blob: b35a178e7e0db0571ff6aba5a4fcaa08fc70749f (
plain)
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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012-2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#include <hyp/sysreg-sr.h>
#include <linux/compiler.h>
#include <linux/kvm_host.h>
#include <asm/kprobes.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_nested.h>
/*
* VHE: Host and guest must save mdscr_el1 and sp_el0 (and the PC and
* pstate, which are handled as part of the el2 return state) on every
* switch (sp_el0 is being dealt with in the assembly code).
* tpidr_el0 and tpidrro_el0 only need to be switched when going
* to host userspace or a different VCPU. EL1 registers only need to be
* switched when potentially going to run a different VCPU. The latter two
* classes are handled as part of kvm_arch_vcpu_load and kvm_arch_vcpu_put.
*/
void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt)
{
__sysreg_save_common_state(ctxt);
}
NOKPROBE_SYMBOL(sysreg_save_host_state_vhe);
void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt)
{
__sysreg_save_common_state(ctxt);
__sysreg_save_el2_return_state(ctxt);
}
NOKPROBE_SYMBOL(sysreg_save_guest_state_vhe);
void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt)
{
__sysreg_restore_common_state(ctxt);
}
NOKPROBE_SYMBOL(sysreg_restore_host_state_vhe);
void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt)
{
__sysreg_restore_common_state(ctxt);
__sysreg_restore_el2_return_state(ctxt);
}
NOKPROBE_SYMBOL(sysreg_restore_guest_state_vhe);
/**
* kvm_vcpu_load_sysregs_vhe - Load guest system registers to the physical CPU
*
* @vcpu: The VCPU pointer
*
* Load system registers that do not affect the host's execution, for
* example EL1 system registers on a VHE system where the host kernel
* runs at EL2. This function is called from KVM's vcpu_load() function
* and loading system register state early avoids having to load them on
* every entry to the VM.
*/
void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
struct kvm_cpu_context *host_ctxt;
host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
__sysreg_save_user_state(host_ctxt);
/*
* When running a normal EL1 guest, we only load a new vcpu
* after a context switch, which imvolves a DSB, so all
* speculative EL1&0 walks will have already completed.
* If running NV, the vcpu may transition between vEL1 and
* vEL2 without a context switch, so make sure we complete
* those walks before loading a new context.
*/
if (vcpu_has_nv(vcpu))
dsb(nsh);
/*
* Load guest EL1 and user state
*
* We must restore the 32-bit state before the sysregs, thanks
* to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
*/
__sysreg32_restore_state(vcpu);
__sysreg_restore_user_state(guest_ctxt);
__sysreg_restore_el1_state(guest_ctxt);
vcpu_set_flag(vcpu, SYSREGS_ON_CPU);
activate_traps_vhe_load(vcpu);
}
/**
* kvm_vcpu_put_sysregs_vhe - Restore host system registers to the physical CPU
*
* @vcpu: The VCPU pointer
*
* Save guest system registers that do not affect the host's execution, for
* example EL1 system registers on a VHE system where the host kernel
* runs at EL2. This function is called from KVM's vcpu_put() function
* and deferring saving system register state until we're no longer running the
* VCPU avoids having to save them on every exit from the VM.
*/
void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
struct kvm_cpu_context *host_ctxt;
host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
deactivate_traps_vhe_put(vcpu);
__sysreg_save_el1_state(guest_ctxt);
__sysreg_save_user_state(guest_ctxt);
__sysreg32_save_state(vcpu);
/* Restore host user state */
__sysreg_restore_user_state(host_ctxt);
vcpu_clear_flag(vcpu, SYSREGS_ON_CPU);
}
|