Re: [PATCH] hw/ide: Fix crash when plugging a piix3-ide device into the x-remote machine

[Stefan Hajnoczi <stefanha@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 966 bytes --]

On Tue, Jul 06, 2021 at 10:37:03AM +0200, Philippe Mathieu-Daudé wrote:
> Stefan, IIRC the multi-process conclusion was we have to reject
> PCI devices briding another (non-PCI) bus, such ISA / I2C / USB
> / SD / ... because QEMU register the bus type globally and the
> command line machinery resolves it to plug user-creatable devices,
> so we can not share such buses. Is that correct?

I'm not sure I understand, but I'll try:

You can implement an out-of-process USB host controller (a PCI device),
but QEMU will not be aware of devices on this out-of-process USB bus.

If you're referring to a PCI IDE controller that is also exposed on the
ISA bus, then that's hard to do. Maybe there would need to be a separate
ISA-to-PCI bridge device so there's a clean separation between the PCI
device and the ISA portion. The current multi-process QEMU protocol (and
the upcoming vfio-user protocol) support PCI devices but not ISA
devices.

Stefan

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]