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May 10, 2020 . 1 changed file with 259 additions and 0 deletions.There are no files selected for viewing
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Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -0,0 +1,259 @@ #define _GNU_SOURCE #include <asm/bootparam.h> #include <errno.h> #include <fcntl.h> #include <linux/kvm.h> #include <linux/kvm_para.h> #include <stdarg.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/stat.h> #include <unistd.h> struct guest { int kvm_fd; int vm_fd; int vcpu_fd; void *mem; }; static int guest_error(struct guest *g, const char *fmt, ...) { va_list args; va_start(args, fmt); vfprintf(stderr, fmt, args); fprintf(stderr, ", errno: %d\n", errno); va_end(args); return -1; } static int guest_init_regs(struct guest *g) { struct kvm_regs regs; struct kvm_sregs sregs; if (ioctl(g->vcpu_fd, KVM_GET_SREGS, &(sregs)) < 0) { return guest_error(g, "failed to get registers"); } sregs.cs.base = 0; sregs.cs.limit = ~0; sregs.cs.g = 1; sregs.ds.base = 0; sregs.ds.limit = ~0; sregs.ds.g = 1; sregs.fs.base = 0; sregs.fs.limit = ~0; sregs.fs.g = 1; sregs.gs.base = 0; sregs.gs.limit = ~0; sregs.gs.g = 1; sregs.es.base = 0; sregs.es.limit = ~0; sregs.es.g = 1; sregs.ss.base = 0; sregs.ss.limit = ~0; sregs.ss.g = 1; sregs.cs.db = 1; sregs.ss.db = 1; sregs.cr0 |= 1; /* enable protected mode */ if (ioctl(g->vcpu_fd, KVM_SET_SREGS, &sregs) < 0) { return guest_error(g, "failed to set special registers"); } if (ioctl(g->vcpu_fd, KVM_GET_REGS, &(regs)) < 0) { return guest_error(g, "failed to get registers"); } regs.rflags = 2; regs.rip = 0x100000; regs.rsi = 0x10000; if (ioctl(g->vcpu_fd, KVM_SET_REGS, &(regs)) < 0) { return guest_error(g, "failed to set registers"); } return 0; } static int guest_init_cpu_id(struct guest *g) { struct { uint32_t nent; uint32_t padding; struct kvm_cpuid_entry2 entries[100]; } kvm_cpuid; kvm_cpuid.nent = sizeof(kvm_cpuid.entries) / sizeof(kvm_cpuid.entries[0]); ioctl(g->kvm_fd, KVM_GET_SUPPORTED_CPUID, &kvm_cpuid); for (unsigned int i = 0; i < kvm_cpuid.nent; i++) { struct kvm_cpuid_entry2 *entry = &kvm_cpuid.entries[i]; if (entry->function == KVM_CPUID_SIGNATURE) { entry->eax = KVM_CPUID_FEATURES; entry->ebx = 0x4b4d564b; // KVMK entry->ecx = 0x564b4d56; // VMKV entry->edx = 0x4d; // M } } ioctl(g->vcpu_fd, KVM_SET_CPUID2, &kvm_cpuid); return 0; } int guest_init(struct guest *g) { if ((g->kvm_fd = open("/dev/kvm", O_RDWR)) < 0) { return guest_error(g, "failed to open /dev/kvm"); } if ((g->vm_fd = ioctl(g->kvm_fd, KVM_CREATE_VM, 0)) < 0) { return guest_error(g, "failed to create vm"); } if (ioctl(g->vm_fd, KVM_SET_TSS_ADDR, 0xffffd000) < 0) { return guest_error(g, "failed to set tss addr"); } __u64 map_addr = 0xffffc000; if (ioctl(g->vm_fd, KVM_SET_IDENTITY_MAP_ADDR, &map_addr) < 0) { return guest_error(g, "failed to set identity map addr"); } if (ioctl(g->vm_fd, KVM_CREATE_IRQCHIP, 0) < 0) { return guest_error(g, "failed to create irq chip"); } struct kvm_pit_config pit = { .flags = 0, }; if (ioctl(g->vm_fd, KVM_CREATE_PIT2, &pit) < 0) { return guest_error(g, "failed to create i8254 interval timer"); } g->mem = mmap(NULL, 1 << 30, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (g->mem == NULL) { return guest_error(g, "failed to mmap vm memory"); } struct kvm_userspace_memory_region region = { .slot = 0, .flags = 0, .guest_phys_addr = 0, .memory_size = 1 << 30, .userspace_addr = (__u64)g->mem, }; if (ioctl(g->vm_fd, KVM_SET_USER_MEMORY_REGION, ®ion) < 0) { return guest_error(g, "failed to set user memory region"); } if ((g->vcpu_fd = ioctl(g->vm_fd, KVM_CREATE_VCPU, 0)) < 0) { return guest_error(g, "failed to create vcpu"); } guest_init_regs(g); guest_init_cpu_id(g); return 0; } int guest_load(struct guest *g, const char *image_path) { size_t datasz; void *data; int fd = open(image_path, O_RDONLY); if (fd < 0) { return 1; } struct stat st; fstat(fd, &st); data = mmap(0, st.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); datasz = st.st_size; close(fd); struct boot_params *boot = (struct boot_params *)(((uint8_t *)g->mem) + 0x10000); void *cmdline = (void *)(((uint8_t *)g->mem) + 0x20000); void *kernel = (void *)(((uint8_t *)g->mem) + 0x100000); memset(boot, 0, sizeof(struct boot_params)); memmove(boot, data, sizeof(struct boot_params)); size_t setup_sectors = boot->hdr.setup_sects; size_t setupsz = (setup_sectors + 1) * 512; boot->hdr.vid_mode = 0xFFFF; // VGA boot->hdr.type_of_loader = 0xFF; boot->hdr.ramdisk_image = 0x0; boot->hdr.ramdisk_size = 0x0; boot->hdr.loadflags |= CAN_USE_HEAP | 0x01 | KEEP_SEGMENTS; boot->hdr.heap_end_ptr = 0xFE00; boot->hdr.ext_loader_ver = 0x0; boot->hdr.cmd_line_ptr = 0x20000; memset(cmdline, 0, boot->hdr.cmdline_size); memcpy(cmdline, "console=ttyS0", 14); memmove(kernel, (char *)data + setupsz, datasz - setupsz); return 0; } void guest_exit(struct guest *g) { close(g->kvm_fd); close(g->vm_fd); close(g->vcpu_fd); munmap(g->mem, 1 << 30); } int guest_run(struct guest *g) { int run_size = ioctl(g->kvm_fd, KVM_GET_VCPU_MMAP_SIZE, 0); struct kvm_run *run = mmap(0, run_size, PROT_READ | PROT_WRITE, MAP_SHARED, g->vcpu_fd, 0); for (;;) { int ret = ioctl(g->vcpu_fd, KVM_RUN, 0); if (ret < 0) { return guest_error(g, "kvm_run failed"); } switch (run->exit_reason) { case KVM_EXIT_IO: if (run->io.port == 0x3f8 && run->io.direction == KVM_EXIT_IO_OUT) { uint32_t size = run->io.size; uint64_t offset = run->io.data_offset; printf("%.*s", size * run->io.count, (char *)run + offset); } else if (run->io.port == 0x3f8 + 5 && run->io.direction == KVM_EXIT_IO_IN) { char *value = (char *)run + run->io.data_offset; *value = 0x20; } break; case KVM_EXIT_SHUTDOWN: printf("shutdown\n"); return 0; default: printf("reason: %d\n", run->exit_reason); return -1; } } } int main(int argc, char *argv[]) { int r; struct guest vm; r = guest_init(&vm); if (r < 0) { fprintf(stderr, "failed to initialize guest vm: %d, errno=%d\n", r, errno); return 1; } r = guest_load(&vm, argv[1]); if (r < 0) { fprintf(stderr, "failed to load guest image: %d, errno=%d\n", r, errno); return 1; } guest_run(&vm); guest_exit(&vm); return 0; } -
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Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -0,0 +1,259 @@ #define _GNU_SOURCE #include <asm/bootparam.h> #include <errno.h> #include <fcntl.h> #include <linux/kvm.h> #include <linux/kvm_para.h> #include <stdarg.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/stat.h> #include <unistd.h> struct guest { int kvm_fd; int vm_fd; int vcpu_fd; void *mem; }; static int guest_error(struct guest *g, const char *fmt, ...) { va_list args; va_start(args, fmt); vfprintf(stderr, fmt, args); fprintf(stderr, ", errno: %d\n", errno); va_end(args); return -1; } static int guest_init_regs(struct guest *g) { struct kvm_regs regs; struct kvm_sregs sregs; if (ioctl(g->vcpu_fd, KVM_GET_SREGS, &(sregs)) < 0) { return guest_error(g, "failed to get registers"); } sregs.cs.base = 0; sregs.cs.limit = ~0; sregs.cs.g = 1; sregs.ds.base = 0; sregs.ds.limit = ~0; sregs.ds.g = 1; sregs.fs.base = 0; sregs.fs.limit = ~0; sregs.fs.g = 1; sregs.gs.base = 0; sregs.gs.limit = ~0; sregs.gs.g = 1; sregs.es.base = 0; sregs.es.limit = ~0; sregs.es.g = 1; sregs.ss.base = 0; sregs.ss.limit = ~0; sregs.ss.g = 1; sregs.cs.db = 1; sregs.ss.db = 1; sregs.cr0 |= 1; /* enable protected mode */ if (ioctl(g->vcpu_fd, KVM_SET_SREGS, &sregs) < 0) { return guest_error(g, "failed to set special registers"); } if (ioctl(g->vcpu_fd, KVM_GET_REGS, &(regs)) < 0) { return guest_error(g, "failed to get registers"); } regs.rflags = 2; regs.rip = 0x100000; regs.rsi = 0x10000; if (ioctl(g->vcpu_fd, KVM_SET_REGS, &(regs)) < 0) { return guest_error(g, "failed to set registers"); } return 0; } static int guest_init_cpu_id(struct guest *g) { struct { uint32_t nent; uint32_t padding; struct kvm_cpuid_entry2 entries[100]; } kvm_cpuid; kvm_cpuid.nent = sizeof(kvm_cpuid.entries) / sizeof(kvm_cpuid.entries[0]); ioctl(g->kvm_fd, KVM_GET_SUPPORTED_CPUID, &kvm_cpuid); for (unsigned int i = 0; i < kvm_cpuid.nent; i++) { struct kvm_cpuid_entry2 *entry = &kvm_cpuid.entries[i]; if (entry->function == KVM_CPUID_SIGNATURE) { entry->eax = KVM_CPUID_FEATURES; entry->ebx = 0x4b4d564b; // KVMK entry->ecx = 0x564b4d56; // VMKV entry->edx = 0x4d; // M } } ioctl(g->vcpu_fd, KVM_SET_CPUID2, &kvm_cpuid); return 0; } int guest_init(struct guest *g) { if ((g->kvm_fd = open("/dev/kvm", O_RDWR)) < 0) { return guest_error(g, "failed to open /dev/kvm"); } if ((g->vm_fd = ioctl(g->kvm_fd, KVM_CREATE_VM, 0)) < 0) { return guest_error(g, "failed to create vm"); } if (ioctl(g->vm_fd, KVM_SET_TSS_ADDR, 0xffffd000) < 0) { return guest_error(g, "failed to set tss addr"); } __u64 map_addr = 0xffffc000; if (ioctl(g->vm_fd, KVM_SET_IDENTITY_MAP_ADDR, &map_addr) < 0) { return guest_error(g, "failed to set identity map addr"); } if (ioctl(g->vm_fd, KVM_CREATE_IRQCHIP, 0) < 0) { return guest_error(g, "failed to create irq chip"); } struct kvm_pit_config pit = { .flags = 0, }; if (ioctl(g->vm_fd, KVM_CREATE_PIT2, &pit) < 0) { return guest_error(g, "failed to create i8254 interval timer"); } g->mem = mmap(NULL, 1 << 30, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (g->mem == NULL) { return guest_error(g, "failed to mmap vm memory"); } struct kvm_userspace_memory_region region = { .slot = 0, .flags = 0, .guest_phys_addr = 0, .memory_size = 1 << 30, .userspace_addr = (__u64)g->mem, }; if (ioctl(g->vm_fd, KVM_SET_USER_MEMORY_REGION, ®ion) < 0) { return guest_error(g, "failed to set user memory region"); } if ((g->vcpu_fd = ioctl(g->vm_fd, KVM_CREATE_VCPU, 0)) < 0) { return guest_error(g, "failed to create vcpu"); } guest_init_regs(g); guest_init_cpu_id(g); return 0; } int guest_load(struct guest *g, const char *image_path) { size_t datasz; void *data; int fd = open(image_path, O_RDONLY); if (fd < 0) { return 1; } struct stat st; fstat(fd, &st); data = mmap(0, st.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); datasz = st.st_size; close(fd); struct boot_params *boot = (struct boot_params *)(((uint8_t *)g->mem) + 0x10000); void *cmdline = (void *)(((uint8_t *)g->mem) + 0x20000); void *kernel = (void *)(((uint8_t *)g->mem) + 0x100000); memset(boot, 0, sizeof(struct boot_params)); memmove(boot, data, sizeof(struct boot_params)); size_t setup_sectors = boot->hdr.setup_sects; size_t setupsz = (setup_sectors + 1) * 512; boot->hdr.vid_mode = 0xFFFF; // VGA boot->hdr.type_of_loader = 0xFF; boot->hdr.ramdisk_image = 0x0; boot->hdr.ramdisk_size = 0x0; boot->hdr.loadflags |= CAN_USE_HEAP | 0x01 | KEEP_SEGMENTS; boot->hdr.heap_end_ptr = 0xFE00; boot->hdr.ext_loader_ver = 0x0; boot->hdr.cmd_line_ptr = 0x20000; memset(cmdline, 0, boot->hdr.cmdline_size); memcpy(cmdline, "console=ttyS0", 14); memmove(kernel, (char *)data + setupsz, datasz - setupsz); return 0; } void guest_exit(struct guest *g) { close(g->kvm_fd); close(g->vm_fd); close(g->vcpu_fd); munmap(g->mem, 1 << 30); } int guest_run(struct guest *g) { int run_size = ioctl(g->kvm_fd, KVM_GET_VCPU_MMAP_SIZE, 0); struct kvm_run *run = mmap(0, run_size, PROT_READ | PROT_WRITE, MAP_SHARED, g->vcpu_fd, 0); for (;;) { int ret = ioctl(g->vcpu_fd, KVM_RUN, 0); if (ret < 0) { return guest_error(g, "kvm_run failed"); } switch (run->exit_reason) { case KVM_EXIT_IO: if (run->io.port == 0x3f8 && run->io.direction == KVM_EXIT_IO_OUT) { uint32_t size = run->io.size; uint64_t offset = run->io.data_offset; printf("%.*s", size * run->io.count, (char *)run + offset); } else if (run->io.port == 0x3f8 + 5 && run->io.direction == KVM_EXIT_IO_IN) { char *value = (char *)run + run->io.data_offset; *value = 0x20; } break; case KVM_EXIT_SHUTDOWN: printf("shutdown\n"); return 0; default: printf("reason: %d\n", run->exit_reason); return -1; } } } int main(int argc, char *argv[]) { int r; struct guest vm; r = guest_init(&vm); if (r < 0) { fprintf(stderr, "failed to initialize guest vm: %d, errno=%d\n", r, errno); return 1; } r = guest_load(&vm, argv[1]); if (r < 0) { fprintf(stderr, "failed to load guest image: %d, errno=%d\n", r, errno); return 1; } guest_run(&vm); guest_exit(&vm); return 0; }