xref: /openbmc/qemu/target/i386/hvf/x86_descr.c (revision 61f3c91a)
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 "qemu-common.h"
22 #include "vmx.h"
23 #include "x86_descr.h"
24 
25 #define VMX_SEGMENT_FIELD(seg)                        \
26     [R_##seg] = {                                     \
27         .selector = VMCS_GUEST_##seg##_SELECTOR,      \
28         .base = VMCS_GUEST_##seg##_BASE,              \
29         .limit = VMCS_GUEST_##seg##_LIMIT,            \
30         .ar_bytes = VMCS_GUEST_##seg##_ACCESS_RIGHTS, \
31 }
32 
33 static const struct vmx_segment_field {
34     int selector;
35     int base;
36     int limit;
37     int ar_bytes;
38 } vmx_segment_fields[] = {
39     VMX_SEGMENT_FIELD(ES),
40     VMX_SEGMENT_FIELD(CS),
41     VMX_SEGMENT_FIELD(SS),
42     VMX_SEGMENT_FIELD(DS),
43     VMX_SEGMENT_FIELD(FS),
44     VMX_SEGMENT_FIELD(GS),
45     VMX_SEGMENT_FIELD(LDTR),
46     VMX_SEGMENT_FIELD(TR),
47 };
48 
49 uint32_t vmx_read_segment_limit(CPUState *cpu, X86Seg seg)
50 {
51     return (uint32_t)rvmcs(cpu->hvf_fd, vmx_segment_fields[seg].limit);
52 }
53 
54 uint32_t vmx_read_segment_ar(CPUState *cpu, X86Seg seg)
55 {
56     return (uint32_t)rvmcs(cpu->hvf_fd, vmx_segment_fields[seg].ar_bytes);
57 }
58 
59 uint64_t vmx_read_segment_base(CPUState *cpu, X86Seg seg)
60 {
61     return rvmcs(cpu->hvf_fd, vmx_segment_fields[seg].base);
62 }
63 
64 x68_segment_selector vmx_read_segment_selector(CPUState *cpu, X86Seg seg)
65 {
66     x68_segment_selector sel;
67     sel.sel = rvmcs(cpu->hvf_fd, vmx_segment_fields[seg].selector);
68     return sel;
69 }
70 
71 void vmx_write_segment_selector(struct CPUState *cpu, x68_segment_selector selector, X86Seg seg)
72 {
73     wvmcs(cpu->hvf_fd, vmx_segment_fields[seg].selector, selector.sel);
74 }
75 
76 void vmx_read_segment_descriptor(struct CPUState *cpu, struct vmx_segment *desc, X86Seg seg)
77 {
78     desc->sel = rvmcs(cpu->hvf_fd, vmx_segment_fields[seg].selector);
79     desc->base = rvmcs(cpu->hvf_fd, vmx_segment_fields[seg].base);
80     desc->limit = rvmcs(cpu->hvf_fd, vmx_segment_fields[seg].limit);
81     desc->ar = rvmcs(cpu->hvf_fd, vmx_segment_fields[seg].ar_bytes);
82 }
83 
84 void vmx_write_segment_descriptor(CPUState *cpu, struct vmx_segment *desc, X86Seg seg)
85 {
86     const struct vmx_segment_field *sf = &vmx_segment_fields[seg];
87 
88     wvmcs(cpu->hvf_fd, sf->base, desc->base);
89     wvmcs(cpu->hvf_fd, sf->limit, desc->limit);
90     wvmcs(cpu->hvf_fd, sf->selector, desc->sel);
91     wvmcs(cpu->hvf_fd, sf->ar_bytes, desc->ar);
92 }
93 
94 void x86_segment_descriptor_to_vmx(struct CPUState *cpu, x68_segment_selector selector, struct x86_segment_descriptor *desc, struct vmx_segment *vmx_desc)
95 {
96     vmx_desc->sel = selector.sel;
97     vmx_desc->base = x86_segment_base(desc);
98     vmx_desc->limit = x86_segment_limit(desc);
99 
100     vmx_desc->ar = (selector.sel ? 0 : 1) << 16 |
101                     desc->g << 15 |
102                     desc->db << 14 |
103                     desc->l << 13 |
104                     desc->avl << 12 |
105                     desc->p << 7 |
106                     desc->dpl << 5 |
107                     desc->s << 4 |
108                     desc->type;
109 }
110 
111 void vmx_segment_to_x86_descriptor(struct CPUState *cpu, struct vmx_segment *vmx_desc, struct x86_segment_descriptor *desc)
112 {
113     x86_set_segment_limit(desc, vmx_desc->limit);
114     x86_set_segment_base(desc, vmx_desc->base);
115 
116     desc->type = vmx_desc->ar & 15;
117     desc->s = (vmx_desc->ar >> 4) & 1;
118     desc->dpl = (vmx_desc->ar >> 5) & 3;
119     desc->p = (vmx_desc->ar >> 7) & 1;
120     desc->avl = (vmx_desc->ar >> 12) & 1;
121     desc->l = (vmx_desc->ar >> 13) & 1;
122     desc->db = (vmx_desc->ar >> 14) & 1;
123     desc->g = (vmx_desc->ar >> 15) & 1;
124 }
125 
126