--- /dev/null
+/*
+ * VFIO: IOMMU DMA mapping support for Type1 IOMMU
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
+ * Author: Alex Williamson <alex.williamson@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Derived from original vfio:
+ * Copyright 2010 Cisco Systems, Inc. All rights reserved.
+ * Author: Tom Lyon, pugs@cisco.com
+ *
+ * We arbitrarily define a Type1 IOMMU as one matching the below code.
+ * It could be called the x86 IOMMU as it's designed for AMD-Vi & Intel
+ * VT-d, but that makes it harder to re-use as theoretically anyone
+ * implementing a similar IOMMU could make use of this. We expect the
+ * IOMMU to support the IOMMU API and have few to no restrictions around
+ * the IOVA range that can be mapped. The Type1 IOMMU is currently
+ * optimized for relatively static mappings of a userspace process with
+ * userpsace pages pinned into memory. We also assume devices and IOMMU
+ * domains are PCI based as the IOMMU API is still centered around a
+ * device/bus interface rather than a group interface.
+ */
+
+#include <linux/compat.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/rbtree.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/vfio.h>
+#include <linux/workqueue.h>
+
+#define DRIVER_VERSION "0.2"
+#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
+#define DRIVER_DESC "Type1 IOMMU driver for VFIO"
+
+static bool allow_unsafe_interrupts;
+module_param_named(allow_unsafe_interrupts,
+ allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(allow_unsafe_interrupts,
+ "Enable VFIO IOMMU support for on platforms without interrupt remapping support.");
+
+static bool disable_hugepages;
+module_param_named(disable_hugepages,
+ disable_hugepages, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(disable_hugepages,
+ "Disable VFIO IOMMU support for IOMMU hugepages.");
+
+struct vfio_iommu {
+ struct list_head domain_list;
+ struct mutex lock;
+ struct rb_root dma_list;
+ bool v2;
+ bool nesting;
+};
+
+struct vfio_domain {
+ struct iommu_domain *domain;
+ struct list_head next;
+ struct list_head group_list;
+ int prot; /* IOMMU_CACHE */
+ bool fgsp; /* Fine-grained super pages */
+};
+
+struct vfio_dma {
+ struct rb_node node;
+ dma_addr_t iova; /* Device address */
+ unsigned long vaddr; /* Process virtual addr */
+ size_t size; /* Map size (bytes) */
+ int prot; /* IOMMU_READ/WRITE */
+};
+
+struct vfio_group {
+ struct iommu_group *iommu_group;
+ struct list_head next;
+};
+
+/*
+ * This code handles mapping and unmapping of user data buffers
+ * into DMA'ble space using the IOMMU
+ */
+
+static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
+ dma_addr_t start, size_t size)
+{
+ struct rb_node *node = iommu->dma_list.rb_node;
+
+ while (node) {
+ struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
+
+ if (start + size <= dma->iova)
+ node = node->rb_left;
+ else if (start >= dma->iova + dma->size)
+ node = node->rb_right;
+ else
+ return dma;
+ }
+
+ return NULL;
+}
+
+static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
+{
+ struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL;
+ struct vfio_dma *dma;
+
+ while (*link) {
+ parent = *link;
+ dma = rb_entry(parent, struct vfio_dma, node);
+
+ if (new->iova + new->size <= dma->iova)
+ link = &(*link)->rb_left;
+ else
+ link = &(*link)->rb_right;
+ }
+
+ rb_link_node(&new->node, parent, link);
+ rb_insert_color(&new->node, &iommu->dma_list);
+}
+
+static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
+{
+ rb_erase(&old->node, &iommu->dma_list);
+}
+
+struct vwork {
+ struct mm_struct *mm;
+ long npage;
+ struct work_struct work;
+};
+
+/* delayed decrement/increment for locked_vm */
+static void vfio_lock_acct_bg(struct work_struct *work)
+{
+ struct vwork *vwork = container_of(work, struct vwork, work);
+ struct mm_struct *mm;
+
+ mm = vwork->mm;
+ down_write(&mm->mmap_sem);
+ mm->locked_vm += vwork->npage;
+ up_write(&mm->mmap_sem);
+ mmput(mm);
+ kfree(vwork);
+}
+
+static void vfio_lock_acct(long npage)
+{
+ struct vwork *vwork;
+ struct mm_struct *mm;
+
+ if (!current->mm || !npage)
+ return; /* process exited or nothing to do */
+
+ if (down_write_trylock(¤t->mm->mmap_sem)) {
+ current->mm->locked_vm += npage;
+ up_write(¤t->mm->mmap_sem);
+ return;
+ }
+
+ /*
+ * Couldn't get mmap_sem lock, so must setup to update
+ * mm->locked_vm later. If locked_vm were atomic, we
+ * wouldn't need this silliness
+ */
+ vwork = kmalloc(sizeof(struct vwork), GFP_KERNEL);
+ if (!vwork)
+ return;
+ mm = get_task_mm(current);
+ if (!mm) {
+ kfree(vwork);
+ return;
+ }
+ INIT_WORK(&vwork->work, vfio_lock_acct_bg);
+ vwork->mm = mm;
+ vwork->npage = npage;
+ schedule_work(&vwork->work);
+}
+
+/*
+ * Some mappings aren't backed by a struct page, for example an mmap'd
+ * MMIO range for our own or another device. These use a different
+ * pfn conversion and shouldn't be tracked as locked pages.
+ */
+static bool is_invalid_reserved_pfn(unsigned long pfn)
+{
+ if (pfn_valid(pfn)) {
+ bool reserved;
+ struct page *tail = pfn_to_page(pfn);
+ struct page *head = compound_head(tail);
+ reserved = !!(PageReserved(head));
+ if (head != tail) {
+ /*
+ * "head" is not a dangling pointer
+ * (compound_head takes care of that)
+ * but the hugepage may have been split
+ * from under us (and we may not hold a
+ * reference count on the head page so it can
+ * be reused before we run PageReferenced), so
+ * we've to check PageTail before returning
+ * what we just read.
+ */
+ smp_rmb();
+ if (PageTail(tail))
+ return reserved;
+ }
+ return PageReserved(tail);
+ }
+
+ return true;
+}
+
+static int put_pfn(unsigned long pfn, int prot)
+{
+ if (!is_invalid_reserved_pfn(pfn)) {
+ struct page *page = pfn_to_page(pfn);
+ if (prot & IOMMU_WRITE)
+ SetPageDirty(page);
+ put_page(page);
+ return 1;
+ }
+ return 0;
+}
+
+static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)
+{
+ struct page *page[1];
+ struct vm_area_struct *vma;
+ int ret = -EFAULT;
+
+ if (get_user_pages_fast(vaddr, 1, !!(prot & IOMMU_WRITE), page) == 1) {
+ *pfn = page_to_pfn(page[0]);
+ return 0;
+ }
+
+ down_read(¤t->mm->mmap_sem);
+
+ vma = find_vma_intersection(current->mm, vaddr, vaddr + 1);
+
+ if (vma && vma->vm_flags & VM_PFNMAP) {
+ *pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
+ if (is_invalid_reserved_pfn(*pfn))
+ ret = 0;
+ }
+
+ up_read(¤t->mm->mmap_sem);
+
+ return ret;
+}
+
+/*
+ * Attempt to pin pages. We really don't want to track all the pfns and
+ * the iommu can only map chunks of consecutive pfns anyway, so get the
+ * first page and all consecutive pages with the same locking.
+ */
+static long vfio_pin_pages(unsigned long vaddr, long npage,
+ int prot, unsigned long *pfn_base)
+{
+ unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+ bool lock_cap = capable(CAP_IPC_LOCK);
+ long ret, i;
+ bool rsvd;
+
+ if (!current->mm)
+ return -ENODEV;
+
+ ret = vaddr_get_pfn(vaddr, prot, pfn_base);
+ if (ret)
+ return ret;
+
+ rsvd = is_invalid_reserved_pfn(*pfn_base);
+
+ if (!rsvd && !lock_cap && current->mm->locked_vm + 1 > limit) {
+ put_pfn(*pfn_base, prot);
+ pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
+ limit << PAGE_SHIFT);
+ return -ENOMEM;
+ }
+
+ if (unlikely(disable_hugepages)) {
+ if (!rsvd)
+ vfio_lock_acct(1);
+ return 1;
+ }
+
+ /* Lock all the consecutive pages from pfn_base */
+ for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) {
+ unsigned long pfn = 0;
+
+ ret = vaddr_get_pfn(vaddr, prot, &pfn);
+ if (ret)
+ break;
+
+ if (pfn != *pfn_base + i ||
+ rsvd != is_invalid_reserved_pfn(pfn)) {
+ put_pfn(pfn, prot);
+ break;
+ }
+
+ if (!rsvd && !lock_cap &&
+ current->mm->locked_vm + i + 1 > limit) {
+ put_pfn(pfn, prot);
+ pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
+ __func__, limit << PAGE_SHIFT);
+ break;
+ }
+ }
+
+ if (!rsvd)
+ vfio_lock_acct(i);
+
+ return i;
+}
+
+static long vfio_unpin_pages(unsigned long pfn, long npage,
+ int prot, bool do_accounting)
+{
+ unsigned long unlocked = 0;
+ long i;
+
+ for (i = 0; i < npage; i++)
+ unlocked += put_pfn(pfn++, prot);
+
+ if (do_accounting)
+ vfio_lock_acct(-unlocked);
+
+ return unlocked;
+}
+
+static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
+{
+ dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
+ struct vfio_domain *domain, *d;
+ long unlocked = 0;
+
+ if (!dma->size)
+ return;
+ /*
+ * We use the IOMMU to track the physical addresses, otherwise we'd
+ * need a much more complicated tracking system. Unfortunately that
+ * means we need to use one of the iommu domains to figure out the
+ * pfns to unpin. The rest need to be unmapped in advance so we have
+ * no iommu translations remaining when the pages are unpinned.
+ */
+ domain = d = list_first_entry(&iommu->domain_list,
+ struct vfio_domain, next);
+
+ list_for_each_entry_continue(d, &iommu->domain_list, next) {
+ iommu_unmap(d->domain, dma->iova, dma->size);
+ cond_resched();
+ }
+
+ while (iova < end) {
+ size_t unmapped, len;
+ phys_addr_t phys, next;
+
+ phys = iommu_iova_to_phys(domain->domain, iova);
+ if (WARN_ON(!phys)) {
+ iova += PAGE_SIZE;
+ continue;
+ }
+
+ /*
+ * To optimize for fewer iommu_unmap() calls, each of which
+ * may require hardware cache flushing, try to find the
+ * largest contiguous physical memory chunk to unmap.
+ */
+ for (len = PAGE_SIZE;
+ !domain->fgsp && iova + len < end; len += PAGE_SIZE) {
+ next = iommu_iova_to_phys(domain->domain, iova + len);
+ if (next != phys + len)
+ break;
+ }
+
+ unmapped = iommu_unmap(domain->domain, iova, len);
+ if (WARN_ON(!unmapped))
+ break;
+
+ unlocked += vfio_unpin_pages(phys >> PAGE_SHIFT,
+ unmapped >> PAGE_SHIFT,
+ dma->prot, false);
+ iova += unmapped;
+
+ cond_resched();
+ }
+
+ vfio_lock_acct(-unlocked);
+}
+
+static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
+{
+ vfio_unmap_unpin(iommu, dma);
+ vfio_unlink_dma(iommu, dma);
+ kfree(dma);
+}
+
+static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu)
+{
+ struct vfio_domain *domain;
+ unsigned long bitmap = PAGE_MASK;
+
+ mutex_lock(&iommu->lock);
+ list_for_each_entry(domain, &iommu->domain_list, next)
+ bitmap &= domain->domain->ops->pgsize_bitmap;
+ mutex_unlock(&iommu->lock);
+
+ return bitmap;
+}
+
+static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
+ struct vfio_iommu_type1_dma_unmap *unmap)
+{
+ uint64_t mask;
+ struct vfio_dma *dma;
+ size_t unmapped = 0;
+ int ret = 0;
+
+ mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
+
+ if (unmap->iova & mask)
+ return -EINVAL;
+ if (!unmap->size || unmap->size & mask)
+ return -EINVAL;
+
+ WARN_ON(mask & PAGE_MASK);
+
+ mutex_lock(&iommu->lock);
+
+ /*
+ * vfio-iommu-type1 (v1) - User mappings were coalesced together to
+ * avoid tracking individual mappings. This means that the granularity
+ * of the original mapping was lost and the user was allowed to attempt
+ * to unmap any range. Depending on the contiguousness of physical
+ * memory and page sizes supported by the IOMMU, arbitrary unmaps may
+ * or may not have worked. We only guaranteed unmap granularity
+ * matching the original mapping; even though it was untracked here,
+ * the original mappings are reflected in IOMMU mappings. This
+ * resulted in a couple unusual behaviors. First, if a range is not
+ * able to be unmapped, ex. a set of 4k pages that was mapped as a
+ * 2M hugepage into the IOMMU, the unmap ioctl returns success but with
+ * a zero sized unmap. Also, if an unmap request overlaps the first
+ * address of a hugepage, the IOMMU will unmap the entire hugepage.
+ * This also returns success and the returned unmap size reflects the
+ * actual size unmapped.
+ *
+ * We attempt to maintain compatibility with this "v1" interface, but
+ * we take control out of the hands of the IOMMU. Therefore, an unmap
+ * request offset from the beginning of the original mapping will
+ * return success with zero sized unmap. And an unmap request covering
+ * the first iova of mapping will unmap the entire range.
+ *
+ * The v2 version of this interface intends to be more deterministic.
+ * Unmap requests must fully cover previous mappings. Multiple
+ * mappings may still be unmaped by specifying large ranges, but there
+ * must not be any previous mappings bisected by the range. An error
+ * will be returned if these conditions are not met. The v2 interface
+ * will only return success and a size of zero if there were no
+ * mappings within the range.
+ */
+ if (iommu->v2) {
+ dma = vfio_find_dma(iommu, unmap->iova, 0);
+ if (dma && dma->iova != unmap->iova) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+ dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0);
+ if (dma && dma->iova + dma->size != unmap->iova + unmap->size) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+ }
+
+ while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
+ if (!iommu->v2 && unmap->iova > dma->iova)
+ break;
+ unmapped += dma->size;
+ vfio_remove_dma(iommu, dma);
+ }
+
+unlock:
+ mutex_unlock(&iommu->lock);
+
+ /* Report how much was unmapped */
+ unmap->size = unmapped;
+
+ return ret;
+}
+
+/*
+ * Turns out AMD IOMMU has a page table bug where it won't map large pages
+ * to a region that previously mapped smaller pages. This should be fixed
+ * soon, so this is just a temporary workaround to break mappings down into
+ * PAGE_SIZE. Better to map smaller pages than nothing.
+ */
+static int map_try_harder(struct vfio_domain *domain, dma_addr_t iova,
+ unsigned long pfn, long npage, int prot)
+{
+ long i;
+ int ret;
+
+ for (i = 0; i < npage; i++, pfn++, iova += PAGE_SIZE) {
+ ret = iommu_map(domain->domain, iova,
+ (phys_addr_t)pfn << PAGE_SHIFT,
+ PAGE_SIZE, prot | domain->prot);
+ if (ret)
+ break;
+ }
+
+ for (; i < npage && i > 0; i--, iova -= PAGE_SIZE)
+ iommu_unmap(domain->domain, iova, PAGE_SIZE);
+
+ return ret;
+}
+
+static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova,
+ unsigned long pfn, long npage, int prot)
+{
+ struct vfio_domain *d;
+ int ret;
+
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ ret = iommu_map(d->domain, iova, (phys_addr_t)pfn << PAGE_SHIFT,
+ npage << PAGE_SHIFT, prot | d->prot);
+ if (ret) {
+ if (ret != -EBUSY ||
+ map_try_harder(d, iova, pfn, npage, prot))
+ goto unwind;
+ }
+
+ cond_resched();
+ }
+
+ return 0;
+
+unwind:
+ list_for_each_entry_continue_reverse(d, &iommu->domain_list, next)
+ iommu_unmap(d->domain, iova, npage << PAGE_SHIFT);
+
+ return ret;
+}
+
+static int vfio_dma_do_map(struct vfio_iommu *iommu,
+ struct vfio_iommu_type1_dma_map *map)
+{
+ dma_addr_t iova = map->iova;
+ unsigned long vaddr = map->vaddr;
+ size_t size = map->size;
+ long npage;
+ int ret = 0, prot = 0;
+ uint64_t mask;
+ struct vfio_dma *dma;
+ unsigned long pfn;
+
+ /* Verify that none of our __u64 fields overflow */
+ if (map->size != size || map->vaddr != vaddr || map->iova != iova)
+ return -EINVAL;
+
+ mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
+
+ WARN_ON(mask & PAGE_MASK);
+
+ /* READ/WRITE from device perspective */
+ if (map->flags & VFIO_DMA_MAP_FLAG_WRITE)
+ prot |= IOMMU_WRITE;
+ if (map->flags & VFIO_DMA_MAP_FLAG_READ)
+ prot |= IOMMU_READ;
+
+ if (!prot || !size || (size | iova | vaddr) & mask)
+ return -EINVAL;
+
+ /* Don't allow IOVA or virtual address wrap */
+ if (iova + size - 1 < iova || vaddr + size - 1 < vaddr)
+ return -EINVAL;
+
+ mutex_lock(&iommu->lock);
+
+ if (vfio_find_dma(iommu, iova, size)) {
+ mutex_unlock(&iommu->lock);
+ return -EEXIST;
+ }
+
+ dma = kzalloc(sizeof(*dma), GFP_KERNEL);
+ if (!dma) {
+ mutex_unlock(&iommu->lock);
+ return -ENOMEM;
+ }
+
+ dma->iova = iova;
+ dma->vaddr = vaddr;
+ dma->prot = prot;
+
+ /* Insert zero-sized and grow as we map chunks of it */
+ vfio_link_dma(iommu, dma);
+
+ while (size) {
+ /* Pin a contiguous chunk of memory */
+ npage = vfio_pin_pages(vaddr + dma->size,
+ size >> PAGE_SHIFT, prot, &pfn);
+ if (npage <= 0) {
+ WARN_ON(!npage);
+ ret = (int)npage;
+ break;
+ }
+
+ /* Map it! */
+ ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, prot);
+ if (ret) {
+ vfio_unpin_pages(pfn, npage, prot, true);
+ break;
+ }
+
+ size -= npage << PAGE_SHIFT;
+ dma->size += npage << PAGE_SHIFT;
+ }
+
+ if (ret)
+ vfio_remove_dma(iommu, dma);
+
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
+static int vfio_bus_type(struct device *dev, void *data)
+{
+ struct bus_type **bus = data;
+
+ if (*bus && *bus != dev->bus)
+ return -EINVAL;
+
+ *bus = dev->bus;
+
+ return 0;
+}
+
+static int vfio_iommu_replay(struct vfio_iommu *iommu,
+ struct vfio_domain *domain)
+{
+ struct vfio_domain *d;
+ struct rb_node *n;
+ int ret;
+
+ /* Arbitrarily pick the first domain in the list for lookups */
+ d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
+ n = rb_first(&iommu->dma_list);
+
+ /* If there's not a domain, there better not be any mappings */
+ if (WARN_ON(n && !d))
+ return -EINVAL;
+
+ for (; n; n = rb_next(n)) {
+ struct vfio_dma *dma;
+ dma_addr_t iova;
+
+ dma = rb_entry(n, struct vfio_dma, node);
+ iova = dma->iova;
+
+ while (iova < dma->iova + dma->size) {
+ phys_addr_t phys = iommu_iova_to_phys(d->domain, iova);
+ size_t size;
+
+ if (WARN_ON(!phys)) {
+ iova += PAGE_SIZE;
+ continue;
+ }
+
+ size = PAGE_SIZE;
+
+ while (iova + size < dma->iova + dma->size &&
+ phys + size == iommu_iova_to_phys(d->domain,
+ iova + size))
+ size += PAGE_SIZE;
+
+ ret = iommu_map(domain->domain, iova, phys,
+ size, dma->prot | domain->prot);
+ if (ret)
+ return ret;
+
+ iova += size;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * We change our unmap behavior slightly depending on whether the IOMMU
+ * supports fine-grained superpages. IOMMUs like AMD-Vi will use a superpage
+ * for practically any contiguous power-of-two mapping we give it. This means
+ * we don't need to look for contiguous chunks ourselves to make unmapping
+ * more efficient. On IOMMUs with coarse-grained super pages, like Intel VT-d
+ * with discrete 2M/1G/512G/1T superpages, identifying contiguous chunks
+ * significantly boosts non-hugetlbfs mappings and doesn't seem to hurt when
+ * hugetlbfs is in use.
+ */
+static void vfio_test_domain_fgsp(struct vfio_domain *domain)
+{
+ struct page *pages;
+ int ret, order = get_order(PAGE_SIZE * 2);
+
+ pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
+ if (!pages)
+ return;
+
+ ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE * 2,
+ IOMMU_READ | IOMMU_WRITE | domain->prot);
+ if (!ret) {
+ size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE);
+
+ if (unmapped == PAGE_SIZE)
+ iommu_unmap(domain->domain, PAGE_SIZE, PAGE_SIZE);
+ else
+ domain->fgsp = true;
+ }
+
+ __free_pages(pages, order);
+}
+
+static int vfio_iommu_type1_attach_group(void *iommu_data,
+ struct iommu_group *iommu_group)
+{
+ struct vfio_iommu *iommu = iommu_data;
+ struct vfio_group *group, *g;
+ struct vfio_domain *domain, *d;
+ struct bus_type *bus = NULL;
+ int ret;
+
+ mutex_lock(&iommu->lock);
+
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ list_for_each_entry(g, &d->group_list, next) {
+ if (g->iommu_group != iommu_group)
+ continue;
+
+ mutex_unlock(&iommu->lock);
+ return -EINVAL;
+ }
+ }
+
+ group = kzalloc(sizeof(*group), GFP_KERNEL);
+ domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+ if (!group || !domain) {
+ ret = -ENOMEM;
+ goto out_free;
+ }
+
+ group->iommu_group = iommu_group;
+
+ /* Determine bus_type in order to allocate a domain */
+ ret = iommu_group_for_each_dev(iommu_group, &bus, vfio_bus_type);
+ if (ret)
+ goto out_free;
+
+ domain->domain = iommu_domain_alloc(bus);
+ if (!domain->domain) {
+ ret = -EIO;
+ goto out_free;
+ }
+
+ if (iommu->nesting) {
+ int attr = 1;
+
+ ret = iommu_domain_set_attr(domain->domain, DOMAIN_ATTR_NESTING,
+ &attr);
+ if (ret)
+ goto out_domain;
+ }
+
+ ret = iommu_attach_group(domain->domain, iommu_group);
+ if (ret)
+ goto out_domain;
+
+ INIT_LIST_HEAD(&domain->group_list);
+ list_add(&group->next, &domain->group_list);
+
+ if (!allow_unsafe_interrupts &&
+ !iommu_capable(bus, IOMMU_CAP_INTR_REMAP)) {
+ pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n",
+ __func__);
+ ret = -EPERM;
+ goto out_detach;
+ }
+
+ if (iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
+ domain->prot |= IOMMU_CACHE;
+
+ /*
+ * Try to match an existing compatible domain. We don't want to
+ * preclude an IOMMU driver supporting multiple bus_types and being
+ * able to include different bus_types in the same IOMMU domain, so
+ * we test whether the domains use the same iommu_ops rather than
+ * testing if they're on the same bus_type.
+ */
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ if (d->domain->ops == domain->domain->ops &&
+ d->prot == domain->prot) {
+ iommu_detach_group(domain->domain, iommu_group);
+ if (!iommu_attach_group(d->domain, iommu_group)) {
+ list_add(&group->next, &d->group_list);
+ iommu_domain_free(domain->domain);
+ kfree(domain);
+ mutex_unlock(&iommu->lock);
+ return 0;
+ }
+
+ ret = iommu_attach_group(domain->domain, iommu_group);
+ if (ret)
+ goto out_domain;
+ }
+ }
+
+ vfio_test_domain_fgsp(domain);
+
+ /* replay mappings on new domains */
+ ret = vfio_iommu_replay(iommu, domain);
+ if (ret)
+ goto out_detach;
+
+ list_add(&domain->next, &iommu->domain_list);
+
+ mutex_unlock(&iommu->lock);
+
+ return 0;
+
+out_detach:
+ iommu_detach_group(domain->domain, iommu_group);
+out_domain:
+ iommu_domain_free(domain->domain);
+out_free:
+ kfree(domain);
+ kfree(group);
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
+static void vfio_iommu_unmap_unpin_all(struct vfio_iommu *iommu)
+{
+ struct rb_node *node;
+
+ while ((node = rb_first(&iommu->dma_list)))
+ vfio_remove_dma(iommu, rb_entry(node, struct vfio_dma, node));
+}
+
+static void vfio_iommu_type1_detach_group(void *iommu_data,
+ struct iommu_group *iommu_group)
+{
+ struct vfio_iommu *iommu = iommu_data;
+ struct vfio_domain *domain;
+ struct vfio_group *group;
+
+ mutex_lock(&iommu->lock);
+
+ list_for_each_entry(domain, &iommu->domain_list, next) {
+ list_for_each_entry(group, &domain->group_list, next) {
+ if (group->iommu_group != iommu_group)
+ continue;
+
+ iommu_detach_group(domain->domain, iommu_group);
+ list_del(&group->next);
+ kfree(group);
+ /*
+ * Group ownership provides privilege, if the group
+ * list is empty, the domain goes away. If it's the
+ * last domain, then all the mappings go away too.
+ */
+ if (list_empty(&domain->group_list)) {
+ if (list_is_singular(&iommu->domain_list))
+ vfio_iommu_unmap_unpin_all(iommu);
+ iommu_domain_free(domain->domain);
+ list_del(&domain->next);
+ kfree(domain);
+ }
+ goto done;
+ }
+ }
+
+done:
+ mutex_unlock(&iommu->lock);
+}
+
+static void *vfio_iommu_type1_open(unsigned long arg)
+{
+ struct vfio_iommu *iommu;
+
+ iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
+ if (!iommu)
+ return ERR_PTR(-ENOMEM);
+
+ switch (arg) {
+ case VFIO_TYPE1_IOMMU:
+ break;
+ case VFIO_TYPE1_NESTING_IOMMU:
+ iommu->nesting = true;
+ case VFIO_TYPE1v2_IOMMU:
+ iommu->v2 = true;
+ break;
+ default:
+ kfree(iommu);
+ return ERR_PTR(-EINVAL);
+ }
+
+ INIT_LIST_HEAD(&iommu->domain_list);
+ iommu->dma_list = RB_ROOT;
+ mutex_init(&iommu->lock);
+
+ return iommu;
+}
+
+static void vfio_iommu_type1_release(void *iommu_data)
+{
+ struct vfio_iommu *iommu = iommu_data;
+ struct vfio_domain *domain, *domain_tmp;
+ struct vfio_group *group, *group_tmp;
+
+ vfio_iommu_unmap_unpin_all(iommu);
+
+ list_for_each_entry_safe(domain, domain_tmp,
+ &iommu->domain_list, next) {
+ list_for_each_entry_safe(group, group_tmp,
+ &domain->group_list, next) {
+ iommu_detach_group(domain->domain, group->iommu_group);
+ list_del(&group->next);
+ kfree(group);
+ }
+ iommu_domain_free(domain->domain);
+ list_del(&domain->next);
+ kfree(domain);
+ }
+
+ kfree(iommu);
+}
+
+static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
+{
+ struct vfio_domain *domain;
+ int ret = 1;
+
+ mutex_lock(&iommu->lock);
+ list_for_each_entry(domain, &iommu->domain_list, next) {
+ if (!(domain->prot & IOMMU_CACHE)) {
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&iommu->lock);
+
+ return ret;
+}
+
+static long vfio_iommu_type1_ioctl(void *iommu_data,
+ unsigned int cmd, unsigned long arg)
+{
+ struct vfio_iommu *iommu = iommu_data;
+ unsigned long minsz;
+
+ if (cmd == VFIO_CHECK_EXTENSION) {
+ switch (arg) {
+ case VFIO_TYPE1_IOMMU:
+ case VFIO_TYPE1v2_IOMMU:
+ case VFIO_TYPE1_NESTING_IOMMU:
+ return 1;
+ case VFIO_DMA_CC_IOMMU:
+ if (!iommu)
+ return 0;
+ return vfio_domains_have_iommu_cache(iommu);
+ default:
+ return 0;
+ }
+ } else if (cmd == VFIO_IOMMU_GET_INFO) {
+ struct vfio_iommu_type1_info info;
+
+ minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz)
+ return -EINVAL;
+
+ info.flags = 0;
+
+ info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
+
+ return copy_to_user((void __user *)arg, &info, minsz);
+
+ } else if (cmd == VFIO_IOMMU_MAP_DMA) {
+ struct vfio_iommu_type1_dma_map map;
+ uint32_t mask = VFIO_DMA_MAP_FLAG_READ |
+ VFIO_DMA_MAP_FLAG_WRITE;
+
+ minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
+
+ if (copy_from_user(&map, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (map.argsz < minsz || map.flags & ~mask)
+ return -EINVAL;
+
+ return vfio_dma_do_map(iommu, &map);
+
+ } else if (cmd == VFIO_IOMMU_UNMAP_DMA) {
+ struct vfio_iommu_type1_dma_unmap unmap;
+ long ret;
+
+ minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
+
+ if (copy_from_user(&unmap, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (unmap.argsz < minsz || unmap.flags)
+ return -EINVAL;
+
+ ret = vfio_dma_do_unmap(iommu, &unmap);
+ if (ret)
+ return ret;
+
+ return copy_to_user((void __user *)arg, &unmap, minsz);
+ }
+
+ return -ENOTTY;
+}
+
+static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
+ .name = "vfio-iommu-type1",
+ .owner = THIS_MODULE,
+ .open = vfio_iommu_type1_open,
+ .release = vfio_iommu_type1_release,
+ .ioctl = vfio_iommu_type1_ioctl,
+ .attach_group = vfio_iommu_type1_attach_group,
+ .detach_group = vfio_iommu_type1_detach_group,
+};
+
+static int __init vfio_iommu_type1_init(void)
+{
+ return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1);
+}
+
+static void __exit vfio_iommu_type1_cleanup(void)
+{
+ vfio_unregister_iommu_driver(&vfio_iommu_driver_ops_type1);
+}
+
+module_init(vfio_iommu_type1_init);
+module_exit(vfio_iommu_type1_cleanup);
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
Code Review / kvmfornfv.git / blobdiff