8160c4e455
Calling return copy_to_user(...) in an ioctl will not do the right thing if there's a pagefault: copy_to_user returns the number of bytes not copied in this case. Fix up vfio to do return copy_to_user(...)) ? -EFAULT : 0; everywhere. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
1070 lines
27 KiB
C
1070 lines
27 KiB
C
/*
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* VFIO: IOMMU DMA mapping support for Type1 IOMMU
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*
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* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
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* Author: Alex Williamson <alex.williamson@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Derived from original vfio:
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* Copyright 2010 Cisco Systems, Inc. All rights reserved.
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* Author: Tom Lyon, pugs@cisco.com
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*
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* We arbitrarily define a Type1 IOMMU as one matching the below code.
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* It could be called the x86 IOMMU as it's designed for AMD-Vi & Intel
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* VT-d, but that makes it harder to re-use as theoretically anyone
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* implementing a similar IOMMU could make use of this. We expect the
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* IOMMU to support the IOMMU API and have few to no restrictions around
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* the IOVA range that can be mapped. The Type1 IOMMU is currently
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* optimized for relatively static mappings of a userspace process with
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* userpsace pages pinned into memory. We also assume devices and IOMMU
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* domains are PCI based as the IOMMU API is still centered around a
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* device/bus interface rather than a group interface.
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*/
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#include <linux/compat.h>
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/iommu.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/rbtree.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/vfio.h>
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#include <linux/workqueue.h>
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#define DRIVER_VERSION "0.2"
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#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
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#define DRIVER_DESC "Type1 IOMMU driver for VFIO"
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static bool allow_unsafe_interrupts;
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module_param_named(allow_unsafe_interrupts,
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allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(allow_unsafe_interrupts,
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"Enable VFIO IOMMU support for on platforms without interrupt remapping support.");
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static bool disable_hugepages;
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module_param_named(disable_hugepages,
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disable_hugepages, bool, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(disable_hugepages,
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"Disable VFIO IOMMU support for IOMMU hugepages.");
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struct vfio_iommu {
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struct list_head domain_list;
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struct mutex lock;
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struct rb_root dma_list;
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bool v2;
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bool nesting;
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};
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struct vfio_domain {
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struct iommu_domain *domain;
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struct list_head next;
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struct list_head group_list;
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int prot; /* IOMMU_CACHE */
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bool fgsp; /* Fine-grained super pages */
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};
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struct vfio_dma {
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struct rb_node node;
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dma_addr_t iova; /* Device address */
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unsigned long vaddr; /* Process virtual addr */
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size_t size; /* Map size (bytes) */
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int prot; /* IOMMU_READ/WRITE */
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};
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struct vfio_group {
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struct iommu_group *iommu_group;
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struct list_head next;
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};
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/*
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* This code handles mapping and unmapping of user data buffers
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* into DMA'ble space using the IOMMU
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*/
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static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
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dma_addr_t start, size_t size)
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{
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struct rb_node *node = iommu->dma_list.rb_node;
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while (node) {
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struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
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if (start + size <= dma->iova)
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node = node->rb_left;
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else if (start >= dma->iova + dma->size)
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node = node->rb_right;
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else
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return dma;
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}
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return NULL;
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}
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static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
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{
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struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL;
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struct vfio_dma *dma;
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while (*link) {
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parent = *link;
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dma = rb_entry(parent, struct vfio_dma, node);
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if (new->iova + new->size <= dma->iova)
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link = &(*link)->rb_left;
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else
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link = &(*link)->rb_right;
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}
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rb_link_node(&new->node, parent, link);
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rb_insert_color(&new->node, &iommu->dma_list);
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}
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static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
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{
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rb_erase(&old->node, &iommu->dma_list);
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}
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struct vwork {
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struct mm_struct *mm;
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long npage;
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struct work_struct work;
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};
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/* delayed decrement/increment for locked_vm */
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static void vfio_lock_acct_bg(struct work_struct *work)
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{
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struct vwork *vwork = container_of(work, struct vwork, work);
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struct mm_struct *mm;
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mm = vwork->mm;
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down_write(&mm->mmap_sem);
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mm->locked_vm += vwork->npage;
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up_write(&mm->mmap_sem);
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mmput(mm);
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kfree(vwork);
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}
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static void vfio_lock_acct(long npage)
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{
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struct vwork *vwork;
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struct mm_struct *mm;
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if (!current->mm || !npage)
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return; /* process exited or nothing to do */
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if (down_write_trylock(¤t->mm->mmap_sem)) {
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current->mm->locked_vm += npage;
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up_write(¤t->mm->mmap_sem);
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return;
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}
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/*
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* Couldn't get mmap_sem lock, so must setup to update
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* mm->locked_vm later. If locked_vm were atomic, we
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* wouldn't need this silliness
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*/
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vwork = kmalloc(sizeof(struct vwork), GFP_KERNEL);
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if (!vwork)
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return;
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mm = get_task_mm(current);
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if (!mm) {
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kfree(vwork);
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return;
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}
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INIT_WORK(&vwork->work, vfio_lock_acct_bg);
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vwork->mm = mm;
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vwork->npage = npage;
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schedule_work(&vwork->work);
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}
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/*
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* Some mappings aren't backed by a struct page, for example an mmap'd
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* MMIO range for our own or another device. These use a different
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* pfn conversion and shouldn't be tracked as locked pages.
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*/
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static bool is_invalid_reserved_pfn(unsigned long pfn)
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{
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if (pfn_valid(pfn)) {
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bool reserved;
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struct page *tail = pfn_to_page(pfn);
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struct page *head = compound_head(tail);
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reserved = !!(PageReserved(head));
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if (head != tail) {
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/*
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* "head" is not a dangling pointer
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* (compound_head takes care of that)
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* but the hugepage may have been split
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* from under us (and we may not hold a
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* reference count on the head page so it can
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* be reused before we run PageReferenced), so
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* we've to check PageTail before returning
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* what we just read.
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*/
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smp_rmb();
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if (PageTail(tail))
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return reserved;
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}
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return PageReserved(tail);
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}
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return true;
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}
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static int put_pfn(unsigned long pfn, int prot)
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{
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if (!is_invalid_reserved_pfn(pfn)) {
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struct page *page = pfn_to_page(pfn);
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if (prot & IOMMU_WRITE)
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SetPageDirty(page);
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put_page(page);
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return 1;
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}
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return 0;
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}
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static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)
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{
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struct page *page[1];
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struct vm_area_struct *vma;
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int ret = -EFAULT;
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if (get_user_pages_fast(vaddr, 1, !!(prot & IOMMU_WRITE), page) == 1) {
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*pfn = page_to_pfn(page[0]);
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return 0;
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}
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down_read(¤t->mm->mmap_sem);
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vma = find_vma_intersection(current->mm, vaddr, vaddr + 1);
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if (vma && vma->vm_flags & VM_PFNMAP) {
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*pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
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if (is_invalid_reserved_pfn(*pfn))
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ret = 0;
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}
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up_read(¤t->mm->mmap_sem);
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return ret;
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}
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/*
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* Attempt to pin pages. We really don't want to track all the pfns and
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* the iommu can only map chunks of consecutive pfns anyway, so get the
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* first page and all consecutive pages with the same locking.
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*/
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static long vfio_pin_pages(unsigned long vaddr, long npage,
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int prot, unsigned long *pfn_base)
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{
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unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
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bool lock_cap = capable(CAP_IPC_LOCK);
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long ret, i;
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bool rsvd;
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if (!current->mm)
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return -ENODEV;
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ret = vaddr_get_pfn(vaddr, prot, pfn_base);
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if (ret)
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return ret;
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rsvd = is_invalid_reserved_pfn(*pfn_base);
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if (!rsvd && !lock_cap && current->mm->locked_vm + 1 > limit) {
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put_pfn(*pfn_base, prot);
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pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
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limit << PAGE_SHIFT);
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return -ENOMEM;
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}
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if (unlikely(disable_hugepages)) {
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if (!rsvd)
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vfio_lock_acct(1);
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return 1;
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}
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/* Lock all the consecutive pages from pfn_base */
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for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) {
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unsigned long pfn = 0;
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ret = vaddr_get_pfn(vaddr, prot, &pfn);
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if (ret)
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break;
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if (pfn != *pfn_base + i ||
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rsvd != is_invalid_reserved_pfn(pfn)) {
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put_pfn(pfn, prot);
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break;
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}
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if (!rsvd && !lock_cap &&
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current->mm->locked_vm + i + 1 > limit) {
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put_pfn(pfn, prot);
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pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
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__func__, limit << PAGE_SHIFT);
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break;
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}
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}
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if (!rsvd)
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vfio_lock_acct(i);
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return i;
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}
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static long vfio_unpin_pages(unsigned long pfn, long npage,
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int prot, bool do_accounting)
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{
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unsigned long unlocked = 0;
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long i;
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for (i = 0; i < npage; i++)
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unlocked += put_pfn(pfn++, prot);
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if (do_accounting)
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vfio_lock_acct(-unlocked);
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return unlocked;
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}
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static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
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{
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dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
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struct vfio_domain *domain, *d;
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long unlocked = 0;
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if (!dma->size)
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return;
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/*
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* We use the IOMMU to track the physical addresses, otherwise we'd
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* need a much more complicated tracking system. Unfortunately that
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* means we need to use one of the iommu domains to figure out the
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* pfns to unpin. The rest need to be unmapped in advance so we have
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* no iommu translations remaining when the pages are unpinned.
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*/
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domain = d = list_first_entry(&iommu->domain_list,
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struct vfio_domain, next);
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list_for_each_entry_continue(d, &iommu->domain_list, next) {
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iommu_unmap(d->domain, dma->iova, dma->size);
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cond_resched();
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}
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while (iova < end) {
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size_t unmapped, len;
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phys_addr_t phys, next;
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phys = iommu_iova_to_phys(domain->domain, iova);
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if (WARN_ON(!phys)) {
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iova += PAGE_SIZE;
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continue;
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}
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|
|
|
/*
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* To optimize for fewer iommu_unmap() calls, each of which
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* may require hardware cache flushing, try to find the
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* largest contiguous physical memory chunk to unmap.
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|
*/
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for (len = PAGE_SIZE;
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!domain->fgsp && iova + len < end; len += PAGE_SIZE) {
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next = iommu_iova_to_phys(domain->domain, iova + len);
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if (next != phys + len)
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break;
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}
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unmapped = iommu_unmap(domain->domain, iova, len);
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if (WARN_ON(!unmapped))
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break;
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unlocked += vfio_unpin_pages(phys >> PAGE_SHIFT,
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unmapped >> PAGE_SHIFT,
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dma->prot, false);
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iova += unmapped;
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|
|
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cond_resched();
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}
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|
|
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vfio_lock_acct(-unlocked);
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}
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|
|
|
static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
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{
|
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vfio_unmap_unpin(iommu, dma);
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vfio_unlink_dma(iommu, dma);
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kfree(dma);
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}
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|
|
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static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu)
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{
|
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struct vfio_domain *domain;
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unsigned long bitmap = ULONG_MAX;
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|
|
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mutex_lock(&iommu->lock);
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list_for_each_entry(domain, &iommu->domain_list, next)
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bitmap &= domain->domain->ops->pgsize_bitmap;
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mutex_unlock(&iommu->lock);
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|
|
|
/*
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* In case the IOMMU supports page sizes smaller than PAGE_SIZE
|
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* we pretend PAGE_SIZE is supported and hide sub-PAGE_SIZE sizes.
|
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* That way the user will be able to map/unmap buffers whose size/
|
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* start address is aligned with PAGE_SIZE. Pinning code uses that
|
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* granularity while iommu driver can use the sub-PAGE_SIZE size
|
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* to map the buffer.
|
|
*/
|
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if (bitmap & ~PAGE_MASK) {
|
|
bitmap &= PAGE_MASK;
|
|
bitmap |= PAGE_SIZE;
|
|
}
|
|
|
|
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 = VFIO_IOMMU_INFO_PGSIZES;
|
|
|
|
info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
|
|
|
|
return copy_to_user((void __user *)arg, &info, minsz) ?
|
|
-EFAULT : 0;
|
|
|
|
} 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) ?
|
|
-EFAULT : 0;
|
|
}
|
|
|
|
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);
|