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
20int hyperv_flush_guest_mapping(u64 as)
21{
22	struct hv_guest_mapping_flush *flush;
23	u64 status;
24	unsigned long flags;
25	int ret = -ENOTSUPP;
26
27	if (!hv_hypercall_pg)
28		goto fault;
29
30	local_irq_save(flags);
31
32	flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
33
34	if (unlikely(!flush)) {
35		local_irq_restore(flags);
36		goto fault;
37	}
38
39	flush->address_space = as;
40	flush->flags = 0;
41
42	status = hv_do_hypercall(HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE,
43				 flush, NULL);
44	local_irq_restore(flags);
45
46	if (hv_result_success(status))
47		ret = 0;
48
49fault:
50	trace_hyperv_nested_flush_guest_mapping(as, ret);
51	return ret;
52}
53EXPORT_SYMBOL_GPL(hyperv_flush_guest_mapping);
54
55int hyperv_fill_flush_guest_mapping_list(
56		struct hv_guest_mapping_flush_list *flush,
57		u64 start_gfn, u64 pages)
58{
59	u64 cur = start_gfn;
60	u64 additional_pages;
61	int gpa_n = 0;
62
63	do {
64		/*
65		 * If flush requests exceed max flush count, go back to
66		 * flush tlbs without range.
67		 */
68		if (gpa_n >= HV_MAX_FLUSH_REP_COUNT)
69			return -ENOSPC;
70
71		additional_pages = min_t(u64, pages, HV_MAX_FLUSH_PAGES) - 1;
72
73		flush->gpa_list[gpa_n].page.additional_pages = additional_pages;
74		flush->gpa_list[gpa_n].page.largepage = false;
75		flush->gpa_list[gpa_n].page.basepfn = cur;
76
77		pages -= additional_pages + 1;
78		cur += additional_pages + 1;
79		gpa_n++;
80	} while (pages > 0);
81
82	return gpa_n;
83}
84EXPORT_SYMBOL_GPL(hyperv_fill_flush_guest_mapping_list);
85
86int hyperv_flush_guest_mapping_range(u64 as,
87		hyperv_fill_flush_list_func fill_flush_list_func, void *data)
88{
89	struct hv_guest_mapping_flush_list *flush;
90	u64 status;
91	unsigned long flags;
92	int ret = -ENOTSUPP;
93	int gpa_n = 0;
94
95	if (!hv_hypercall_pg || !fill_flush_list_func)
96		goto fault;
97
98	local_irq_save(flags);
99
100	flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
101
102	if (unlikely(!flush)) {
103		local_irq_restore(flags);
104		goto fault;
105	}
106
107	flush->address_space = as;
108	flush->flags = 0;
109
110	gpa_n = fill_flush_list_func(flush, data);
111	if (gpa_n < 0) {
112		local_irq_restore(flags);
113		goto fault;
114	}
115
116	status = hv_do_rep_hypercall(HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST,
117				     gpa_n, 0, flush, NULL);
118
119	local_irq_restore(flags);
120
121	if (hv_result_success(status))
122		ret = 0;
123	else
124		ret = hv_result(status);
125fault:
126	trace_hyperv_nested_flush_guest_mapping_range(as, ret);
127	return ret;
128}
129EXPORT_SYMBOL_GPL(hyperv_flush_guest_mapping_range);
130