1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020 - Google LLC
4 * Author: Quentin Perret <qperret@google.com>
5 */
6
7 #include <linux/kvm_host.h>
8 #include <linux/memblock.h>
9 #include <linux/sort.h>
10
11 #include <asm/kvm_host.h>
12
13 #include <nvhe/memory.h>
14 #include <nvhe/mm.h>
15
16 static struct memblock_region *hyp_memory = kvm_nvhe_sym(hyp_memory);
17 static unsigned int *hyp_memblock_nr_ptr = &kvm_nvhe_sym(hyp_memblock_nr);
18
19 phys_addr_t hyp_mem_base;
20 phys_addr_t hyp_mem_size;
21
cmp_hyp_memblock(const void * p1,const void * p2)22 static int cmp_hyp_memblock(const void *p1, const void *p2)
23 {
24 const struct memblock_region *r1 = p1;
25 const struct memblock_region *r2 = p2;
26
27 return r1->base < r2->base ? -1 : (r1->base > r2->base);
28 }
29
sort_memblock_regions(void)30 static void __init sort_memblock_regions(void)
31 {
32 sort(hyp_memory,
33 *hyp_memblock_nr_ptr,
34 sizeof(struct memblock_region),
35 cmp_hyp_memblock,
36 NULL);
37 }
38
register_memblock_regions(void)39 static int __init register_memblock_regions(void)
40 {
41 struct memblock_region *reg;
42
43 for_each_mem_region(reg) {
44 if (*hyp_memblock_nr_ptr >= HYP_MEMBLOCK_REGIONS)
45 return -ENOMEM;
46
47 hyp_memory[*hyp_memblock_nr_ptr] = *reg;
48 (*hyp_memblock_nr_ptr)++;
49 }
50 sort_memblock_regions();
51
52 return 0;
53 }
54
kvm_hyp_reserve(void)55 void __init kvm_hyp_reserve(void)
56 {
57 u64 nr_pages, prev, hyp_mem_pages = 0;
58 int ret;
59
60 if (!is_hyp_mode_available() || is_kernel_in_hyp_mode())
61 return;
62
63 if (kvm_get_mode() != KVM_MODE_PROTECTED)
64 return;
65
66 ret = register_memblock_regions();
67 if (ret) {
68 *hyp_memblock_nr_ptr = 0;
69 kvm_err("Failed to register hyp memblocks: %d\n", ret);
70 return;
71 }
72
73 hyp_mem_pages += hyp_s1_pgtable_pages();
74 hyp_mem_pages += host_s2_mem_pgtable_pages();
75 hyp_mem_pages += host_s2_dev_pgtable_pages();
76
77 /*
78 * The hyp_vmemmap needs to be backed by pages, but these pages
79 * themselves need to be present in the vmemmap, so compute the number
80 * of pages needed by looking for a fixed point.
81 */
82 nr_pages = 0;
83 do {
84 prev = nr_pages;
85 nr_pages = hyp_mem_pages + prev;
86 nr_pages = DIV_ROUND_UP(nr_pages * sizeof(struct hyp_page), PAGE_SIZE);
87 nr_pages += __hyp_pgtable_max_pages(nr_pages);
88 } while (nr_pages != prev);
89 hyp_mem_pages += nr_pages;
90
91 /*
92 * Try to allocate a PMD-aligned region to reduce TLB pressure once
93 * this is unmapped from the host stage-2, and fallback to PAGE_SIZE.
94 */
95 hyp_mem_size = hyp_mem_pages << PAGE_SHIFT;
96 hyp_mem_base = memblock_find_in_range(0, memblock_end_of_DRAM(),
97 ALIGN(hyp_mem_size, PMD_SIZE),
98 PMD_SIZE);
99 if (!hyp_mem_base)
100 hyp_mem_base = memblock_find_in_range(0, memblock_end_of_DRAM(),
101 hyp_mem_size, PAGE_SIZE);
102 else
103 hyp_mem_size = ALIGN(hyp_mem_size, PMD_SIZE);
104
105 if (!hyp_mem_base) {
106 kvm_err("Failed to reserve hyp memory\n");
107 return;
108 }
109 memblock_reserve(hyp_mem_base, hyp_mem_size);
110
111 kvm_info("Reserved %lld MiB at 0x%llx\n", hyp_mem_size >> 20,
112 hyp_mem_base);
113 }
114