IRQFD¶
IRQFD: eventfd handled at kernel, kernel use wait_queue and kvm_set_irq() to inject IRQ to VM.
APIs:
- KVM VM ioctl - KVM_IRQFD
- KVM VM ioctl - KVM_IOEVENTFD
- QEMU kvm-all.c - kvm_irqchip_assign_irqfd()
- QEMU kvm-all.c - kvm_set_ioeventfd_mmio()
- QEMU kvm-all.c - kvm_set_ioeventfd_pio()
source analysis¶
kvm_arch_set_irq_inatomic()
// workqueue
work_struct
INIT_WORK()
schedule_work()
flush_work()
queue_work()
// wait queue
wait_queue_t
init_waitqueue_func_entry()
eventfd_ctx_remove_wait_queue()
wait queue: irqfd_wakeup()
POLLIN: run workqueue irqfd->inject POLLHUP: irqfd_deactivate()
work queue: irqfd_inject()
kvm_set_irq() IRQ resampler
work queue: irqfd_shutdown()
remove evenfd from wait_queue flush_work() irqfd->inject