Re: [Qemu-devel] [PATCH v3] Hvmloader: Modify ACPI to only supply _EJ0 methods for PCIslots that support hotplug by runtime patching

[Gonglei (Arei)]

Hi,

> >> In Xen platform, after using upstream qemu, the all of pci devices will 
> >> show
> >> hotplug in the windows guest. In this situation, the windows guest may
> occur
> >> blue screen when VM' user click the icon of VGA card for trying unplug VGA
> >> card.
> >> However, we don't hope VM's user can do such dangerous operation, and
> >> showing
> >> all pci devices inside the guest OS is unfriendly.
> >>
> >> This is done by runtime patching:
> >>    - Rename _EJ0 methods for PCI slots in DSDT to EJ0_:note that this has
> the
> >>      same checksum, but is ignored by OSPM.
> >>    - At compile time, look for these methods in ASL source,find the
> matching
> >> AML,
> >>      and store the offsets of these methods in a table named
> aml_ej0_data.
> >>    - At run time, go over aml_ej0_data, check which slots not support
> hotplug
> >> and
> >>      patch the ACPI table, replacing _EJ0 with EJ0_.
> >>
> >> Signed-off-by: Gaowei <address@hidden>
> >> Signed-off-by: Gonglei <address@hidden>
> 
> Tested-by: Fabio Fantoni <address@hidden>
> 
> Thanks for this very useful patch that avoid that unaware users or as
> mistake make windows domUs unusable.
> 
Thanks.

> I tried to quickly look at the patch to understand how to add some
> optional components, for example on my case the pv drivers, the audio
> card and the spice guest tools (see attachment) but I don't understand
> how to do it.
> Can someone give me some advices about it please?
> 
Maybe you can hard code at libxl__build_device_model_args_new() 
in tools/libxl/libxl_dm.c


Best regards,
-Gonglei