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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
#include <linux/types.h>
#include <linux/interrupt.h>
#include <asm/xen/hypercall.h>
#include <xen/page.h>
#include <xen/interface/xen.h>
#include <xen/interface/vcpu.h>
#include <xen/interface/xenpmu.h>
#include "xen-ops.h"
#include "pmu.h"
/* x86_pmu.handle_irq definition */
#include "../kernel/cpu/perf_event.h"
/* Shared page between hypervisor and domain */
static DEFINE_PER_CPU(struct xen_pmu_data *, xenpmu_shared);
#define get_xenpmu_data() per_cpu(xenpmu_shared, smp_processor_id())
/* perf callbacks */
static int xen_is_in_guest(void)
{
const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
if (!xenpmu_data) {
pr_warn_once("%s: pmudata not initialized\n", __func__);
return 0;
}
if (!xen_initial_domain() || (xenpmu_data->domain_id >= DOMID_SELF))
return 0;
return 1;
}
static int xen_is_user_mode(void)
{
const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
if (!xenpmu_data) {
pr_warn_once("%s: pmudata not initialized\n", __func__);
return 0;
}
if (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_PV)
return (xenpmu_data->pmu.pmu_flags & PMU_SAMPLE_USER);
else
return !!(xenpmu_data->pmu.r.regs.cpl & 3);
}
static unsigned long xen_get_guest_ip(void)
{
const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
if (!xenpmu_data) {
pr_warn_once("%s: pmudata not initialized\n", __func__);
return 0;
}
return xenpmu_data->pmu.r.regs.ip;
}
static struct perf_guest_info_callbacks xen_guest_cbs = {
.is_in_guest = xen_is_in_guest,
.is_user_mode = xen_is_user_mode,
.get_guest_ip = xen_get_guest_ip,
};
/* Convert registers from Xen's format to Linux' */
static void xen_convert_regs(const struct xen_pmu_regs *xen_regs,
struct pt_regs *regs, uint64_t pmu_flags)
{
regs->ip = xen_regs->ip;
regs->cs = xen_regs->cs;
regs->sp = xen_regs->sp;
if (pmu_flags & PMU_SAMPLE_PV) {
if (pmu_flags & PMU_SAMPLE_USER)
regs->cs |= 3;
else
regs->cs &= ~3;
} else {
if (xen_regs->cpl)
regs->cs |= 3;
else
regs->cs &= ~3;
}
}
irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id)
{
int ret = IRQ_NONE;
struct pt_regs regs;
const struct xen_pmu_data *xenpmu_data = get_xenpmu_data();
if (!xenpmu_data) {
pr_warn_once("%s: pmudata not initialized\n", __func__);
return ret;
}
xen_convert_regs(&xenpmu_data->pmu.r.regs, ®s,
xenpmu_data->pmu.pmu_flags);
if (x86_pmu.handle_irq(®s))
ret = IRQ_HANDLED;
return ret;
}
bool is_xen_pmu(int cpu)
{
return (per_cpu(xenpmu_shared, cpu) != NULL);
}
void xen_pmu_init(int cpu)
{
int err;
struct xen_pmu_params xp;
unsigned long pfn;
struct xen_pmu_data *xenpmu_data;
BUILD_BUG_ON(sizeof(struct xen_pmu_data) > PAGE_SIZE);
if (xen_hvm_domain())
return;
xenpmu_data = (struct xen_pmu_data *)get_zeroed_page(GFP_KERNEL);
if (!xenpmu_data) {
pr_err("VPMU init: No memory\n");
return;
}
pfn = virt_to_pfn(xenpmu_data);
xp.val = pfn_to_mfn(pfn);
xp.vcpu = cpu;
xp.version.maj = XENPMU_VER_MAJ;
xp.version.min = XENPMU_VER_MIN;
err = HYPERVISOR_xenpmu_op(XENPMU_init, &xp);
if (err)
goto fail;
per_cpu(xenpmu_shared, cpu) = xenpmu_data;
if (cpu == 0)
perf_register_guest_info_callbacks(&xen_guest_cbs);
return;
fail:
pr_warn_once("Could not initialize VPMU for cpu %d, error %d\n",
cpu, err);
free_pages((unsigned long)xenpmu_data, 0);
}
void xen_pmu_finish(int cpu)
{
struct xen_pmu_params xp;
if (xen_hvm_domain())
return;
xp.vcpu = cpu;
xp.version.maj = XENPMU_VER_MAJ;
xp.version.min = XENPMU_VER_MIN;
(void)HYPERVISOR_xenpmu_op(XENPMU_finish, &xp);
free_pages((unsigned long)per_cpu(xenpmu_shared, cpu), 0);
per_cpu(xenpmu_shared, cpu) = NULL;
}
|
