xref: /openbmc/qemu/target/i386/hvf/x86_descr.c (revision ffe98631)
1 /*
2  * Copyright (C) 2016 Veertu Inc,
3  * Copyright (C) 2017 Google Inc,
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this program; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include "qemu/osdep.h"
20 
21 #include "vmx.h"
22 #include "x86_descr.h"
23 
24 #define VMX_SEGMENT_FIELD(seg)                        \
25     [R_##seg] = {                                     \
26         .selector = VMCS_GUEST_##seg##_SELECTOR,      \
27         .base = VMCS_GUEST_##seg##_BASE,              \
28         .limit = VMCS_GUEST_##seg##_LIMIT,            \
29         .ar_bytes = VMCS_GUEST_##seg##_ACCESS_RIGHTS, \
30 }
31 
32 static const struct vmx_segment_field {
33     int selector;
34     int base;
35     int limit;
36     int ar_bytes;
37 } vmx_segment_fields[] = {
38     VMX_SEGMENT_FIELD(ES),
39     VMX_SEGMENT_FIELD(CS),
40     VMX_SEGMENT_FIELD(SS),
41     VMX_SEGMENT_FIELD(DS),
42     VMX_SEGMENT_FIELD(FS),
43     VMX_SEGMENT_FIELD(GS),
44     VMX_SEGMENT_FIELD(LDTR),
45     VMX_SEGMENT_FIELD(TR),
46 };
47 
48 uint32_t vmx_read_segment_limit(CPUState *cpu, X86Seg seg)
49 {
50     return (uint32_t)rvmcs(cpu->hvf->fd, vmx_segment_fields[seg].limit);
51 }
52 
53 uint32_t vmx_read_segment_ar(CPUState *cpu, X86Seg seg)
54 {
55     return (uint32_t)rvmcs(cpu->hvf->fd, vmx_segment_fields[seg].ar_bytes);
56 }
57 
58 uint64_t vmx_read_segment_base(CPUState *cpu, X86Seg seg)
59 {
60     return rvmcs(cpu->hvf->fd, vmx_segment_fields[seg].base);
61 }
62 
63 x68_segment_selector vmx_read_segment_selector(CPUState *cpu, X86Seg seg)
64 {
65     x68_segment_selector sel;
66     sel.sel = rvmcs(cpu->hvf->fd, vmx_segment_fields[seg].selector);
67     return sel;
68 }
69 
70 void vmx_write_segment_selector(struct CPUState *cpu, x68_segment_selector selector, X86Seg seg)
71 {
72     wvmcs(cpu->hvf->fd, vmx_segment_fields[seg].selector, selector.sel);
73 }
74 
75 void vmx_read_segment_descriptor(struct CPUState *cpu, struct vmx_segment *desc, X86Seg seg)
76 {
77     desc->sel = rvmcs(cpu->hvf->fd, vmx_segment_fields[seg].selector);
78     desc->base = rvmcs(cpu->hvf->fd, vmx_segment_fields[seg].base);
79     desc->limit = rvmcs(cpu->hvf->fd, vmx_segment_fields[seg].limit);
80     desc->ar = rvmcs(cpu->hvf->fd, vmx_segment_fields[seg].ar_bytes);
81 }
82 
83 void vmx_write_segment_descriptor(CPUState *cpu, struct vmx_segment *desc, X86Seg seg)
84 {
85     const struct vmx_segment_field *sf = &vmx_segment_fields[seg];
86 
87     wvmcs(cpu->hvf->fd, sf->base, desc->base);
88     wvmcs(cpu->hvf->fd, sf->limit, desc->limit);
89     wvmcs(cpu->hvf->fd, sf->selector, desc->sel);
90     wvmcs(cpu->hvf->fd, sf->ar_bytes, desc->ar);
91 }
92 
93 void x86_segment_descriptor_to_vmx(struct CPUState *cpu, x68_segment_selector selector, struct x86_segment_descriptor *desc, struct vmx_segment *vmx_desc)
94 {
95     vmx_desc->sel = selector.sel;
96     vmx_desc->base = x86_segment_base(desc);
97     vmx_desc->limit = x86_segment_limit(desc);
98 
99     vmx_desc->ar = (selector.sel ? 0 : 1) << 16 |
100                     desc->g << 15 |
101                     desc->db << 14 |
102                     desc->l << 13 |
103                     desc->avl << 12 |
104                     desc->p << 7 |
105                     desc->dpl << 5 |
106                     desc->s << 4 |
107                     desc->type;
108 }
109 
110 void vmx_segment_to_x86_descriptor(struct CPUState *cpu, struct vmx_segment *vmx_desc, struct x86_segment_descriptor *desc)
111 {
112     x86_set_segment_limit(desc, vmx_desc->limit);
113     x86_set_segment_base(desc, vmx_desc->base);
114 
115     desc->type = vmx_desc->ar & 15;
116     desc->s = (vmx_desc->ar >> 4) & 1;
117     desc->dpl = (vmx_desc->ar >> 5) & 3;
118     desc->p = (vmx_desc->ar >> 7) & 1;
119     desc->avl = (vmx_desc->ar >> 12) & 1;
120     desc->l = (vmx_desc->ar >> 13) & 1;
121     desc->db = (vmx_desc->ar >> 14) & 1;
122     desc->g = (vmx_desc->ar >> 15) & 1;
123 }
124 
125