Marcel Apfelbaum <address@hidden> writes:
On 11/16/2015 12:11 PM, Paolo Bonzini wrote:
On 16/11/2015 11:10, Marcel Apfelbaum wrote:
What would you lose? Hotplug?
Without the bridge? Yes. However the user can add it manually the
pci-bridge and have it anyway.
Ok, I guess that's more or less acceptable. It's still ugly however, to
the point that I wonder if we should rename the device and call the old
one a failed experiment.
I guess we can rename the pxb to extra-root or something, but in this way
will have a deprecated/duplicated device to support and kill in the future.
Why not use the compat property as it is?
Again, the command line *remains* the same, the difference is where the
devices associated with the pxb will land: on the secondary bus (for QEMU < 2.5)
or on the root bus itself (QEMU >= 2.5).
I know is guest visible, but the guest will see one of them depending
on the machine type.
Regarding the splitting of pxb into 2 devices (pci/pcie), I have
nothing against it,
but because the implementation is *exactly* the same I think we should gain more
by maintaining one device.
I have no opinion on two devices vs. one device + property in this
particular case, I just want to interject that I'd expect the difference
in maintaince to be negligible.
A second device basically takes a copy of the TypeInfo with some
(trivial) init function to make it different. Might be a few more lines
of code than adding a property, but in complexity, it's a wash.
In case you plan to get rid of the old variant: with two devices, you
deprecate and later delete the old device. With device + property, you
deprecate setting the property, and later delete it. The former might
be a bit easier to document.