diff options
| -rw-r--r-- | MAINTAINERS | 7 | ||||
| -rw-r--r-- | drivers/iommu/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/iommu/Makefile | 1 | ||||
| -rw-r--r-- | drivers/iommu/virtio-iommu.c | 916 | ||||
| -rw-r--r-- | include/uapi/linux/virtio_ids.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/virtio_iommu.h | 106 |
6 files changed, 1042 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 429c6c624861..62bd1834d95a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -16807,6 +16807,13 @@ S: Maintained F: drivers/virtio/virtio_input.c F: include/uapi/linux/virtio_input.h +VIRTIO IOMMU DRIVER +M: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> +L: virtualization@lists.linux-foundation.org +S: Maintained +F: drivers/iommu/virtio-iommu.c +F: include/uapi/linux/virtio_iommu.h + VIRTUAL BOX GUEST DEVICE DRIVER M: Hans de Goede <hdegoede@redhat.com> M: Arnd Bergmann <arnd@arndb.de> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 83664db5221d..e15cdcd8cb3c 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -473,4 +473,15 @@ config HYPERV_IOMMU Stub IOMMU driver to handle IRQs as to allow Hyper-V Linux guests to run with x2APIC mode enabled. +config VIRTIO_IOMMU + bool "Virtio IOMMU driver" + depends on VIRTIO=y + depends on ARM64 + select IOMMU_API + select INTERVAL_TREE + help + Para-virtualised IOMMU driver with virtio. + + Say Y here if you intend to run this kernel as a guest. + endif # IOMMU_SUPPORT diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 8c71a15e986b..f13f36ae1af6 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -33,3 +33,4 @@ obj-$(CONFIG_FSL_PAMU) += fsl_pamu.o fsl_pamu_domain.o obj-$(CONFIG_S390_IOMMU) += s390-iommu.o obj-$(CONFIG_QCOM_IOMMU) += qcom_iommu.o obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o +obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c new file mode 100644 index 000000000000..6fa012cd727e --- /dev/null +++ b/drivers/iommu/virtio-iommu.c @@ -0,0 +1,916 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Virtio driver for the paravirtualized IOMMU + * + * Copyright (C) 2018 Arm Limited + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/amba/bus.h> +#include <linux/delay.h> +#include <linux/dma-iommu.h> +#include <linux/freezer.h> +#include <linux/interval_tree.h> +#include <linux/iommu.h> +#include <linux/module.h> +#include <linux/of_iommu.h> +#include <linux/of_platform.h> +#include <linux/pci.h> +#include <linux/platform_device.h> +#include <linux/virtio.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ids.h> +#include <linux/wait.h> + +#include <uapi/linux/virtio_iommu.h> + +#define MSI_IOVA_BASE 0x8000000 +#define MSI_IOVA_LENGTH 0x100000 + +#define VIOMMU_REQUEST_VQ 0 +#define VIOMMU_NR_VQS 1 + +struct viommu_dev { + struct iommu_device iommu; + struct device *dev; + struct virtio_device *vdev; + + struct ida domain_ids; + + struct virtqueue *vqs[VIOMMU_NR_VQS]; + spinlock_t request_lock; + struct list_head requests; + + /* Device configuration */ + struct iommu_domain_geometry geometry; + u64 pgsize_bitmap; + u8 domain_bits; +}; + +struct viommu_mapping { + phys_addr_t paddr; + struct interval_tree_node iova; + u32 flags; +}; + +struct viommu_domain { + struct iommu_domain domain; + struct viommu_dev *viommu; + struct mutex mutex; /* protects viommu pointer */ + unsigned int id; + + spinlock_t mappings_lock; + struct rb_root_cached mappings; + + unsigned long nr_endpoints; +}; + +struct viommu_endpoint { + struct viommu_dev *viommu; + struct viommu_domain *vdomain; +}; + +struct viommu_request { + struct list_head list; + void *writeback; + unsigned int write_offset; + unsigned int len; + char buf[]; +}; + +#define to_viommu_domain(domain) \ + container_of(domain, struct viommu_domain, domain) + +static int viommu_get_req_errno(void *buf, size_t len) +{ + struct virtio_iommu_req_tail *tail = buf + len - sizeof(*tail); + + switch (tail->status) { + case VIRTIO_IOMMU_S_OK: + return 0; + case VIRTIO_IOMMU_S_UNSUPP: + return -ENOSYS; + case VIRTIO_IOMMU_S_INVAL: + return -EINVAL; + case VIRTIO_IOMMU_S_RANGE: + return -ERANGE; + case VIRTIO_IOMMU_S_NOENT: + return -ENOENT; + case VIRTIO_IOMMU_S_FAULT: + return -EFAULT; + case VIRTIO_IOMMU_S_IOERR: + case VIRTIO_IOMMU_S_DEVERR: + default: + return -EIO; + } +} + +static void viommu_set_req_status(void *buf, size_t len, int status) +{ + struct virtio_iommu_req_tail *tail = buf + len - sizeof(*tail); + + tail->status = status; +} + +static off_t viommu_get_write_desc_offset(struct viommu_dev *viommu, + struct virtio_iommu_req_head *req, + size_t len) +{ + size_t tail_size = sizeof(struct virtio_iommu_req_tail); + + return len - tail_size; +} + +/* + * __viommu_sync_req - Complete all in-flight requests + * + * Wait for all added requests to complete. When this function returns, all + * requests that were in-flight at the time of the call have completed. + */ +static int __viommu_sync_req(struct viommu_dev *viommu) +{ + int ret = 0; + unsigned int len; + size_t write_len; + struct viommu_request *req; + struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; + + assert_spin_locked(&viommu->request_lock); + + virtqueue_kick(vq); + + while (!list_empty(&viommu->requests)) { + len = 0; + req = virtqueue_get_buf(vq, &len); + if (!req) + continue; + + if (!len) + viommu_set_req_status(req->buf, req->len, + VIRTIO_IOMMU_S_IOERR); + + write_len = req->len - req->write_offset; + if (req->writeback && len == write_len) + memcpy(req->writeback, req->buf + req->write_offset, + write_len); + + list_del(&req->list); + kfree(req); + } + + return ret; +} + +static int viommu_sync_req(struct viommu_dev *viommu) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(&viommu->request_lock, flags); + ret = __viommu_sync_req(viommu); + if (ret) + dev_dbg(viommu->dev, "could not sync requests (%d)\n", ret); + spin_unlock_irqrestore(&viommu->request_lock, flags); + + return ret; +} + +/* + * __viommu_add_request - Add one request to the queue + * @buf: pointer to the request buffer + * @len: length of the request buffer + * @writeback: copy data back to the buffer when the request completes. + * + * Add a request to the queue. Only synchronize the queue if it's already full. + * Otherwise don't kick the queue nor wait for requests to complete. + * + * When @writeback is true, data written by the device, including the request + * status, is copied into @buf after the request completes. This is unsafe if + * the caller allocates @buf on stack and drops the lock between add_req() and + * sync_req(). + * + * Return 0 if the request was successfully added to the queue. + */ +static int __viommu_add_req(struct viommu_dev *viommu, void *buf, size_t len, + bool writeback) +{ + int ret; + off_t write_offset; + struct viommu_request *req; + struct scatterlist top_sg, bottom_sg; + struct scatterlist *sg[2] = { &top_sg, &bottom_sg }; + struct virtqueue *vq = viommu->vqs[VIOMMU_REQUEST_VQ]; + + assert_spin_locked(&viommu->request_lock); + + write_offset = viommu_get_write_desc_offset(viommu, buf, len); + if (write_offset <= 0) + return -EINVAL; + + req = kzalloc(sizeof(*req) + len, GFP_ATOMIC); + if (!req) + return -ENOMEM; + + req->len = len; + if (writeback) { + req->writeback = buf + write_offset; + req->write_offset = write_offset; + } + memcpy(&req->buf, buf, write_offset); + + sg_init_one(&top_sg, req->buf, write_offset); + sg_init_one(&bottom_sg, req->buf + write_offset, len - write_offset); + + ret = virtqueue_add_sgs(vq, sg, 1, 1, req, GFP_ATOMIC); + if (ret == -ENOSPC) { + /* If the queue is full, sync and retry */ + if (!__viommu_sync_req(viommu)) + ret = virtqueue_add_sgs(vq, sg, 1, 1, req, GFP_ATOMIC); + } + if (ret) + goto err_free; + + list_add_tail(&req->list, &viommu->requests); + return 0; + +err_free: + kfree(req); + return ret; +} + +static int viommu_add_req(struct viommu_dev *viommu, void *buf, size_t len) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(&viommu->request_lock, flags); + ret = __viommu_add_req(viommu, buf, len, false); + if (ret) + dev_dbg(viommu->dev, "could not add request: %d\n", ret); + spin_unlock_irqrestore(&viommu->request_lock, flags); + + return ret; +} + +/* + * Send a request and wait for it to complete. Return the request status (as an + * errno) + */ +static int viommu_send_req_sync(struct viommu_dev *viommu, void *buf, + size_t len) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(&viommu->request_lock, flags); + + ret = __viommu_add_req(viommu, buf, len, true); + if (ret) { + dev_dbg(viommu->dev, "could not add request (%d)\n", ret); + goto out_unlock; + } + + ret = __viommu_sync_req(viommu); + if (ret) { + dev_dbg(viommu->dev, "could not sync requests (%d)\n", ret); + /* Fall-through (get the actual request status) */ + } + + ret = viommu_get_req_errno(buf, len); +out_unlock: + spin_unlock_irqrestore(&viommu->request_lock, flags); + return ret; +} + +/* + * viommu_add_mapping - add a mapping to the internal tree + * + * On success, return the new mapping. Otherwise return NULL. + */ +static int viommu_add_mapping(struct viommu_domain *vdomain, unsigned long iova, + phys_addr_t paddr, size_t size, u32 flags) +{ + unsigned long irqflags; + struct viommu_mapping *mapping; + + mapping = kzalloc(sizeof(*mapping), GFP_ATOMIC); + if (!mapping) + return -ENOMEM; + + mapping->paddr = paddr; + mapping->iova.start = iova; + mapping->iova.last = iova + size - 1; + mapping->flags = flags; + + spin_lock_irqsave(&vdomain->mappings_lock, irqflags); + interval_tree_insert(&mapping->iova, &vdomain->mappings); + spin_unlock_irqrestore(&vdomain->mappings_lock, irqflags); + + return 0; +} + +/* + * viommu_del_mappings - remove mappings from the internal tree + * + * @vdomain: the domain + * @iova: start of the range + * @size: size of the range. A size of 0 corresponds to the entire address + * space. + * + * On success, returns the number of unmapped bytes (>= size) + */ +static size_t viommu_del_mappings(struct viommu_domain *vdomain, + unsigned long iova, size_t size) +{ + size_t unmapped = 0; + unsigned long flags; + unsigned long last = iova + size - 1; + struct viommu_mapping *mapping = NULL; + struct interval_tree_node *node, *next; + + spin_lock_irqsave(&vdomain->mappings_lock, flags); + next = interval_tree_iter_first(&vdomain->mappings, iova, last); + while (next) { + node = next; + mapping = container_of(node, struct viommu_mapping, iova); + next = interval_tree_iter_next(node, iova, last); + + /* Trying to split a mapping? */ + if (mapping->iova.start < iova) + break; + + /* + * Virtio-iommu doesn't allow UNMAP to split a mapping created + * with a single MAP request, so remove the full mapping. + */ + unmapped += mapping->iova.last - mapping->iova.start + 1; + + interval_tree_remove(node, &vdomain->mappings); + kfree(mapping); + } + spin_unlock_irqrestore(&vdomain->mappings_lock, flags); + + return unmapped; +} + +/* + * viommu_replay_mappings - re-send MAP requests + * + * When reattaching a domain that was previously detached from all endpoints, + * mappings were deleted from the device. Re-create the mappings available in + * the internal tree. + */ +static int viommu_replay_mappings(struct viommu_domain *vdomain) +{ + int ret = 0; + unsigned long flags; + struct viommu_mapping *mapping; + struct interval_tree_node *node; + struct virtio_iommu_req_map map; + + spin_lock_irqsave(&vdomain->mappings_lock, flags); + node = interval_tree_iter_first(&vdomain->mappings, 0, -1UL); + while (node) { + mapping = container_of(node, struct viommu_mapping, iova); + map = (struct virtio_iommu_req_map) { + .head.type = VIRTIO_IOMMU_T_MAP, + .domain = cpu_to_le32(vdomain->id), + .virt_start = cpu_to_le64(mapping->iova.start), + .virt_end = cpu_to_le64(mapping->iova.last), + .phys_start = cpu_to_le64(mapping->paddr), + .flags = cpu_to_le32(mapping->flags), + }; + + ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map)); + if (ret) + break; + + node = interval_tree_iter_next(node, 0, -1UL); + } + spin_unlock_irqrestore(&vdomain->mappings_lock, flags); + + return ret; +} + +/* IOMMU API */ + +static struct iommu_domain *viommu_domain_alloc(unsigned type) +{ + struct viommu_domain *vdomain; + + if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA) + return NULL; + + vdomain = kzalloc(sizeof(*vdomain), GFP_KERNEL); + if (!vdomain) + return NULL; + + mutex_init(&vdomain->mutex); + spin_lock_init(&vdomain->mappings_lock); + vdomain->mappings = RB_ROOT_CACHED; + + if (type == IOMMU_DOMAIN_DMA && + iommu_get_dma_cookie(&vdomain->domain)) { + kfree(vdomain); + return NULL; + } + + return &vdomain->domain; +} + +static int viommu_domain_finalise(struct viommu_dev *viommu, + struct iommu_domain *domain) +{ + int ret; + struct viommu_domain *vdomain = to_viommu_domain(domain); + unsigned int max_domain = viommu->domain_bits > 31 ? ~0 : + (1U << viommu->domain_bits) - 1; + + vdomain->viommu = viommu; + + domain->pgsize_bitmap = viommu->pgsize_bitmap; + domain->geometry = viommu->geometry; + + ret = ida_alloc_max(&viommu->domain_ids, max_domain, GFP_KERNEL); + if (ret >= 0) + vdomain->id = (unsigned int)ret; + + return ret > 0 ? 0 : ret; +} + +static void viommu_domain_free(struct iommu_domain *domain) +{ + struct viommu_domain *vdomain = to_viommu_domain(domain); + + iommu_put_dma_cookie(domain); + + /* Free all remaining mappings (size 2^64) */ + viommu_del_mappings(vdomain, 0, 0); + + if (vdomain->viommu) + ida_free(&vdomain->viommu->domain_ids, vdomain->id); + + kfree(vdomain); +} + +static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) +{ + int i; + int ret = 0; + struct virtio_iommu_req_attach req; + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + struct viommu_endpoint *vdev = fwspec->iommu_priv; + struct viommu_domain *vdomain = to_viommu_domain(domain); + + mutex_lock(&vdomain->mutex); + if (!vdomain->viommu) { + /* + * Properly initialize the domain now that we know which viommu + * owns it. + */ + ret = viommu_domain_finalise(vdev->viommu, domain); + } else if (vdomain->viommu != vdev->viommu) { + dev_err(dev, "cannot attach to foreign vIOMMU\n"); + ret = -EXDEV; + } + mutex_unlock(&vdomain->mutex); + + if (ret) + return ret; + + /* + * In the virtio-iommu device, when attaching the endpoint to a new + * domain, it is detached from the old one and, if as as a result the + * old domain isn't attached to any endpoint, all mappings are removed + * from the old domain and it is freed. + * + * In the driver the old domain still exists, and its mappings will be + * recreated if it gets reattached to an endpoint. Otherwise it will be + * freed explicitly. + * + * vdev->vdomain is protected by group->mutex + */ + if (vdev->vdomain) + vdev->vdomain->nr_endpoints--; + + req = (struct virtio_iommu_req_attach) { + .head.type = VIRTIO_IOMMU_T_ATTACH, + .domain = cpu_to_le32(vdomain->id), + }; + + for (i = 0; i < fwspec->num_ids; i++) { + req.endpoint = cpu_to_le32(fwspec->ids[i]); + + ret = viommu_send_req_sync(vdomain->viommu, &req, sizeof(req)); + if (ret) + return ret; + } + + if (!vdomain->nr_endpoints) { + /* + * This endpoint is the first to be attached to the domain. + * Replay existing mappings (e.g. SW MSI). + */ + ret = viommu_replay_mappings(vdomain); + if (ret) + return ret; + } + + vdomain->nr_endpoints++; + vdev->vdomain = vdomain; + + return 0; +} + +static int viommu_map(struct iommu_domain *domain, unsigned long iova, + phys_addr_t paddr, size_t size, int prot) +{ + int ret; + int flags; + struct virtio_iommu_req_map map; + struct viommu_domain *vdomain = to_viommu_domain(domain); + + flags = (prot & IOMMU_READ ? VIRTIO_IOMMU_MAP_F_READ : 0) | + (prot & IOMMU_WRITE ? VIRTIO_IOMMU_MAP_F_WRITE : 0) | + (prot & IOMMU_MMIO ? VIRTIO_IOMMU_MAP_F_MMIO : 0); + + ret = viommu_add_mapping(vdomain, iova, paddr, size, flags); + if (ret) + return ret; + + map = (struct virtio_iommu_req_map) { + .head.type = VIRTIO_IOMMU_T_MAP, + .domain = cpu_to_le32(vdomain->id), + .virt_start = cpu_to_le64(iova), + .phys_start = cpu_to_le64(paddr), + .virt_end = cpu_to_le64(iova + size - 1), + .flags = cpu_to_le32(flags), + }; + + if (!vdomain->nr_endpoints) + return 0; + + ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map)); + if (ret) + viommu_del_mappings(vdomain, iova, size); + + return ret; +} + +static size_t viommu_unmap(struct iommu_domain *domain, unsigned long iova, + size_t size) +{ + int ret = 0; + size_t unmapped; + struct virtio_iommu_req_unmap unmap; + struct viommu_domain *vdomain = to_viommu_domain(domain); + + unmapped = viommu_del_mappings(vdomain, iova, size); + if (unmapped < size) + return 0; + + /* Device already removed all mappings after detach. */ + if (!vdomain->nr_endpoints) + return unmapped; + + unmap = (struct virtio_iommu_req_unmap) { + .head.type = VIRTIO_IOMMU_T_UNMAP, + .domain = cpu_to_le32(vdomain->id), + .virt_start = cpu_to_le64(iova), + .virt_end = cpu_to_le64(iova + unmapped - 1), + }; + + ret = viommu_add_req(vdomain->viommu, &unmap, sizeof(unmap)); + return ret ? 0 : unmapped; +} + +static phys_addr_t viommu_iova_to_phys(struct iommu_domain *domain, + dma_addr_t iova) +{ + u64 paddr = 0; + unsigned long flags; + struct viommu_mapping *mapping; + struct interval_tree_node *node; + struct viommu_domain *vdomain = to_viommu_domain(domain); + + spin_lock_irqsave(&vdomain->mappings_lock, flags); + node = interval_tree_iter_first(&vdomain->mappings, iova, iova); + if (node) { + mapping = container_of(node, struct viommu_mapping, iova); + paddr = mapping->paddr + (iova - mapping->iova.start); + } + spin_unlock_irqrestore(&vdomain->mappings_lock, flags); + + return paddr; +} + +static void viommu_iotlb_sync(struct iommu_domain *domain) +{ + struct viommu_domain *vdomain = to_viommu_domain(domain); + + viommu_sync_req(vdomain->viommu); +} + +static void viommu_get_resv_regions(struct device *dev, struct list_head *head) +{ + struct iommu_resv_region *region; + int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; + + region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH, prot, + IOMMU_RESV_SW_MSI); + if (!region) + return; + + list_add_tail(®ion->list, head); + iommu_dma_get_resv_regions(dev, head); +} + +static void viommu_put_resv_regions(struct device *dev, struct list_head *head) +{ + struct iommu_resv_region *entry, *next; + + list_for_each_entry_safe(entry, next, head, list) + kfree(entry); +} + +static struct iommu_ops viommu_ops; +static struct virtio_driver virtio_iommu_drv; + +static int viommu_match_node(struct device *dev, void *data) +{ + return dev->parent->fwnode == data; +} + +static struct viommu_dev *viommu_get_by_fwnode(struct fwnode_handle *fwnode) +{ + struct device *dev = driver_find_device(&virtio_iommu_drv.driver, NULL, + fwnode, viommu_match_node); + put_device(dev); + + return dev ? dev_to_virtio(dev)->priv : NULL; +} + +static int viommu_add_device(struct device *dev) +{ + int ret; + struct iommu_group *group; + struct viommu_endpoint *vdev; + struct viommu_dev *viommu = NULL; + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + + if (!fwspec || fwspec->ops != &viommu_ops) + return -ENODEV; + + viommu = viommu_get_by_fwnode(fwspec->iommu_fwnode); + if (!viommu) + return -ENODEV; + + vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); + if (!vdev) + return -ENOMEM; + + vdev->viommu = viommu; + fwspec->iommu_priv = vdev; + + ret = iommu_device_link(&viommu->iommu, dev); + if (ret) + goto err_free_dev; + + /* + * Last step creates a default domain and attaches to it. Everything + * must be ready. + */ + group = iommu_group_get_for_dev(dev); + if (IS_ERR(group)) { + ret = PTR_ERR(group); + goto err_unlink_dev; + } + + iommu_group_put(group); + + return PTR_ERR_OR_ZERO(group); + +err_unlink_dev: + iommu_device_unlink(&viommu->iommu, dev); +err_free_dev: + kfree(vdev); + + return ret; +} + +static void viommu_remove_device(struct device *dev) +{ + struct viommu_endpoint *vdev; + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + + if (!fwspec || fwspec->ops != &viommu_ops) + return; + + vdev = fwspec->iommu_priv; + + iommu_group_remove_device(dev); + iommu_device_unlink(&vdev->viommu->iommu, dev); + kfree(vdev); +} + +static struct iommu_group *viommu_device_group(struct device *dev) +{ + if (dev_is_pci(dev)) + return pci_device_group(dev); + else + return generic_device_group(dev); +} + +static int viommu_of_xlate(struct device *dev, struct of_phandle_args *args) +{ + return iommu_fwspec_add_ids(dev, args->args, 1); +} + +static struct iommu_ops viommu_ops = { + .domain_alloc = viommu_domain_alloc, + .domain_free = viommu_domain_free, + .attach_dev = viommu_attach_dev, + .map = viommu_map, + .unmap = viommu_unmap, + .iova_to_phys = viommu_iova_to_phys, + .iotlb_sync = viommu_iotlb_sync, + .add_device = viommu_add_device, + .remove_device = viommu_remove_device, + .device_group = viommu_device_group, + .get_resv_regions = viommu_get_resv_regions, + .put_resv_regions = viommu_put_resv_regions, + .of_xlate = viommu_of_xlate, +}; + +static int viommu_init_vqs(struct viommu_dev *viommu) +{ + struct virtio_device *vdev = dev_to_virtio(viommu->dev); + const char *name = "request"; + void *ret; + + ret = virtio_find_single_vq(vdev, NULL, name); + if (IS_ERR(ret)) { + dev_err(viommu->dev, "cannot find VQ\n"); + return PTR_ERR(ret); + } + + viommu->vqs[VIOMMU_REQUEST_VQ] = ret; + + return 0; +} + +static int viommu_probe(struct virtio_device *vdev) +{ + struct device *parent_dev = vdev->dev.parent; + struct viommu_dev *viommu = NULL; + struct device *dev = &vdev->dev; + u64 input_start = 0; + u64 input_end = -1UL; + int ret; + + if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1) || + !virtio_has_feature(vdev, VIRTIO_IOMMU_F_MAP_UNMAP)) + return -ENODEV; + + viommu = devm_kzalloc(dev, sizeof(*viommu), GFP_KERNEL); + if (!viommu) + return -ENOMEM; + + spin_lock_init(&viommu->request_lock); + ida_init(&viommu->domain_ids); + viommu->dev = dev; + viommu->vdev = vdev; + INIT_LIST_HEAD(&viommu->requests); + + ret = viommu_init_vqs(viommu); + if (ret) + return ret; + + virtio_cread(vdev, struct virtio_iommu_config, page_size_mask, + &viommu->pgsize_bitmap); + + if (!viommu->pgsize_bitmap) { + ret = -EINVAL; + goto err_free_vqs; + } + + viommu->domain_bits = 32; + + /* Optional features */ + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, + struct virtio_iommu_config, input_range.start, + &input_start); + + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_INPUT_RANGE, + struct virtio_iommu_config, input_range.end, + &input_end); + + virtio_cread_feature(vdev, VIRTIO_IOMMU_F_DOMAIN_BITS, + struct virtio_iommu_config, domain_bits, + &viommu->domain_bits); + + viommu->geometry = (struct iommu_domain_geometry) { + .aperture_start = input_start, + .aperture_end = input_end, + .force_aperture = true, + }; + + viommu_ops.pgsize_bitmap = viommu->pgsize_bitmap; + + virtio_device_ready(vdev); + + ret = iommu_device_sysfs_add(&viommu->iommu, dev, NULL, "%s", + virtio_bus_name(vdev)); + if (ret) + goto err_free_vqs; + + iommu_device_set_ops(&viommu->iommu, &viommu_ops); + iommu_device_set_fwnode(&viommu->iommu, parent_dev->fwnode); + + iommu_device_register(&viommu->iommu); + +#ifdef CONFIG_PCI + if (pci_bus_type.iommu_ops != &viommu_ops) { + pci_request_acs(); + ret = bus_set_iommu(&pci_bus_type, &viommu_ops); + if (ret) + goto err_unregister; + } +#endif +#ifdef CONFIG_ARM_AMBA + if (amba_bustype.iommu_ops != &viommu_ops) { + ret = bus_set_iommu(&amba_bustype, &viommu_ops); + if (ret) + goto err_unregister; + } +#endif + if (platform_bus_type.iommu_ops != &viommu_ops) { + ret = bus_set_iommu(&platform_bus_type, &viommu_ops); + if (ret) + goto err_unregister; + } + + vdev->priv = viommu; + + dev_info(dev, "input address: %u bits\n", + order_base_2(viommu->geometry.aperture_end)); + dev_info(dev, "page mask: %#llx\n", viommu->pgsize_bitmap); + + return 0; + +err_unregister: + iommu_device_sysfs_remove(&viommu->iommu); + iommu_device_unregister(&viommu->iommu); +err_free_vqs: + vdev->config->del_vqs(vdev); + + return ret; +} + +static void viommu_remove(struct virtio_device *vdev) +{ + struct viommu_dev *viommu = vdev->priv; + + iommu_device_sysfs_remove(&viommu->iommu); + iommu_device_unregister(&viommu->iommu); + + /* Stop all virtqueues */ + vdev->config->reset(vdev); + vdev->config->del_vqs(vdev); + + dev_info(&vdev->dev, "device removed\n"); +} + +static void viommu_config_changed(struct virtio_device *vdev) +{ + dev_warn(&vdev->dev, "config changed\n"); +} + +static unsigned int features[] = { + VIRTIO_IOMMU_F_MAP_UNMAP, + VIRTIO_IOMMU_F_DOMAIN_BITS, + VIRTIO_IOMMU_F_INPUT_RANGE, +}; + +static struct virtio_device_id id_table[] = { + { VIRTIO_ID_IOMMU, VIRTIO_DEV_ANY_ID }, + { 0 }, +}; + +static struct virtio_driver virtio_iommu_drv = { + .driver.name = KBUILD_MODNAME, + .driver.owner = THIS_MODULE, + .id_table = id_table, + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), + .probe = viommu_probe, + .remove = viommu_remove, + .config_changed = viommu_config_changed, +}; + +module_virtio_driver(virtio_iommu_drv); + +MODULE_DESCRIPTION("Virtio IOMMU driver"); +MODULE_AUTHOR("Jean-Philippe Brucker <jean-philippe.brucker@arm.com>"); +MODULE_LICENSE("GPL v2"); diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h index 6d5c3b2d4f4d..cfe47c5d9a56 100644 --- a/include/uapi/linux/virtio_ids.h +++ b/include/uapi/linux/virtio_ids.h @@ -43,5 +43,6 @@ #define VIRTIO_ID_INPUT 18 /* virtio input */ #define VIRTIO_ID_VSOCK 19 /* virtio vsock transport */ #define VIRTIO_ID_CRYPTO 20 /* virtio crypto */ +#define VIRTIO_ID_IOMMU 23 /* virtio IOMMU */ #endif /* _LINUX_VIRTIO_IDS_H */ diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h new file mode 100644 index 000000000000..5e5fd62689fb --- /dev/null +++ b/include/uapi/linux/virtio_iommu.h @@ -0,0 +1,106 @@ +/* SPDX-License-Identifier: BSD-3-Clause */ +/* + * Virtio-iommu definition v0.9 + * + * Copyright (C) 2018 Arm Ltd. + */ +#ifndef _UAPI_LINUX_VIRTIO_IOMMU_H +#define _UAPI_LINUX_VIRTIO_IOMMU_H + +#include <linux/types.h> + +/* Feature bits */ +#define VIRTIO_IOMMU_F_INPUT_RANGE 0 +#define VIRTIO_IOMMU_F_DOMAIN_BITS 1 +#define VIRTIO_IOMMU_F_MAP_UNMAP 2 +#define VIRTIO_IOMMU_F_BYPASS 3 + +struct virtio_iommu_range { + __u64 start; + __u64 end; +}; + +struct virtio_iommu_config { + /* Supported page sizes */ + __u64 page_size_mask; + /* Supported IOVA range */ + struct virtio_iommu_range input_range; + /* Max domain ID size */ + __u8 domain_bits; + __u8 padding[3]; + /* Probe buffer size */ + __u32 probe_size; +}; + +/* Request types */ +#define VIRTIO_IOMMU_T_ATTACH 0x01 +#define VIRTIO_IOMMU_T_DETACH 0x02 +#define VIRTIO_IOMMU_T_MAP 0x03 +#define VIRTIO_IOMMU_T_UNMAP 0x04 + +/* Status types */ +#define VIRTIO_IOMMU_S_OK 0x00 +#define VIRTIO_IOMMU_S_IOERR 0x01 +#define VIRTIO_IOMMU_S_UNSUPP 0x02 +#define VIRTIO_IOMMU_S_DEVERR 0x03 +#define VIRTIO_IOMMU_S_INVAL 0x04 +#define VIRTIO_IOMMU_S_RANGE 0x05 +#define VIRTIO_IOMMU_S_NOENT 0x06 +#define VIRTIO_IOMMU_S_FAULT 0x07 + +struct virtio_iommu_req_head { + __u8 type; + __u8 reserved[3]; +}; + +struct virtio_iommu_req_tail { + __u8 status; + __u8 reserved[3]; +}; + +struct virtio_iommu_req_attach { + struct virtio_iommu_req_head head; + __le32 domain; + __le32 endpoint; + __u8 reserved[8]; + struct virtio_iommu_req_tail tail; +}; + +struct virtio_iommu_req_detach { + struct virtio_iommu_req_head head; + __le32 domain; + __le32 endpoint; + __u8 reserved[8]; + struct virtio_iommu_req_tail tail; +}; + +#define VIRTIO_IOMMU_MAP_F_READ (1 << 0) +#define VIRTIO_IOMMU_MAP_F_WRITE (1 << 1) +#define VIRTIO_IOMMU_MAP_F_EXEC (1 << 2) +#define VIRTIO_IOMMU_MAP_F_MMIO (1 << 3) + +#define VIRTIO_IOMMU_MAP_F_MASK (VIRTIO_IOMMU_MAP_F_READ | \ + VIRTIO_IOMMU_MAP_F_WRITE | \ + VIRTIO_IOMMU_MAP_F_EXEC | \ + VIRTIO_IOMMU_MAP_F_MMIO) + +struct virtio_iommu_req_map { + struct virtio_iommu_req_head head; + __le32 domain; + __le64 virt_start; + __le64 virt_end; + __le64 phys_start; + __le32 flags; + struct virtio_iommu_req_tail tail; +}; + +struct virtio_iommu_req_unmap { + struct virtio_iommu_req_head head; + __le32 domain; + __le64 virt_start; + __le64 virt_end; + __u8 reserved[4]; + struct virtio_iommu_req_tail tail; +}; + +#endif |