xref: /kvmtool/kvm.c (revision 2b0e334253c2d470d9666fc782111b253019e6e4)
1b8f6afcdSPekka Enberg #include "kvm/cpu.h"
2b8f6afcdSPekka Enberg 
36c7d8514SPekka Enberg #include <linux/kvm.h>
42da26a59SPekka Enberg #include <stdbool.h>
5b8f6afcdSPekka Enberg #include <stdlib.h>
6b8f6afcdSPekka Enberg #include <fcntl.h>
7b8f6afcdSPekka Enberg 
89b1fb1c3SPekka Enberg struct kvm {
99b1fb1c3SPekka Enberg 	int			fd;		/* /dev/kvm */
109b1fb1c3SPekka Enberg 	int			vmfd;
11*2b0e3342SPekka Enberg 	int			vcpu_fd;
129b1fb1c3SPekka Enberg };
139b1fb1c3SPekka Enberg 
14b8f6afcdSPekka Enberg static void die(const char *s)
15b8f6afcdSPekka Enberg {
16b8f6afcdSPekka Enberg 	perror(s);
17b8f6afcdSPekka Enberg 	exit(1);
18b8f6afcdSPekka Enberg }
19b8f6afcdSPekka Enberg 
20b8f6afcdSPekka Enberg static void cpu__reset(struct cpu *self)
21b8f6afcdSPekka Enberg {
22b8f6afcdSPekka Enberg 	self->regs.eip		= 0x000fff0UL;
23b8f6afcdSPekka Enberg 	self->regs.eflags	= 0x0000002UL;
24b8f6afcdSPekka Enberg }
25b8f6afcdSPekka Enberg 
26b8f6afcdSPekka Enberg static struct cpu *cpu__new(void)
27b8f6afcdSPekka Enberg {
28b8f6afcdSPekka Enberg 	return calloc(1, sizeof(struct cpu));
29b8f6afcdSPekka Enberg }
30b8f6afcdSPekka Enberg 
314076b041SPekka Enberg static inline bool kvm__supports_extension(struct kvm *self, unsigned int extension)
32b8f6afcdSPekka Enberg {
3328fa19c0SPekka Enberg 	int ret;
34b8f6afcdSPekka Enberg 
354076b041SPekka Enberg 	ret = ioctl(self->fd, KVM_CHECK_EXTENSION, extension);
364076b041SPekka Enberg 	if (ret < 0)
374076b041SPekka Enberg 		return false;
384076b041SPekka Enberg 
394076b041SPekka Enberg 	return ret;
404076b041SPekka Enberg }
414076b041SPekka Enberg 
424076b041SPekka Enberg static struct kvm *kvm__new(void)
434076b041SPekka Enberg {
444076b041SPekka Enberg 	struct kvm *self = calloc(1, sizeof *self);
454076b041SPekka Enberg 
464076b041SPekka Enberg 	if (!self)
474076b041SPekka Enberg 		die("out of memory");
484076b041SPekka Enberg 
494076b041SPekka Enberg 	return self;
504076b041SPekka Enberg }
514076b041SPekka Enberg 
524076b041SPekka Enberg static struct kvm *kvm__init(void)
534076b041SPekka Enberg {
54*2b0e3342SPekka Enberg 	struct kvm_userspace_memory_region mem;
554076b041SPekka Enberg 	struct kvm *self;
564076b041SPekka Enberg 	int ret;
574076b041SPekka Enberg 
584076b041SPekka Enberg 	self = kvm__new();
594076b041SPekka Enberg 
604076b041SPekka Enberg 	self->fd = open("/dev/kvm", O_RDWR);
614076b041SPekka Enberg 	if (self->fd < 0)
62b8f6afcdSPekka Enberg 		die("open");
63b8f6afcdSPekka Enberg 
644076b041SPekka Enberg 	ret = ioctl(self->fd, KVM_GET_API_VERSION, 0);
656c7d8514SPekka Enberg 	if (ret != KVM_API_VERSION)
666c7d8514SPekka Enberg 		die("ioctl");
676c7d8514SPekka Enberg 
684076b041SPekka Enberg 	self->vmfd = ioctl(self->fd, KVM_CREATE_VM, 0);
694076b041SPekka Enberg 	if (self->vmfd < 0)
7028fa19c0SPekka Enberg 		die("open");
7128fa19c0SPekka Enberg 
724076b041SPekka Enberg 	if (!kvm__supports_extension(self, KVM_CAP_USER_MEMORY))
732da26a59SPekka Enberg 		die("KVM_CAP_USER_MEMORY");
742da26a59SPekka Enberg 
75*2b0e3342SPekka Enberg 	mem = (struct kvm_userspace_memory_region) {
76*2b0e3342SPekka Enberg 		.slot			= 0,
77*2b0e3342SPekka Enberg 		.guest_phys_addr	= 0x0UL,
78*2b0e3342SPekka Enberg 		.memory_size		= 64UL * 1024UL * 1024UL,
79*2b0e3342SPekka Enberg 	};
80*2b0e3342SPekka Enberg 
81*2b0e3342SPekka Enberg 	ret = ioctl(self->vmfd, KVM_SET_USER_MEMORY_REGION, &mem, 1);
82*2b0e3342SPekka Enberg 	if (ret < 0)
83*2b0e3342SPekka Enberg 		die("ioctl(KVM_SET_USER_MEMORY_REGION)");
84*2b0e3342SPekka Enberg 
85*2b0e3342SPekka Enberg 	self->vcpu_fd = ioctl(self->vmfd, KVM_CREATE_VCPU, 0);
86*2b0e3342SPekka Enberg 	if (self->vcpu_fd < 0)
87*2b0e3342SPekka Enberg 		die("ioctl(KVM_CREATE_VCPU)");
88*2b0e3342SPekka Enberg 
894076b041SPekka Enberg 	return self;
904076b041SPekka Enberg }
914076b041SPekka Enberg 
92*2b0e3342SPekka Enberg static void kvm__run(struct kvm *self)
93*2b0e3342SPekka Enberg {
94*2b0e3342SPekka Enberg 	int ret;
95*2b0e3342SPekka Enberg 
96*2b0e3342SPekka Enberg 	ret = ioctl(self->vcpu_fd, KVM_RUN, 0);
97*2b0e3342SPekka Enberg 	if (ret < 0)
98*2b0e3342SPekka Enberg 		die("KVM_RUN");
99*2b0e3342SPekka Enberg }
100*2b0e3342SPekka Enberg 
1014076b041SPekka Enberg int main(int argc, char *argv[])
1024076b041SPekka Enberg {
1034076b041SPekka Enberg 	struct cpu *cpu;
1044076b041SPekka Enberg 	struct kvm *kvm;
1054076b041SPekka Enberg 	int ret;
1064076b041SPekka Enberg 
1074076b041SPekka Enberg 	kvm = kvm__init();
1084076b041SPekka Enberg 
109b8f6afcdSPekka Enberg 	cpu = cpu__new();
110b8f6afcdSPekka Enberg 
111b8f6afcdSPekka Enberg 	cpu__reset(cpu);
112b8f6afcdSPekka Enberg 
113*2b0e3342SPekka Enberg 	kvm__run(kvm);
114*2b0e3342SPekka Enberg 
115b8f6afcdSPekka Enberg 	return 0;
116b8f6afcdSPekka Enberg }
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