iommu_group *iommu_group) -{ - struct vfio_group *group; - - mutex_lock(&vfio.group_lock); - group = __vfio_group_get_from_iommu(iommu_group); - mutex_unlock(&vfio.group_lock); - return group; -} - -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; - - 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; - } - - mutex_lock(&vfio.group_lock); - - /* Did we race creating this group? */ - ret = __vfio_group_get_from_iommu(iommu_group); - if (ret) - goto err_unlock; - - err = cdev_device_add(&group->cdev, &group->dev); - if (err) { - ret = ERR_PTR(err); - goto err_unlock; - } - - list_add(&group->vfio_next, &vfio.group_list); - - mutex_unlock(&vfio.group_lock); - return group; - -err_unlock: - mutex_unlock(&vfio.group_lock); -err_put: - put_device(&group->dev); - return ret; -} - -static 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); -} - -/* * Device objects - create, release, get, put, search */ /* Device reference always implies a group reference */ -static void vfio_device_put_registration(struct vfio_device *device) +void vfio_device_put_registration(struct vfio_device *device) { if (refcount_dec_and_test(&device->refcount)) complete(&device->comp); } -static bool vfio_device_try_get_registration(struct vfio_device *device) +bool vfio_device_try_get_registration(struct vfio_device *device) { return refcount_inc_not_zero(&device->refcount); } -static struct vfio_device *vfio_group_get_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 && - vfio_device_try_get_registration(device)) { - mutex_unlock(&group->device_lock); - return device; - } - } - mutex_unlock(&group->device_lock); - return NULL; -} - /* * VFIO driver API */ @@ -448,94 +254,15 @@ void vfio_free_device(struct vfio_device *device) } EXPORT_SYMBOL_GPL(vfio_free_device); -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; - - group = vfio_create_group(iommu_group, type); - 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 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); - } - - group = vfio_group_get_from_iommu(iommu_group); - if (!group) - group = vfio_create_group(iommu_group, VFIO_IOMMU); - - /* The vfio_group holds a reference to the iommu_group */ - iommu_group_put(iommu_group); - return group; -} - static int __vfio_register_dev(struct vfio_device *device, - struct vfio_group *group) + enum vfio_group_type type) { - struct vfio_device *existing_device; int ret; - /* - * In all cases group is the output of one of the group allocation - * functions and we have group->drivers incremented for us. - */ - if (IS_ERR(group)) - return PTR_ERR(group); + if (WARN_ON(device->ops->bind_iommufd && + (!device->ops->unbind_iommufd || + !device->ops->attach_ioas))) + return -EINVAL; /* * If the driver doesn't specify a set then the device is added to a @@ -544,25 +271,13 @@ static int __vfio_register_dev(struct vfio_device *device, if (!device->dev_set) vfio_assign_device_set(device, device); - existing_device = vfio_group_get_device(group, device->dev); - if (existing_device) { - /* - * group->iommu_group is non-NULL because we hold the drivers - * refcount. - */ - dev_WARN(device->dev, "Device already exists on group %d\n", - iommu_group_id(group->iommu_group)); - vfio_device_put_registration(existing_device); - ret = -EBUSY; - goto err_out; - } - - /* Our reference on group is moved to the device */ - device->group = group; - ret = dev_set_name(&device->device, "vfio%d", device->index); if (ret) - goto err_out; + return ret; + + ret = vfio_device_set_group(device, type); + if (ret) + return ret; ret = device_add(&device->device); if (ret) @@ -571,9 +286,7 @@ static int __vfio_register_dev(struct vfio_device *device, /* Refcounting can't start until the driver calls register */ refcount_set(&device->refcount, 1); - mutex_lock(&group->device_lock); - list_add(&device->group_next, &group->device_list); - mutex_unlock(&group->device_lock); + vfio_device_group_register(device); return 0; err_out: @@ -583,8 +296,7 @@ err_out: int vfio_register_group_dev(struct vfio_device *device) { - return __vfio_register_dev(device, - vfio_group_find_or_alloc(device->dev)); + return __vfio_register_dev(device, VFIO_IOMMU); } EXPORT_SYMBOL_GPL(vfio_register_group_dev); @@ -594,46 +306,15 @@ EXPORT_SYMBOL_GPL(vfio_register_group_dev); */ int vfio_register_emulated_iommu_dev(struct vfio_device *device) { - return __vfio_register_dev(device, - vfio_noiommu_group_alloc(device->dev, VFIO_EMULATED_IOMMU)); + return __vfio_register_dev(device, VFIO_EMULATED_IOMMU); } EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev); -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; -} - /* * Decrement the device reference count and wait for the device to be * removed. Open file descriptors for the device... */ void vfio_unregister_group_dev(struct vfio_device *device) { - struct vfio_group *group = device->group; unsigned int i = 0; bool interrupted = false; long rc; @@ -661,333 +342,101 @@ void vfio_unregister_group_dev(struct vfio_device *device) } } - mutex_lock(&group->device_lock); - list_del(&device->group_next); - mutex_unlock(&group->device_lock); + vfio_device_group_unregister(device); /* Balances device_add in register path */ device_del(&device->device); + /* Balances vfio_device_set_group in register path */ vfio_device_remove_group(device); } EXPORT_SYMBOL_GPL(vfio_unregister_group_dev); -/* - * VFIO Group fd, /dev/vfio/$GROUP - */ -/* - * 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) +/* true if the vfio_device has open_device() called but not close_device() */ +static bool vfio_assert_device_open(struct vfio_device *device) { - int ret = 0; - - mutex_lock(&group->group_lock); - if (!group->container) { - ret = -EINVAL; - goto out_unlock; - } - if (group->container_users != 1) { - ret = -EBUSY; - goto out_unlock; - } - vfio_group_detach_container(group); - -out_unlock: - mutex_unlock(&group->group_lock); - return ret; + return !WARN_ON_ONCE(!READ_ONCE(device->open_count)); } -static int vfio_group_ioctl_set_container(struct vfio_group *group, - int __user *arg) +static int vfio_device_first_open(struct vfio_device *device, + struct iommufd_ctx *iommufd, struct kvm *kvm) { - struct vfio_container *container; - struct fd f; int ret; - int fd; - if (get_user(fd, arg)) - return -EFAULT; + lockdep_assert_held(&device->dev_set->lock); - f = fdget(fd); - if (!f.file) - return -EBADF; + if (!try_module_get(device->dev->driver->owner)) + return -ENODEV; - mutex_lock(&group->group_lock); - if (group->container || WARN_ON(group->container_users)) { - ret = -EINVAL; - goto out_unlock; - } - if (!group->iommu_group) { - ret = -ENODEV; - goto out_unlock; - } + if (iommufd) + ret = vfio_iommufd_bind(device, iommufd); + else + ret = vfio_device_group_use_iommu(device); + if (ret) + goto err_module_put; - container = vfio_container_from_file(f.file); - ret = -EINVAL; - if (container) { - ret = vfio_container_attach_group(container, group); - goto out_unlock; + device->kvm = kvm; + if (device->ops->open_device) { + ret = device->ops->open_device(device); + if (ret) + goto err_unuse_iommu; } + return 0; -out_unlock: - mutex_unlock(&group->group_lock); - fdput(f); +err_unuse_iommu: + device->kvm = NULL; + if (iommufd) + vfio_iommufd_unbind(device); + else + vfio_device_group_unuse_iommu(device); +err_module_put: + module_put(device->dev->driver->owner); return ret; } -static const struct file_operations vfio_device_fops; - -/* true if the vfio_device has open_device() called but not close_device() */ -bool vfio_assert_device_open(struct vfio_device *device) +static void vfio_device_last_close(struct vfio_device *device, + struct iommufd_ctx *iommufd) { - return !WARN_ON_ONCE(!READ_ONCE(device->open_count)); + lockdep_assert_held(&device->dev_set->lock); + + if (device->ops->close_device) + device->ops->close_device(device); + device->kvm = NULL; + if (iommufd) + vfio_iommufd_unbind(device); + else + vfio_device_group_unuse_iommu(device); + module_put(device->dev->driver->owner); } -static struct file *vfio_device_open(struct vfio_device *device) +int vfio_device_open(struct vfio_device *device, + struct iommufd_ctx *iommufd, struct kvm *kvm) { - struct file *filep; - int ret; - - mutex_lock(&device->group->group_lock); - ret = vfio_device_assign_container(device); - mutex_unlock(&device->group->group_lock); - if (ret) - return ERR_PTR(ret); - - if (!try_module_get(device->dev->driver->owner)) { - ret = -ENODEV; - goto err_unassign_container; - } + int ret = 0; mutex_lock(&device->dev_set->lock); device->open_count++; if (device->open_count == 1) { - /* - * Here we pass the KVM pointer with the group under the read - * lock. If the device driver will use it, it must obtain a - * reference and release it during close_device. - */ - mutex_lock(&device->group->group_lock); - device->kvm = device->group->kvm; - - if (device->ops->open_device) { - ret = device->ops->open_device(device); - if (ret) - goto err_undo_count; - } - vfio_device_container_register(device); - mutex_unlock(&device->group->group_lock); - } - mutex_unlock(&device->dev_set->lock); - - /* - * 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: - mutex_lock(&device->dev_set->lock); - mutex_lock(&device->group->group_lock); - if (device->open_count == 1) { - if (device->ops->close_device) - device->ops->close_device(device); - - vfio_device_container_unregister(device); + ret = vfio_device_first_open(device, iommufd, kvm); + if (ret) + device->open_count--; } -err_undo_count: - mutex_unlock(&device->group->group_lock); - device->open_count--; - if (device->open_count == 0 && device->kvm) - device->kvm = NULL; mutex_unlock(&device->dev_set->lock); - module_put(device->dev->driver->owner); -err_unassign_container: - vfio_device_unassign_container(device); - 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(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; - } - - if (group->container) - 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) +void vfio_device_close(struct vfio_device *device, + struct iommufd_ctx *iommufd) { - 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); - group->opened_file = NULL; - mutex_unlock(&group->group_lock); - return 0; + mutex_lock(&device->dev_set->lock); + vfio_assert_device_open(device); + if (device->open_count == 1) + vfio_device_last_close(device, iommufd); + device->open_count--; + mutex_unlock(&device->dev_set->lock); } -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, -}; - /* * Wrapper around pm_runtime_resume_and_get(). * Return error code on failure or 0 on success. @@ -1028,24 +477,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep) { struct vfio_device *device = filep->private_data; - mutex_lock(&device->dev_set->lock); - vfio_assert_device_open(device); - mutex_lock(&device->group->group_lock); - if (device->open_count == 1) { - if (device->ops->close_device) - device->ops->close_device(device); - - vfio_device_container_unregister(device); - } - mutex_unlock(&device->group->group_lock); - device->open_count--; - if (device->open_count == 0) - device->kvm = NULL; - mutex_unlock(&device->dev_set->lock); - - module_put(device->dev->driver->owner); - - vfio_device_unassign_container(device); + vfio_device_group_close(device); vfio_device_put_registration(device); @@ -1568,7 +1000,7 @@ static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma) return device->ops->mmap(device, vma); } -static const struct file_operations vfio_device_fops = { +const struct file_operations vfio_device_fops = { .owner = THIS_MODULE, .release = vfio_device_fops_release, .read = vfio_device_fops_read, @@ -1578,118 +1010,6 @@ static const struct file_operations vfio_device_fops = { .mmap = vfio_device_fops_mmap, }; -/** - * 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; - bool ret; - - if (!vfio_file_is_group(file)) - return true; - - mutex_lock(&group->group_lock); - if (group->container) { - ret = vfio_container_ioctl_check_extension(group->container, - VFIO_DMA_CC_IOMMU); - } else { - /* - * Since the coherency state is determined only once a container - * is attached the user must do so before they can prove they - * have permission. - */ - ret = true; - } - mutex_unlock(&group->group_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); - /* * Sub-module support */ @@ -1810,35 +1130,136 @@ int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs, EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare); /* - * Module/class support + * Pin contiguous user pages and return their associated host pages for local + * domain only. + * @device [in] : device + * @iova [in] : starting IOVA of user pages to be pinned. + * @npage [in] : count of pages to be pinned. This count should not + * be greater than VFIO_PIN_PAGES_MAX_ENTRIES. + * @prot [in] : protection flags + * @pages[out] : array of host pages + * Return error or number of pages pinned. + * + * A driver may only call this function if the vfio_device was created + * by vfio_register_emulated_iommu_dev() due to vfio_device_container_pin_pages(). + */ +int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova, + int npage, int prot, struct page **pages) +{ + /* group->container cannot change while a vfio device is open */ + if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device))) + return -EINVAL; + if (vfio_device_has_container(device)) + return vfio_device_container_pin_pages(device, iova, + npage, prot, pages); + if (device->iommufd_access) { + int ret; + + if (iova > ULONG_MAX) + return -EINVAL; + /* + * VFIO ignores the sub page offset, npages is from the start of + * a PAGE_SIZE chunk of IOVA. The caller is expected to recover + * the sub page offset by doing: + * pages[0] + (iova % PAGE_SIZE) + */ + ret = iommufd_access_pin_pages( + device->iommufd_access, ALIGN_DOWN(iova, PAGE_SIZE), + npage * PAGE_SIZE, pages, + (prot & IOMMU_WRITE) ? IOMMUFD_ACCESS_RW_WRITE : 0); + if (ret) + return ret; + return npage; + } + return -EINVAL; +} +EXPORT_SYMBOL(vfio_pin_pages); + +/* + * Unpin contiguous host pages for local domain only. + * @device [in] : device + * @iova [in] : starting address of user pages to be unpinned. + * @npage [in] : count of pages to be unpinned. This count should not + * be greater than VFIO_PIN_PAGES_MAX_ENTRIES. + */ +void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage) +{ + if (WARN_ON(!vfio_assert_device_open(device))) + return; + + if (vfio_device_has_container(device)) { + vfio_device_container_unpin_pages(device, iova, npage); + return; + } + if (device->iommufd_access) { + if (WARN_ON(iova > ULONG_MAX)) + return; + iommufd_access_unpin_pages(device->iommufd_access, + ALIGN_DOWN(iova, PAGE_SIZE), + npage * PAGE_SIZE); + return; + } +} +EXPORT_SYMBOL(vfio_unpin_pages); + +/* + * This interface allows the CPUs to perform some sort of virtual DMA on + * behalf of the device. + * + * CPUs read/write from/into a range of IOVAs pointing to user space memory + * into/from a kernel buffer. + * + * As the read/write of user space memory is conducted via the CPUs and is + * not a real device DMA, it is not necessary to pin the user space memory. + * + * @device [in] : VFIO device + * @iova [in] : base IOVA of a user space buffer + * @data [in] : pointer to kernel buffer + * @len [in] : kernel buffer length + * @write : indicate read or write + * Return error code on failure or 0 on success. */ -static char *vfio_devnode(struct device *dev, umode_t *mode) +int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data, + size_t len, bool write) { - return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev)); + if (!data || len <= 0 || !vfio_assert_device_open(device)) + return -EINVAL; + + if (vfio_device_has_container(device)) + return vfio_device_container_dma_rw(device, iova, + data, len, write); + + if (device->iommufd_access) { + unsigned int flags = 0; + + if (iova > ULONG_MAX) + return -EINVAL; + + /* VFIO historically tries to auto-detect a kthread */ + if (!current->mm) + flags |= IOMMUFD_ACCESS_RW_KTHREAD; + if (write) + flags |= IOMMUFD_ACCESS_RW_WRITE; + return iommufd_access_rw(device->iommufd_access, iova, data, + len, flags); + } + return -EINVAL; } +EXPORT_SYMBOL(vfio_dma_rw); +/* + * Module/class support + */ static int __init vfio_init(void) { int ret; - ida_init(&vfio.group_ida); ida_init(&vfio.device_ida); - mutex_init(&vfio.group_lock); - INIT_LIST_HEAD(&vfio.group_list); - ret = vfio_container_init(); + ret = vfio_group_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; - /* /sys/class/vfio-dev/vfioX */ vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); if (IS_ERR(vfio.device_class)) { @@ -1846,36 +1267,20 @@ static int __init vfio_init(void) goto err_dev_class; } - ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); - if (ret) - goto err_alloc_chrdev; - pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); return 0; -err_alloc_chrdev: - class_destroy(vfio.device_class); - vfio.device_class = NULL; err_dev_class: - class_destroy(vfio.class); - vfio.class = NULL; -err_group_class: - vfio_container_cleanup(); + vfio_group_cleanup(); return ret; } static void __exit vfio_cleanup(void) { - WARN_ON(!list_empty(&vfio.group_list)); - ida_destroy(&vfio.device_ida); - ida_destroy(&vfio.group_ida); - unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); class_destroy(vfio.device_class); vfio.device_class = NULL; - class_destroy(vfio.class); - vfio_container_cleanup(); - vfio.class = NULL; + vfio_group_cleanup(); xa_destroy(&vfio_device_set_xa); } @@ -1886,6 +1291,4 @@ MODULE_VERSION(DRIVER_VERSION); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); -MODULE_ALIAS_MISCDEV(VFIO_MINOR); -MODULE_ALIAS("devname:vfio/vfio"); MODULE_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce"); |