1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <dirent.h>
3 #include <fcntl.h>
4 #include <libgen.h>
5 #include <stdint.h>
6 #include <stdlib.h>
7 #include <string.h>
8 #include <unistd.h>
9
10 #include <sys/eventfd.h>
11 #include <sys/ioctl.h>
12 #include <sys/mman.h>
13
14 #include <linux/iommufd.h>
15 #include <linux/limits.h>
16 #include <linux/mman.h>
17 #include <linux/overflow.h>
18 #include <linux/types.h>
19 #include <linux/vfio.h>
20
21 #include <libvfio.h>
22
iova_allocator_init(struct iommu * iommu)23 struct iova_allocator *iova_allocator_init(struct iommu *iommu)
24 {
25 struct iova_allocator *allocator;
26 struct iommu_iova_range *ranges;
27 u32 nranges;
28
29 ranges = iommu_iova_ranges(iommu, &nranges);
30 VFIO_ASSERT_NOT_NULL(ranges);
31
32 allocator = malloc_assert(sizeof(*allocator));
33
34 *allocator = (struct iova_allocator){
35 .ranges = ranges,
36 .nranges = nranges,
37 .range_idx = 0,
38 .range_offset = 0,
39 };
40
41 return allocator;
42 }
43
iova_allocator_cleanup(struct iova_allocator * allocator)44 void iova_allocator_cleanup(struct iova_allocator *allocator)
45 {
46 free(allocator->ranges);
47 free(allocator);
48 }
49
iova_allocator_alloc(struct iova_allocator * allocator,size_t size)50 iova_t iova_allocator_alloc(struct iova_allocator *allocator, size_t size)
51 {
52 VFIO_ASSERT_GT(size, 0, "Invalid size arg, zero\n");
53 VFIO_ASSERT_EQ(size & (size - 1), 0, "Invalid size arg, non-power-of-2\n");
54
55 for (;;) {
56 struct iommu_iova_range *range;
57 iova_t iova, last;
58
59 VFIO_ASSERT_LT(allocator->range_idx, allocator->nranges,
60 "IOVA allocator out of space\n");
61
62 range = &allocator->ranges[allocator->range_idx];
63 iova = range->start + allocator->range_offset;
64
65 /* Check for sufficient space at the current offset */
66 if (check_add_overflow(iova, size - 1, &last) ||
67 last > range->last)
68 goto next_range;
69
70 /* Align iova to size */
71 iova = last & ~(size - 1);
72
73 /* Check for sufficient space at the aligned iova */
74 if (check_add_overflow(iova, size - 1, &last) ||
75 last > range->last)
76 goto next_range;
77
78 if (last == range->last) {
79 allocator->range_idx++;
80 allocator->range_offset = 0;
81 } else {
82 allocator->range_offset = last - range->start + 1;
83 }
84
85 return iova;
86
87 next_range:
88 allocator->range_idx++;
89 allocator->range_offset = 0;
90 }
91 }
92