Re: [PATCH 0/4] ICH9 root PCI hotplug

[Michael S. Tsirkin]

On Fri, Nov 24, 2023 at 03:01:35PM +0100, Igor Mammedov wrote:
> On Wed, 15 Nov 2023 17:18:53 +0000
> Thierry Escande <thierry.escande@vates.tech> wrote:
> 
> > Hi,
> > 
> > This series fixes acpi_hotplug_bridge accessor names, adds new accessors
> > for acpi-root-pci-hotplug property, and enables root PCI hotplug by
> > default for Q35 machine.
> 
> hotplug on Q35 hostbridge is not implemented intentionally
> to keep machine close to the real world.

> PCIe spec 3.1a, 1.3.2.3. Root Complex Integrated Endpoint Rules
> "
> A Root Complex Integrated Endpoint may not be hot-plugged independent of the 
> Root
> Complex as a whole.
> "
> )

To be more precise close to native hotplug.
But we used ACPI for several years now and it seems to be fine.
Maybe it's time we lifted the limitation?


> 
> PS:
> but patch 1/4 is good cleanup, pls include Reviewed-by's and resend it
> as a separate patch after 8.2 has been released (so it wouldn't get lost in 
> the traffic).
> 
> > 
> > Thierry Escande (4):
> >   ich9: Remove unused hotplug field from ICH9LPCPMRegs struct
> >   ich9: Renamed use_acpi_hotplug_bridge accessors
> >   ich9: Add accessors for acpi-root-pci-hotplug
> >   ich9: Enable root PCI hotplug by default
> > 
> >  hw/acpi/ich9.c         | 23 +++++++++++++++++++++--
> >  include/hw/acpi/ich9.h |  1 -
> >  2 files changed, 21 insertions(+), 3 deletions(-)
> >