QEMU supports PCI hotplug via ACPI, for PCI bus 0. This document describes the interface between QEMU and the ACPI BIOS.
Generic ACPI GPE block. Bit 1 (GPE.1) used to notify PCI hotplug/eject event to ACPI BIOS, via SCI interrupt.
Slot injection notification pending. One bit per slot.
Read by ACPI BIOS GPE.1 handler to notify OS of injection events. Read-only.
Slot removal notification pending. One bit per slot.
Read by ACPI BIOS GPE.1 handler to notify OS of removal events. Read-only.
Write: Used by ACPI BIOS _EJ0 method to request device removal. One bit per slot.
Read: Hotplug features register. Used by platform to identify features available. Current base feature set (no bits set):
- Read-only "up" register @0xae00, 4-byte access, bit per slot
- Read-only "down" register @0xae04, 4-byte access, bit per slot
- Read/write "eject" register @0xae08, 4-byte access, write: bit per slot eject, read: hotplug feature set
- Read-only hotplug capable register @0xae0c, 4-byte access, bit per slot
Used by ACPI BIOS _RMV method to indicate removability status to OS. One bit per slot. Read-only.