The PCI hotplug eject register has always returned 0, so let's redefine
it as a hotplug feature register. The existing model of using separate
up & down read-only registers and an eject via write to this register
becomes the base implementation. As we make use of new interfaces we'll
set bits here to allow the BIOS and AML implementation to optimize for
the platform implementation.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Clarify this register as read-only and remove write code. No
change in existing behavior.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The write side of these registers is never used and actually can't be
used as defined because any read/modify/write sequence from the guest
potentially races with qemu. Drop the write support and define these
as read-only registers.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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>