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
|
// Copyright 2018 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build amd64
package kvm
import (
"fmt"
"sync/atomic"
"syscall"
"unsafe"
"gvisor.googlesource.com/gvisor/pkg/abi/linux"
"gvisor.googlesource.com/gvisor/pkg/sentry/time"
)
// setMemoryRegion initializes a region.
//
// This may be called from bluepillHandler, and therefore returns an errno
// directly (instead of wrapping in an error) to avoid allocations.
//
//go:nosplit
func (m *machine) setMemoryRegion(slot int, physical, length, virtual uintptr) syscall.Errno {
userRegion := userMemoryRegion{
slot: uint32(slot),
flags: 0,
guestPhysAddr: uint64(physical),
memorySize: uint64(length),
userspaceAddr: uint64(virtual),
}
// Set the region.
_, _, errno := syscall.RawSyscall(
syscall.SYS_IOCTL,
uintptr(m.fd),
_KVM_SET_USER_MEMORY_REGION,
uintptr(unsafe.Pointer(&userRegion)))
return errno
}
// loadSegments copies the current segments.
//
// This may be called from within the signal context and throws on error.
//
//go:nosplit
func (c *vCPU) loadSegments(tid uint64) {
if _, _, errno := syscall.RawSyscall(
syscall.SYS_ARCH_PRCTL,
linux.ARCH_GET_FS,
uintptr(unsafe.Pointer(&c.CPU.Registers().Fs_base)),
0); errno != 0 {
throw("getting FS segment")
}
if _, _, errno := syscall.RawSyscall(
syscall.SYS_ARCH_PRCTL,
linux.ARCH_GET_GS,
uintptr(unsafe.Pointer(&c.CPU.Registers().Gs_base)),
0); errno != 0 {
throw("getting GS segment")
}
atomic.StoreUint64(&c.tid, tid)
}
// setCPUID sets the CPUID to be used by the guest.
func (c *vCPU) setCPUID() error {
if _, _, errno := syscall.RawSyscall(
syscall.SYS_IOCTL,
uintptr(c.fd),
_KVM_SET_CPUID2,
uintptr(unsafe.Pointer(&cpuidSupported))); errno != 0 {
return fmt.Errorf("error setting CPUID: %v", errno)
}
return nil
}
// setSystemTime sets the TSC for the vCPU.
//
// FIXME: This introduces a slight TSC offset between host and
// guest, which may vary per vCPU.
func (c *vCPU) setSystemTime() error {
const _MSR_IA32_TSC = 0x00000010
registers := modelControlRegisters{
nmsrs: 1,
}
registers.entries[0] = modelControlRegister{
index: _MSR_IA32_TSC,
data: uint64(time.Rdtsc()),
}
if _, _, errno := syscall.RawSyscall(
syscall.SYS_IOCTL,
uintptr(c.fd),
_KVM_SET_MSRS,
uintptr(unsafe.Pointer(®isters))); errno != 0 {
return fmt.Errorf("error setting system time: %v", errno)
}
return nil
}
// setSignalMask sets the vCPU signal mask.
//
// This must be called prior to running the vCPU.
func (c *vCPU) setSignalMask() error {
// The layout of this structure implies that it will not necessarily be
// the same layout chosen by the Go compiler. It gets fudged here.
var data struct {
length uint32
mask1 uint32
mask2 uint32
_ uint32
}
data.length = 8 // Fixed sigset size.
data.mask1 = ^uint32(bounceSignalMask & 0xffffffff)
data.mask2 = ^uint32(bounceSignalMask >> 32)
if _, _, errno := syscall.RawSyscall(
syscall.SYS_IOCTL,
uintptr(c.fd),
_KVM_SET_SIGNAL_MASK,
uintptr(unsafe.Pointer(&data))); errno != 0 {
return fmt.Errorf("error setting signal mask: %v", errno)
}
return nil
}
|
