xref: /openbmc/linux/arch/x86/kernel/cpu/sgx/encl.h (revision 36fe4655)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /**
3  * Copyright(c) 2016-20 Intel Corporation.
4  *
5  * Contains the software defined data structures for enclaves.
6  */
7 #ifndef _X86_ENCL_H
8 #define _X86_ENCL_H
9 
10 #include <linux/cpumask.h>
11 #include <linux/kref.h>
12 #include <linux/list.h>
13 #include <linux/mm_types.h>
14 #include <linux/mmu_notifier.h>
15 #include <linux/mutex.h>
16 #include <linux/notifier.h>
17 #include <linux/srcu.h>
18 #include <linux/workqueue.h>
19 #include <linux/xarray.h>
20 #include "sgx.h"
21 
22 /* 'desc' bits holding the offset in the VA (version array) page. */
23 #define SGX_ENCL_PAGE_VA_OFFSET_MASK	GENMASK_ULL(11, 3)
24 
25 /* 'desc' bit marking that the page is being reclaimed. */
26 #define SGX_ENCL_PAGE_BEING_RECLAIMED	BIT(3)
27 
28 struct sgx_encl_page {
29 	unsigned long desc;
30 	unsigned long vm_max_prot_bits;
31 	struct sgx_epc_page *epc_page;
32 	struct sgx_encl *encl;
33 	struct sgx_va_page *va_page;
34 };
35 
36 enum sgx_encl_flags {
37 	SGX_ENCL_IOCTL		= BIT(0),
38 	SGX_ENCL_DEBUG		= BIT(1),
39 	SGX_ENCL_CREATED	= BIT(2),
40 	SGX_ENCL_INITIALIZED	= BIT(3),
41 };
42 
43 struct sgx_encl_mm {
44 	struct sgx_encl *encl;
45 	struct mm_struct *mm;
46 	struct list_head list;
47 	struct mmu_notifier mmu_notifier;
48 };
49 
50 struct sgx_encl {
51 	unsigned long base;
52 	unsigned long size;
53 	unsigned long flags;
54 	unsigned int page_cnt;
55 	unsigned int secs_child_cnt;
56 	struct mutex lock;
57 	struct xarray page_array;
58 	struct sgx_encl_page secs;
59 	unsigned long attributes;
60 	unsigned long attributes_mask;
61 
62 	cpumask_t cpumask;
63 	struct file *backing;
64 	struct kref refcount;
65 	struct list_head va_pages;
66 	unsigned long mm_list_version;
67 	struct list_head mm_list;
68 	spinlock_t mm_lock;
69 	struct srcu_struct srcu;
70 };
71 
72 #define SGX_VA_SLOT_COUNT 512
73 
74 struct sgx_va_page {
75 	struct sgx_epc_page *epc_page;
76 	DECLARE_BITMAP(slots, SGX_VA_SLOT_COUNT);
77 	struct list_head list;
78 };
79 
80 struct sgx_backing {
81 	pgoff_t page_index;
82 	struct page *contents;
83 	struct page *pcmd;
84 	unsigned long pcmd_offset;
85 };
86 
87 extern const struct vm_operations_struct sgx_vm_ops;
88 
89 static inline int sgx_encl_find(struct mm_struct *mm, unsigned long addr,
90 				struct vm_area_struct **vma)
91 {
92 	struct vm_area_struct *result;
93 
94 	result = find_vma(mm, addr);
95 	if (!result || result->vm_ops != &sgx_vm_ops || addr < result->vm_start)
96 		return -EINVAL;
97 
98 	*vma = result;
99 
100 	return 0;
101 }
102 
103 int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
104 		     unsigned long end, unsigned long vm_flags);
105 
106 void sgx_encl_release(struct kref *ref);
107 int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm);
108 int sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_index,
109 			 struct sgx_backing *backing);
110 void sgx_encl_put_backing(struct sgx_backing *backing, bool do_write);
111 int sgx_encl_test_and_clear_young(struct mm_struct *mm,
112 				  struct sgx_encl_page *page);
113 
114 struct sgx_epc_page *sgx_alloc_va_page(void);
115 unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page);
116 void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset);
117 bool sgx_va_page_full(struct sgx_va_page *va_page);
118 
119 #endif /* _X86_ENCL_H */
120