xref: /freebsd/sys/amd64/include/vmm_instruction_emul.h (revision a03411e84728e9b267056fd31c7d1d9d1dc1b01e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2012 NetApp, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef	_VMM_INSTRUCTION_EMUL_H_
30 #define	_VMM_INSTRUCTION_EMUL_H_
31 
32 #include <sys/mman.h>
33 
34 /*
35  * Callback functions to read and write memory regions.
36  */
37 typedef int (*mem_region_read_t)(struct vcpu *vcpu, uint64_t gpa,
38 				 uint64_t *rval, int rsize, void *arg);
39 
40 typedef int (*mem_region_write_t)(struct vcpu *vcpu, uint64_t gpa,
41 				  uint64_t wval, int wsize, void *arg);
42 
43 /*
44  * Emulate the decoded 'vie' instruction.
45  *
46  * The callbacks 'mrr' and 'mrw' emulate reads and writes to the memory region
47  * containing 'gpa'. 'mrarg' is an opaque argument that is passed into the
48  * callback functions.
49  *
50  * 'void *vm' should be 'struct vm *' when called from kernel context and
51  * 'struct vmctx *' when called from user context.
52  * s
53  */
54 int vmm_emulate_instruction(struct vcpu *vcpu, uint64_t gpa, struct vie *vie,
55     struct vm_guest_paging *paging, mem_region_read_t mrr,
56     mem_region_write_t mrw, void *mrarg);
57 
58 int vie_update_register(struct vcpu *vcpu, enum vm_reg_name reg,
59     uint64_t val, int size);
60 
61 /*
62  * Returns 1 if an alignment check exception should be injected and 0 otherwise.
63  */
64 int vie_alignment_check(int cpl, int operand_size, uint64_t cr0,
65     uint64_t rflags, uint64_t gla);
66 
67 /* Returns 1 if the 'gla' is not canonical and 0 otherwise. */
68 int vie_canonical_check(enum vm_cpu_mode cpu_mode, uint64_t gla);
69 
70 uint64_t vie_size2mask(int size);
71 
72 int vie_calculate_gla(enum vm_cpu_mode cpu_mode, enum vm_reg_name seg,
73     struct seg_desc *desc, uint64_t off, int length, int addrsize, int prot,
74     uint64_t *gla);
75 
76 #ifdef _KERNEL
77 /*
78  * APIs to fetch and decode the instruction from nested page fault handler.
79  *
80  * 'vie' must be initialized before calling 'vmm_fetch_instruction()'
81  */
82 int vmm_fetch_instruction(struct vcpu *vcpu,
83 			  struct vm_guest_paging *guest_paging,
84 			  uint64_t rip, int inst_length, struct vie *vie,
85 			  int *is_fault);
86 
87 /*
88  * Translate the guest linear address 'gla' to a guest physical address.
89  *
90  * retval	is_fault	Interpretation
91  *   0		   0		'gpa' contains result of the translation
92  *   0		   1		An exception was injected into the guest
93  * EFAULT	  N/A		An unrecoverable hypervisor error occurred
94  */
95 int vm_gla2gpa(struct vcpu *vcpu, struct vm_guest_paging *paging,
96     uint64_t gla, int prot, uint64_t *gpa, int *is_fault);
97 
98 /*
99  * Like vm_gla2gpa, but no exceptions are injected into the guest and
100  * PTEs are not changed.
101  */
102 int vm_gla2gpa_nofault(struct vcpu *vcpu, struct vm_guest_paging *paging,
103     uint64_t gla, int prot, uint64_t *gpa, int *is_fault);
104 #endif /* _KERNEL */
105 
106 void vie_restart(struct vie *vie);
107 void vie_init(struct vie *vie, const char *inst_bytes, int inst_length);
108 
109 /*
110  * Decode the instruction fetched into 'vie' so it can be emulated.
111  *
112  * 'gla' is the guest linear address provided by the hardware assist
113  * that caused the nested page table fault. It is used to verify that
114  * the software instruction decoding is in agreement with the hardware.
115  *
116  * Some hardware assists do not provide the 'gla' to the hypervisor.
117  * To skip the 'gla' verification for this or any other reason pass
118  * in VIE_INVALID_GLA instead.
119  */
120 #ifdef _KERNEL
121 #define	VIE_INVALID_GLA		(1UL << 63)	/* a non-canonical address */
122 int vmm_decode_instruction(struct vcpu *vcpu, uint64_t gla,
123 			   enum vm_cpu_mode cpu_mode, int csd, struct vie *vie);
124 #else /* !_KERNEL */
125 /*
126  * Permit instruction decoding logic to be compiled outside of the kernel for
127  * rapid iteration and validation.  No GLA validation is performed, obviously.
128  */
129 int vmm_decode_instruction(enum vm_cpu_mode cpu_mode, int csd,
130     struct vie *vie);
131 #endif	/* _KERNEL */
132 
133 #endif	/* _VMM_INSTRUCTION_EMUL_H_ */
134