From 9c046d96d4d0d1fef89a30b1491775492082da9d Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti <mtosatti@redhat.com> Date: Tue, 11 Jan 2011 14:20:38 -0200 Subject: [PATCH] document QEMU<->ACPIBIOS PCI hotplug interface Document how QEMU communicates with ACPI BIOS for PCI hotplug. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- docs/specs/acpi_pci_hotplug.txt | 37 +++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 docs/specs/acpi_pci_hotplug.txt diff --git a/docs/specs/acpi_pci_hotplug.txt b/docs/specs/acpi_pci_hotplug.txt new file mode 100644 index 0000000000..f0f74a7c7c --- /dev/null +++ b/docs/specs/acpi_pci_hotplug.txt @@ -0,0 +1,37 @@ +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. + +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. + +PCI device eject (IO port 0xae08-0xae0b, 4-byte access): +---------------------------------------- + +Used by ACPI BIOS _EJ0 method to request device removal. One bit per slot. +Reads return 0. + +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. -- 2.30.2