summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/xen/page.h
blob: 85e63d58c07463da177eaca4fe359cf264d0f3f6 (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
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_XEN_PAGE_H
#define _ASM_X86_XEN_PAGE_H

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/pfn.h>
#include <linux/mm.h>
#include <linux/device.h>

#include <asm/extable.h>
#include <asm/page.h>

#include <xen/interface/xen.h>
#include <xen/interface/grant_table.h>
#include <xen/features.h>

/* Xen machine address */
typedef struct xmaddr {
	phys_addr_t maddr;
} xmaddr_t;

/* Xen pseudo-physical address */
typedef struct xpaddr {
	phys_addr_t paddr;
} xpaddr_t;

#ifdef CONFIG_X86_64
#define XEN_PHYSICAL_MASK	__sme_clr((1UL << 52) - 1)
#else
#define XEN_PHYSICAL_MASK	__PHYSICAL_MASK
#endif

#define XEN_PTE_MFN_MASK	((pteval_t)(((signed long)PAGE_MASK) & \
					    XEN_PHYSICAL_MASK))

#define XMADDR(x)	((xmaddr_t) { .maddr = (x) })
#define XPADDR(x)	((xpaddr_t) { .paddr = (x) })

/**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
#define INVALID_P2M_ENTRY	(~0UL)
#define FOREIGN_FRAME_BIT	(1UL<<(BITS_PER_LONG-1))
#define IDENTITY_FRAME_BIT	(1UL<<(BITS_PER_LONG-2))
#define FOREIGN_FRAME(m)	((m) | FOREIGN_FRAME_BIT)
#define IDENTITY_FRAME(m)	((m) | IDENTITY_FRAME_BIT)

#define P2M_PER_PAGE		(PAGE_SIZE / sizeof(unsigned long))

extern unsigned long *machine_to_phys_mapping;
extern unsigned long  machine_to_phys_nr;
extern unsigned long *xen_p2m_addr;
extern unsigned long  xen_p2m_size;
extern unsigned long  xen_max_p2m_pfn;

extern int xen_alloc_p2m_entry(unsigned long pfn);

extern unsigned long get_phys_to_machine(unsigned long pfn);
extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
extern unsigned long __init set_phys_range_identity(unsigned long pfn_s,
						    unsigned long pfn_e);

#ifdef CONFIG_XEN_PV
extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
				   struct gnttab_map_grant_ref *kmap_ops,
				   struct page **pages, unsigned int count);
extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
				     struct gnttab_unmap_grant_ref *kunmap_ops,
				     struct page **pages, unsigned int count);
#else
static inline int
set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
			struct gnttab_map_grant_ref *kmap_ops,
			struct page **pages, unsigned int count)
{
	return 0;
}

static inline int
clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
			  struct gnttab_unmap_grant_ref *kunmap_ops,
			  struct page **pages, unsigned int count)
{
	return 0;
}
#endif

/*
 * Helper functions to write or read unsigned long values to/from
 * memory, when the access may fault.
 */
static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
{
	int ret = 0;

	asm volatile("1: mov %[val], %[ptr]\n"
		     "2:\n"
		     _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %[ret])
		     : [ret] "+r" (ret), [ptr] "=m" (*addr)
		     : [val] "r" (val));

	return ret;
}

static inline int xen_safe_read_ulong(const unsigned long *addr,
				      unsigned long *val)
{
	unsigned long rval = ~0ul;
	int ret = 0;

	asm volatile("1: mov %[ptr], %[rval]\n"
		     "2:\n"
		     _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %[ret])
		     : [ret] "+r" (ret), [rval] "+r" (rval)
		     : [ptr] "m" (*addr));
	*val = rval;

	return ret;
}

#ifdef CONFIG_XEN_PV
/*
 * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
 * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
 *   bits (identity or foreign) are set.
 * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
 *   identity or foreign indicator will be still set. __pfn_to_mfn() is
 *   encapsulating get_phys_to_machine() which is called in special cases only.
 * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
 *   cases needing an extended handling.
 */
static inline unsigned long __pfn_to_mfn(unsigned long pfn)
{
	unsigned long mfn;

	if (pfn < xen_p2m_size)
		mfn = xen_p2m_addr[pfn];
	else if (unlikely(pfn < xen_max_p2m_pfn))
		return get_phys_to_machine(pfn);
	else
		return IDENTITY_FRAME(pfn);

	if (unlikely(mfn == INVALID_P2M_ENTRY))
		return get_phys_to_machine(pfn);

	return mfn;
}
#else
static inline unsigned long __pfn_to_mfn(unsigned long pfn)
{
	return pfn;
}
#endif

static inline unsigned long pfn_to_mfn(unsigned long pfn)
{
	unsigned long mfn;

	/*
	 * Some x86 code are still using pfn_to_mfn instead of
	 * pfn_to_mfn. This will have to be removed when we figured
	 * out which call.
	 */
	if (xen_feature(XENFEAT_auto_translated_physmap))
		return pfn;

	mfn = __pfn_to_mfn(pfn);

	if (mfn != INVALID_P2M_ENTRY)
		mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);

	return mfn;
}

static inline int phys_to_machine_mapping_valid(unsigned long pfn)
{
	if (xen_feature(XENFEAT_auto_translated_physmap))
		return 1;

	return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
}

static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
{
	unsigned long pfn;
	int ret;

	if (unlikely(mfn >= machine_to_phys_nr))
		return ~0;

	/*
	 * The array access can fail (e.g., device space beyond end of RAM).
	 * In such cases it doesn't matter what we return (we return garbage),
	 * but we must handle the fault without crashing!
	 */
	ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
	if (ret < 0)
		return ~0;

	return pfn;
}

static inline unsigned long mfn_to_pfn(unsigned long mfn)
{
	unsigned long pfn;

	/*
	 * Some x86 code are still using mfn_to_pfn instead of
	 * gfn_to_pfn. This will have to be removed when we figure
	 * out which call.
	 */
	if (xen_feature(XENFEAT_auto_translated_physmap))
		return mfn;

	pfn = mfn_to_pfn_no_overrides(mfn);
	if (__pfn_to_mfn(pfn) != mfn)
		pfn = ~0;

	/*
	 * pfn is ~0 if there are no entries in the m2p for mfn or the
	 * entry doesn't map back to the mfn.
	 */
	if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
		pfn = mfn;

	return pfn;
}

static inline xmaddr_t phys_to_machine(xpaddr_t phys)
{
	unsigned offset = phys.paddr & ~PAGE_MASK;
	return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
}

static inline xpaddr_t machine_to_phys(xmaddr_t machine)
{
	unsigned offset = machine.maddr & ~PAGE_MASK;
	return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
}

/* Pseudo-physical <-> Guest conversion */
static inline unsigned long pfn_to_gfn(unsigned long pfn)
{
	if (xen_feature(XENFEAT_auto_translated_physmap))
		return pfn;
	else
		return pfn_to_mfn(pfn);
}

static inline unsigned long gfn_to_pfn(unsigned long gfn)
{
	if (xen_feature(XENFEAT_auto_translated_physmap))
		return gfn;
	else
		return mfn_to_pfn(gfn);
}

/* Pseudo-physical <-> Bus conversion */
#define pfn_to_bfn(pfn)		pfn_to_gfn(pfn)
#define bfn_to_pfn(bfn)		gfn_to_pfn(bfn)

/*
 * We detect special mappings in one of two ways:
 *  1. If the MFN is an I/O page then Xen will set the m2p entry
 *     to be outside our maximum possible pseudophys range.
 *  2. If the MFN belongs to a different domain then we will certainly
 *     not have MFN in our p2m table. Conversely, if the page is ours,
 *     then we'll have p2m(m2p(MFN))==MFN.
 * If we detect a special mapping then it doesn't have a 'struct page'.
 * We force !pfn_valid() by returning an out-of-range pointer.
 *
 * NB. These checks require that, for any MFN that is not in our reservation,
 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
 *
 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
 *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
 *      require. In all the cases we care about, the FOREIGN_FRAME bit is
 *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
 */
static inline unsigned long bfn_to_local_pfn(unsigned long mfn)
{
	unsigned long pfn;

	if (xen_feature(XENFEAT_auto_translated_physmap))
		return mfn;

	pfn = mfn_to_pfn(mfn);
	if (__pfn_to_mfn(pfn) != mfn)
		return -1; /* force !pfn_valid() */
	return pfn;
}

/* VIRT <-> MACHINE conversion */
#define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))
static inline unsigned long virt_to_pfn(const void *v)
{
	return PFN_DOWN(__pa(v));
}
#define virt_to_mfn(v)		(pfn_to_mfn(virt_to_pfn(v)))
#define mfn_to_virt(m)		(__va(mfn_to_pfn(m) << PAGE_SHIFT))

/* VIRT <-> GUEST conversion */
#define virt_to_gfn(v)		(pfn_to_gfn(virt_to_pfn(v)))
#define gfn_to_virt(g)		(__va(gfn_to_pfn(g) << PAGE_SHIFT))

static inline unsigned long pte_mfn(pte_t pte)
{
	return (pte.pte & XEN_PTE_MFN_MASK) >> PAGE_SHIFT;
}

static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
{
	pte_t pte;

	pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
			massage_pgprot(pgprot);

	return pte;
}

static inline pteval_t pte_val_ma(pte_t pte)
{
	return pte.pte;
}

static inline pte_t __pte_ma(pteval_t x)
{
	return (pte_t) { .pte = x };
}

#define pmd_val_ma(v) ((v).pmd)
#ifdef __PAGETABLE_PUD_FOLDED
#define pud_val_ma(v) ((v).p4d.pgd.pgd)
#else
#define pud_val_ma(v) ((v).pud)
#endif
#define __pmd_ma(x)	((pmd_t) { (x) } )

#ifdef __PAGETABLE_P4D_FOLDED
#define p4d_val_ma(x)	((x).pgd.pgd)
#else
#define p4d_val_ma(x)	((x).p4d)
#endif

xmaddr_t arbitrary_virt_to_machine(void *address);
unsigned long arbitrary_virt_to_mfn(void *vaddr);
void make_lowmem_page_readonly(void *vaddr);
void make_lowmem_page_readwrite(void *vaddr);

static inline bool xen_arch_need_swiotlb(struct device *dev,
					 phys_addr_t phys,
					 dma_addr_t dev_addr)
{
	return false;
}

#endif /* _ASM_X86_XEN_PAGE_H */