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| author |   Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com> | 2023-10-10 11:40:56 +0000 |
|---|---|---|
| committer | Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com> | 2023-10-10 11:40:56 +0000 |
| commit | e02cda008591317b1625707ff8e115a4841aa889 (patch) | |
| tree | aee302e3cf8b59ec2d32ec481be3d1afddfc8968 /docs/specs/acpi_pci_hotplug.rst | |
| parent | cc668e6b7e0ffd8c9d130513d12053cf5eda1d3b (diff) | |
Introduce Virtio-loopback epsilon release:
Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.
Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9
Diffstat (limited to 'docs/specs/acpi_pci_hotplug.rst')
| -rw-r--r-- | docs/specs/acpi_pci_hotplug.rst | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/docs/specs/acpi_pci_hotplug.rst b/docs/specs/acpi_pci_hotplug.rst new file mode 100644 index 000000000..685bc5c32 --- /dev/null +++ b/docs/specs/acpi_pci_hotplug.rst @@ -0,0 +1,48 @@ +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. |