down branch is son(father invokes son)
#############
static struct kvm_x86_ops vmx_x86_ops={} ----> x86/vmx.c
kvm kernel module entry point
Execution path after kvm kernel module being loaded(insmode kvm.ko, kvm_intel.ko).
vmx_init(vmx.c)
|
kvm_init(kvm_main.c)
|
kvm_arch_init(kvm_main.c) --> kvm_arch_hardware_setup
| |
kvm_timer_init(x86.c) kvm_x86_ops->hardware_setup(vmx.c)
|
setup_vmcs_config(vmx.c) --> alloc_kvm_area(vmx.c)
| for_each_cpu
alloc_vmcs_cpu(vmx.c)
kvm kernel module handles KVM_RUN request from userspace:
KVM_RUN ---> kvm_vcpu_ioctl (kvm_main.c)
|
kvm_arch_vcpu_ioctl_run(x86/x86.c)
|
__vcpu_run(x86.c)
|
vcpu_enter_guest
|
kvm_x86_ops->run(vmx_vcpu_run in vmc.c)
Handle guest io instructions:
vcpu_enter_guest
| vmexit
kvm_x86_ops->run ---> kvm_x86_ops->handle_exit(vmx_handle_exit)
|
kvm_vmx_exit_handlers[exit_reason](handle_io in vmc.c)
|
kvm_emulate_pio (x86.c)
|
/ \
return 0 kernel_pio(x86.c) --> complete_io
| |
return (userspace) vcpu_enter_guest
| mode switch@ qemu-kvm
kvm_handle_io (kvm_run() kvm_all.c)
|
ioctl(KVM_RUN)
Allocate and initialize VMCS for a vcpu:
KVM_CREATE_VCPU ---> kvm_vm_ioctl (kvm_main.c)
|
kvm_vm_ioctl_create_vcpu(kvm_main.c)
|
kvm_arch_vcpu_create(x86.c)
|
kvm_x86_ops->vcpu_create(vmx_create_vcpu in vmc.c)
|
alloc_vmcs(vmx.c) ---> vmx_vcpu_setup
| |
alloc_vmcs_cpu(vmx.c) vmcs_writel --> guest_write_tsc
