1 // SPDX-License-Identifier: GPL-2.0
2
3 /*
4 * Hyper-V nested virtualization code.
5 *
6 * Copyright (C) 2018, Microsoft, Inc.
7 *
8 * Author : Lan Tianyu <Tianyu.Lan@microsoft.com>
9 */
10 #define pr_fmt(fmt) "Hyper-V: " fmt
11
12
13 #include <linux/types.h>
14 #include <asm/hyperv-tlfs.h>
15 #include <asm/mshyperv.h>
16 #include <asm/tlbflush.h>
17
18 #include <asm/trace/hyperv.h>
19
hyperv_flush_guest_mapping(u64 as)20 int hyperv_flush_guest_mapping(u64 as)
21 {
22 struct hv_guest_mapping_flush **flush_pcpu;
23 struct hv_guest_mapping_flush *flush;
24 u64 status;
25 unsigned long flags;
26 int ret = -ENOTSUPP;
27
28 if (!hv_hypercall_pg)
29 goto fault;
30
31 local_irq_save(flags);
32
33 flush_pcpu = (struct hv_guest_mapping_flush **)
34 this_cpu_ptr(hyperv_pcpu_input_arg);
35
36 flush = *flush_pcpu;
37
38 if (unlikely(!flush)) {
39 local_irq_restore(flags);
40 goto fault;
41 }
42
43 flush->address_space = as;
44 flush->flags = 0;
45
46 status = hv_do_hypercall(HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE,
47 flush, NULL);
48 local_irq_restore(flags);
49
50 if (!(status & HV_HYPERCALL_RESULT_MASK))
51 ret = 0;
52
53 fault:
54 trace_hyperv_nested_flush_guest_mapping(as, ret);
55 return ret;
56 }
57 EXPORT_SYMBOL_GPL(hyperv_flush_guest_mapping);
58
hyperv_fill_flush_guest_mapping_list(struct hv_guest_mapping_flush_list * flush,u64 start_gfn,u64 pages)59 int hyperv_fill_flush_guest_mapping_list(
60 struct hv_guest_mapping_flush_list *flush,
61 u64 start_gfn, u64 pages)
62 {
63 u64 cur = start_gfn;
64 u64 additional_pages;
65 int gpa_n = 0;
66
67 do {
68 /*
69 * If flush requests exceed max flush count, go back to
70 * flush tlbs without range.
71 */
72 if (gpa_n >= HV_MAX_FLUSH_REP_COUNT)
73 return -ENOSPC;
74
75 additional_pages = min_t(u64, pages, HV_MAX_FLUSH_PAGES) - 1;
76
77 flush->gpa_list[gpa_n].page.additional_pages = additional_pages;
78 flush->gpa_list[gpa_n].page.largepage = false;
79 flush->gpa_list[gpa_n].page.basepfn = cur;
80
81 pages -= additional_pages + 1;
82 cur += additional_pages + 1;
83 gpa_n++;
84 } while (pages > 0);
85
86 return gpa_n;
87 }
88 EXPORT_SYMBOL_GPL(hyperv_fill_flush_guest_mapping_list);
89
hyperv_flush_guest_mapping_range(u64 as,hyperv_fill_flush_list_func fill_flush_list_func,void * data)90 int hyperv_flush_guest_mapping_range(u64 as,
91 hyperv_fill_flush_list_func fill_flush_list_func, void *data)
92 {
93 struct hv_guest_mapping_flush_list **flush_pcpu;
94 struct hv_guest_mapping_flush_list *flush;
95 u64 status = 0;
96 unsigned long flags;
97 int ret = -ENOTSUPP;
98 int gpa_n = 0;
99
100 if (!hv_hypercall_pg || !fill_flush_list_func)
101 goto fault;
102
103 local_irq_save(flags);
104
105 flush_pcpu = (struct hv_guest_mapping_flush_list **)
106 this_cpu_ptr(hyperv_pcpu_input_arg);
107
108 flush = *flush_pcpu;
109 if (unlikely(!flush)) {
110 local_irq_restore(flags);
111 goto fault;
112 }
113
114 flush->address_space = as;
115 flush->flags = 0;
116
117 gpa_n = fill_flush_list_func(flush, data);
118 if (gpa_n < 0) {
119 local_irq_restore(flags);
120 goto fault;
121 }
122
123 status = hv_do_rep_hypercall(HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST,
124 gpa_n, 0, flush, NULL);
125
126 local_irq_restore(flags);
127
128 if (!(status & HV_HYPERCALL_RESULT_MASK))
129 ret = 0;
130 else
131 ret = status;
132 fault:
133 trace_hyperv_nested_flush_guest_mapping_range(as, ret);
134 return ret;
135 }
136 EXPORT_SYMBOL_GPL(hyperv_flush_guest_mapping_range);
137