Tag
virtualization-overhead
- Sep 8, 2026 Virtualized Performance Counters and the Time They Do Not Count How a guest gets access to a PMU, what context switching the counters costs, and why the cycles reported inside a guest systematically omit the time the hypervisor spent on its behalf. virtualization
- Aug 7, 2026 Anatomy of a VM Exit: State Save, Exit Qualification, and Where the Cycles Go What the processor writes to the VMCS on every exit, which exit reasons dominate a running guest, and why the host-side handler usually costs more than the transition itself. virtualization
- Jul 23, 2026 Virtualizing the Local APIC: Access Pages, Virtual Interrupt Delivery, and Posted Interrupts Why every interrupt acknowledgement used to cost an exit, how hardware removed the exit for the common case, and what a posted interrupt descriptor does between the device and the guest. virtualization
- Jun 4, 2025 Emulated MMIO: Instruction Decode, Register Semantics, and Exit Storms How a write to an emulated device register becomes a trap, what the hypervisor must decode before it can act, and why a driver that pokes registers in a loop degrades an entire host. virtualization
- Jan 3, 2025 Nested Paging: The Two-Dimensional Walk and the Cost of a Single Guest Access How EPT and NPT turn every guest memory access into two page walks, what an EPT violation reports, and why the hardware page-walk cache decides whether nested paging is cheap or ruinous. virtualization