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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Test edge cases and race conditions in kvm_recalculate_apic_map().
*/
#include <sys/ioctl.h>
#include <pthread.h>
#include <time.h>
#include "processor.h"
#include "test_util.h"
#include "kvm_util.h"
#include "apic.h"
#define TIMEOUT 5 /* seconds */
#define LAPIC_DISABLED 0
#define LAPIC_X2APIC (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)
#define MAX_XAPIC_ID 0xff
static void *race(void *arg)
{
struct kvm_lapic_state lapic = {};
struct kvm_vcpu *vcpu = arg;
while (1) {
/* Trigger kvm_recalculate_apic_map(). */
vcpu_ioctl(vcpu, KVM_SET_LAPIC, &lapic);
pthread_testcancel();
}
return NULL;
}
int main(void)
{
struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
struct kvm_vcpu *vcpuN;
struct kvm_vm *vm;
pthread_t thread;
time_t t;
int i;
kvm_static_assert(KVM_MAX_VCPUS > MAX_XAPIC_ID);
/*
* Create the max number of vCPUs supported by selftests so that KVM
* has decent amount of work to do when recalculating the map, i.e. to
* make the problematic window large enough to hit.
*/
vm = vm_create_with_vcpus(KVM_MAX_VCPUS, NULL, vcpus);
/*
* Enable x2APIC on all vCPUs so that KVM doesn't bail from the recalc
* due to vCPUs having aliased xAPIC IDs (truncated to 8 bits).
*/
for (i = 0; i < KVM_MAX_VCPUS; i++)
vcpu_set_msr(vcpus[i], MSR_IA32_APICBASE, LAPIC_X2APIC);
ASSERT_EQ(pthread_create(&thread, NULL, race, vcpus[0]), 0);
vcpuN = vcpus[KVM_MAX_VCPUS - 1];
for (t = time(NULL) + TIMEOUT; time(NULL) < t;) {
vcpu_set_msr(vcpuN, MSR_IA32_APICBASE, LAPIC_X2APIC);
vcpu_set_msr(vcpuN, MSR_IA32_APICBASE, LAPIC_DISABLED);
}
ASSERT_EQ(pthread_cancel(thread), 0);
ASSERT_EQ(pthread_join(thread, NULL), 0);
kvm_vm_free(vm);
return 0;
}
|
