| QEMU<->ACPI BIOS PCI hotplug interface | |
| ====================================== | |
| QEMU supports PCI hotplug via ACPI, for PCI bus 0. This document | |
| describes the interface between QEMU and the ACPI BIOS. | |
| ACPI GPE block (IO ports 0xafe0-0xafe3, byte access) | |
| ---------------------------------------------------- | |
| Generic ACPI GPE block. Bit 1 (GPE.1) used to notify PCI hotplug/eject | |
| event to ACPI BIOS, via SCI interrupt. | |
| PCI slot injection notification pending (IO port 0xae00-0xae03, 4-byte access) | |
| ------------------------------------------------------------------------------ | |
| Slot injection notification pending. One bit per slot. | |
| Read by ACPI BIOS GPE.1 handler to notify OS of injection | |
| events. Read-only. | |
| PCI slot removal notification (IO port 0xae04-0xae07, 4-byte access) | |
| -------------------------------------------------------------------- | |
| Slot removal notification pending. One bit per slot. | |
| Read by ACPI BIOS GPE.1 handler to notify OS of removal | |
| events. Read-only. | |
| PCI device eject (IO port 0xae08-0xae0b, 4-byte access) | |
| ------------------------------------------------------- | |
| 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 | |
| PCI removability status (IO port 0xae0c-0xae0f, 4-byte access) | |
| -------------------------------------------------------------- | |
| Used by ACPI BIOS _RMV method to indicate removability status to OS. One | |
| bit per slot. Read-only. |