summaryrefslogtreecommitdiffstats
path: root/drivers/xen/xlate_mmu.c
blob: 5063c5e796b7f1a27849f191ba4b11940c3f2960 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/*
 * MMU operations common to all auto-translated physmap guests.
 *
 * Copyright (C) 2015 Citrix Systems R&D Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation; or, when distributed
 * separately from the Linux kernel or incorporated into other
 * software packages, subject to the following license:
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this source file (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */
#include <linux/kernel.h>
#include <linux/mm.h>

#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>

#include <xen/xen.h>
#include <xen/page.h>
#include <xen/interface/xen.h>
#include <xen/interface/memory.h>

typedef void (*xen_gfn_fn_t)(unsigned long gfn, void *data);

/* Break down the pages in 4KB chunk and call fn for each gfn */
static void xen_for_each_gfn(struct page **pages, unsigned nr_gfn,
			     xen_gfn_fn_t fn, void *data)
{
	unsigned long xen_pfn = 0;
	struct page *page;
	int i;

	for (i = 0; i < nr_gfn; i++) {
		if ((i % XEN_PFN_PER_PAGE) == 0) {
			page = pages[i / XEN_PFN_PER_PAGE];
			xen_pfn = page_to_xen_pfn(page);
		}
		fn(pfn_to_gfn(xen_pfn++), data);
	}
}

struct remap_data {
	xen_pfn_t *fgfn; /* foreign domain's gfn */
	int nr_fgfn; /* Number of foreign gfn left to map */
	pgprot_t prot;
	domid_t  domid;
	struct vm_area_struct *vma;
	int index;
	struct page **pages;
	struct xen_remap_gfn_info *info;
	int *err_ptr;
	int mapped;

	/* Hypercall parameters */
	int h_errs[XEN_PFN_PER_PAGE];
	xen_ulong_t h_idxs[XEN_PFN_PER_PAGE];
	xen_pfn_t h_gpfns[XEN_PFN_PER_PAGE];

	int h_iter;	/* Iterator */
};

static void setup_hparams(unsigned long gfn, void *data)
{
	struct remap_data *info = data;

	info->h_idxs[info->h_iter] = *info->fgfn;
	info->h_gpfns[info->h_iter] = gfn;
	info->h_errs[info->h_iter] = 0;

	info->h_iter++;
	info->fgfn++;
}

static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
			void *data)
{
	struct remap_data *info = data;
	struct page *page = info->pages[info->index++];
	pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), info->prot));
	int rc, nr_gfn;
	uint32_t i;
	struct xen_add_to_physmap_range xatp = {
		.domid = DOMID_SELF,
		.foreign_domid = info->domid,
		.space = XENMAPSPACE_gmfn_foreign,
	};

	nr_gfn = min_t(typeof(info->nr_fgfn), XEN_PFN_PER_PAGE, info->nr_fgfn);
	info->nr_fgfn -= nr_gfn;

	info->h_iter = 0;
	xen_for_each_gfn(&page, nr_gfn, setup_hparams, info);
	BUG_ON(info->h_iter != nr_gfn);

	set_xen_guest_handle(xatp.idxs, info->h_idxs);
	set_xen_guest_handle(xatp.gpfns, info->h_gpfns);
	set_xen_guest_handle(xatp.errs, info->h_errs);
	xatp.size = nr_gfn;

	rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);

	/* info->err_ptr expect to have one error status per Xen PFN */
	for (i = 0; i < nr_gfn; i++) {
		int err = (rc < 0) ? rc : info->h_errs[i];

		*(info->err_ptr++) = err;
		if (!err)
			info->mapped++;
	}

	/*
	 * Note: The hypercall will return 0 in most of the case if even if
	 * all the fgmfn are not mapped. We still have to update the pte
	 * as the userspace may decide to continue.
	 */
	if (!rc)
		set_pte_at(info->vma->vm_mm, addr, ptep, pte);

	return 0;
}

int xen_xlate_remap_gfn_array(struct vm_area_struct *vma,
			      unsigned long addr,
			      xen_pfn_t *gfn, int nr,
			      int *err_ptr, pgprot_t prot,
			      unsigned domid,
			      struct page **pages)
{
	int err;
	struct remap_data data;
	unsigned long range = DIV_ROUND_UP(nr, XEN_PFN_PER_PAGE) << PAGE_SHIFT;

	/* Kept here for the purpose of making sure code doesn't break
	   x86 PVOPS */
	BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO)));

	data.fgfn = gfn;
	data.nr_fgfn = nr;
	data.prot  = prot;
	data.domid = domid;
	data.vma   = vma;
	data.pages = pages;
	data.index = 0;
	data.err_ptr = err_ptr;
	data.mapped = 0;

	err = apply_to_page_range(vma->vm_mm, addr, range,
				  remap_pte_fn, &data);
	return err < 0 ? err : data.mapped;
}
EXPORT_SYMBOL_GPL(xen_xlate_remap_gfn_array);

static void unmap_gfn(unsigned long gfn, void *data)
{
	struct xen_remove_from_physmap xrp;

	xrp.domid = DOMID_SELF;
	xrp.gpfn = gfn;
	(void)HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
}

int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma,
			      int nr, struct page **pages)
{
	xen_for_each_gfn(pages, nr, unmap_gfn, NULL);

	return 0;
}
EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range);
OpenPOWER on IntegriCloud