xref: /linux/arch/arm64/include/asm/kvm_pkvm.h (revision 8e6bcc3a4502a0d8d065466efd888b6b59b85789)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2020 - Google LLC
4  * Author: Quentin Perret <qperret@google.com>
5  */
6 #ifndef __ARM64_KVM_PKVM_H__
7 #define __ARM64_KVM_PKVM_H__
8 
9 #include <linux/memblock.h>
10 #include <asm/kvm_pgtable.h>
11 
12 #define HYP_MEMBLOCK_REGIONS 128
13 
14 extern struct memblock_region kvm_nvhe_sym(hyp_memory)[];
15 extern unsigned int kvm_nvhe_sym(hyp_memblock_nr);
16 
17 static inline unsigned long
18 hyp_vmemmap_memblock_size(struct memblock_region *reg, size_t vmemmap_entry_size)
19 {
20 	unsigned long nr_pages = reg->size >> PAGE_SHIFT;
21 	unsigned long start, end;
22 
23 	start = (reg->base >> PAGE_SHIFT) * vmemmap_entry_size;
24 	end = start + nr_pages * vmemmap_entry_size;
25 	start = ALIGN_DOWN(start, PAGE_SIZE);
26 	end = ALIGN(end, PAGE_SIZE);
27 
28 	return end - start;
29 }
30 
31 static inline unsigned long hyp_vmemmap_pages(size_t vmemmap_entry_size)
32 {
33 	unsigned long res = 0, i;
34 
35 	for (i = 0; i < kvm_nvhe_sym(hyp_memblock_nr); i++) {
36 		res += hyp_vmemmap_memblock_size(&kvm_nvhe_sym(hyp_memory)[i],
37 						 vmemmap_entry_size);
38 	}
39 
40 	return res >> PAGE_SHIFT;
41 }
42 
43 static inline unsigned long __hyp_pgtable_max_pages(unsigned long nr_pages)
44 {
45 	unsigned long total = 0, i;
46 
47 	/* Provision the worst case scenario */
48 	for (i = 0; i < KVM_PGTABLE_MAX_LEVELS; i++) {
49 		nr_pages = DIV_ROUND_UP(nr_pages, PTRS_PER_PTE);
50 		total += nr_pages;
51 	}
52 
53 	return total;
54 }
55 
56 static inline unsigned long __hyp_pgtable_total_pages(void)
57 {
58 	unsigned long res = 0, i;
59 
60 	/* Cover all of memory with page-granularity */
61 	for (i = 0; i < kvm_nvhe_sym(hyp_memblock_nr); i++) {
62 		struct memblock_region *reg = &kvm_nvhe_sym(hyp_memory)[i];
63 		res += __hyp_pgtable_max_pages(reg->size >> PAGE_SHIFT);
64 	}
65 
66 	return res;
67 }
68 
69 static inline unsigned long hyp_s1_pgtable_pages(void)
70 {
71 	unsigned long res;
72 
73 	res = __hyp_pgtable_total_pages();
74 
75 	/* Allow 1 GiB for private mappings */
76 	res += __hyp_pgtable_max_pages(SZ_1G >> PAGE_SHIFT);
77 
78 	return res;
79 }
80 
81 static inline unsigned long host_s2_pgtable_pages(void)
82 {
83 	unsigned long res;
84 
85 	/*
86 	 * Include an extra 16 pages to safely upper-bound the worst case of
87 	 * concatenated pgds.
88 	 */
89 	res = __hyp_pgtable_total_pages() + 16;
90 
91 	/* Allow 1 GiB for MMIO mappings */
92 	res += __hyp_pgtable_max_pages(SZ_1G >> PAGE_SHIFT);
93 
94 	return res;
95 }
96 
97 #endif	/* __ARM64_KVM_PKVM_H__ */
98