> On May 14, 2020, at 1:13 AM, Igor Mammedov <imamm...@redhat.com> wrote: > >> >> >>> Will following hack work for you? >>> possible permutations >>> 1) ACPI hotplug everywhere >>> -global PIIX4_PM.acpi-pci-hotplug=on -global >>> PIIX4_PM.acpi-pci-hotplug-with-bridge-support=on -device >>> pci-bridge,chassis_nr=1,shpc=doesnt_matter -device >>> e1000,bus=pci.1,addr=01,id=netdev1 >>> >>> 2) No hotplug at all >>> -global PIIX4_PM.acpi-pci-hotplug=off -global >>> PIIX4_PM.acpi-pci-hotplug-with-bridge-support=on -device >>> pci-bridge,chassis_nr=1,shpc=off -device e1000,bus=pci.1,addr=01,id=netdev1 >>> >>> -global PIIX4_PM.acpi-pci-hotplug=off -global >>> PIIX4_PM.acpi-pci-hotplug-with-bridge-support=off -device >>> pci-bridge,chassis_nr=1,shpc=doesnt_matter -device >>> e1000,bus=pci.1,addr=01,id=netdev1 >> >> Given that my patch is not acceptable, I’d prefer the following in the order >> of preference: >> >> (a) Have an option to disable hot ejection of PCI-PCI bridge so that Windows >> does not even show this HW in the “safely remove HW” option. If we can do >> this then from OS perspective the GUI options will be same as what is >> available with PCIE/q35 - none of the devices will be hot ejectable if the >> hot plug option is turned off from the PCIE slots where devices are plugged >> into. >> I looked at the code. It seems to manipulate ACPI tables of the empty slots >> of the root bus where no devices are attached (see comment "/* add hotplug >> slots for non present devices */ “). For cold plugged bridges, it recurses >> down to scan the slots of the bridge. Is it possible to disable hot plug for >> the slot to which the bridge is attached? > > I don't think it's possible to have per slot hotplug on conventional PCI > hardware. > it's per bridge property.
We add the AMLs per empty slot though. When the pic bridge is attached, we do nothing, just recurse into the bridge slots. That is what I was asking, if it was possible to just disable the AMLs or use some tricks to say that this particular slot is not hotpluggable. I am not sure why Windows is trying to eject the PCI bridge and failing. Maybe something related to this comment? /* When hotplug for bridges is enabled, bridges are * described in ACPI separately (see build_pci_bus_end). * In this case they aren't themselves hot-pluggable. * Hotplugged bridges *are* hot-pluggable. */ > > >> (b) Failing above, having a global option to disable all hot plug, including >> the 32 slots of the root bus would be good. However, this does not give us >> the flexibility we have with PCIE (that is, to hot plug a device, we can >> always plug it to a slot with hot plug enabled). > > sounds fine to me, at least it will address problem. > Can you post a patch to that effect please? > /It should disable all AML related to hotplug and related hadware code/ I have tried a patch and sent it.