QEMU HPET (High Precision Event Timer) is a feature of the QEMU emulator that provides a high-resolution timer for use by guest operating systems. It allows virtual machines to achieve better accuracy and precision in timing sensitive applications, such as audio and video playback, network traffic analysis, and performance profiling.
The HPET timer uses a 64-bit counter that can run at a frequency of up to 14.3 MHz, allowing for precise measurement of time intervals down to nanoseconds. It also supports multiple timers, which can be used for different purposes, such as measuring CPU usage or scheduling tasks.
To enable HPET in QEMU, the -hpet option can be used when starting the virtual machine. The guest operating system must have support for HPET in order to take advantage of this feature. Some older operating systems may not support HPET, and may require a different timer mechanism to be used.