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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
// Copyright 2019 The gVisor Authors.
//
// 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 arm64
package kvm
import (
"syscall"
"gvisor.dev/gvisor/pkg/ring0"
"gvisor.dev/gvisor/pkg/sentry/arch"
)
var (
// The action for bluepillSignal is changed by sigaction().
bluepillSignal = syscall.SIGILL
// vcpuSErrBounce is the event of system error for bouncing KVM.
vcpuSErrBounce = kvmVcpuEvents{
exception: exception{
sErrPending: 1,
},
}
// vcpuSErrNMI is the event of system error to trigger sigbus.
vcpuSErrNMI = kvmVcpuEvents{
exception: exception{
sErrPending: 1,
sErrHasEsr: 1,
sErrEsr: _ESR_ELx_SERR_NMI,
},
}
// vcpuExtDabt is the event of ext_dabt.
vcpuExtDabt = kvmVcpuEvents{
exception: exception{
extDabtPending: 1,
},
}
)
// getTLS returns the value of TPIDR_EL0 register.
//
//go:nosplit
func getTLS() (value uint64)
// setTLS writes the TPIDR_EL0 value.
//
//go:nosplit
func setTLS(value uint64)
// bluepillArchEnter is called during bluepillEnter.
//
//go:nosplit
func bluepillArchEnter(context *arch.SignalContext64) (c *vCPU) {
c = vCPUPtr(uintptr(context.Regs[8]))
regs := c.CPU.Registers()
regs.Regs = context.Regs
regs.Sp = context.Sp
regs.Pc = context.Pc
regs.Pstate = context.Pstate
regs.Pstate &^= uint64(ring0.PsrFlagsClear)
regs.Pstate |= ring0.KernelFlagsSet
regs.TPIDR_EL0 = getTLS()
return
}
// bluepillArchExit is called during bluepillEnter.
//
//go:nosplit
func bluepillArchExit(c *vCPU, context *arch.SignalContext64) {
regs := c.CPU.Registers()
context.Regs = regs.Regs
context.Sp = regs.Sp
context.Pc = regs.Pc
context.Pstate = regs.Pstate
context.Pstate &^= uint64(ring0.PsrFlagsClear)
context.Pstate |= ring0.UserFlagsSet
setTLS(regs.TPIDR_EL0)
lazyVfp := c.GetLazyVFP()
if lazyVfp != 0 {
fpsimd := fpsimdPtr((*byte)(c.floatingPointState))
context.Fpsimd64.Fpsr = fpsimd.Fpsr
context.Fpsimd64.Fpcr = fpsimd.Fpcr
context.Fpsimd64.Vregs = fpsimd.Vregs
}
}
// KernelSyscall handles kernel syscalls.
//
// +checkescape:all
//
//go:nosplit
func (c *vCPU) KernelSyscall() {
regs := c.Registers()
if regs.Regs[8] != ^uint64(0) {
regs.Pc -= 4 // Rewind.
}
fpDisableTrap := ring0.CPACREL1()
if fpDisableTrap != 0 {
fpsimd := fpsimdPtr((*byte)(c.floatingPointState))
fpcr := ring0.GetFPCR()
fpsr := ring0.GetFPSR()
fpsimd.Fpcr = uint32(fpcr)
fpsimd.Fpsr = uint32(fpsr)
ring0.SaveVRegs((*byte)(c.floatingPointState))
}
ring0.Halt()
}
// KernelException handles kernel exceptions.
//
// +checkescape:all
//
//go:nosplit
func (c *vCPU) KernelException(vector ring0.Vector) {
regs := c.Registers()
if vector == ring0.Vector(bounce) {
regs.Pc = 0
}
fpDisableTrap := ring0.CPACREL1()
if fpDisableTrap != 0 {
fpsimd := fpsimdPtr((*byte)(c.floatingPointState))
fpcr := ring0.GetFPCR()
fpsr := ring0.GetFPSR()
fpsimd.Fpcr = uint32(fpcr)
fpsimd.Fpsr = uint32(fpsr)
ring0.SaveVRegs((*byte)(c.floatingPointState))
}
ring0.Halt()
}
|
