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Diffstat (limited to 'src/docs/specs/acpi_pci_hotplug.txt')
| -rw-r--r-- | src/docs/specs/acpi_pci_hotplug.txt | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/docs/specs/acpi_pci_hotplug.txt b/src/docs/specs/acpi_pci_hotplug.txt new file mode 100644 index 0000000..a839434 --- /dev/null +++ b/src/docs/specs/acpi_pci_hotplug.txt @@ -0,0 +1,45 @@ +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 |
