Re: [libvirt] [PATCH 3/3] qemu: use qemu-xhci USB controller by default for ppc64 and aarch64
On Thu, 2017-04-27 at 10:24 +0200, Pavel Hrdina wrote:
> You're technically correct[1]. However, piix3-uhci is
> another piece of Intel-derived hardware so in practice
> qemu-system-aarch64 is very unlikely to have it compiled
> in and most users will end up getting the error instead.
Isn't the nec-xhci also Intel hardware, so the same would apply to that
controller as well.
Not quite:
Intel Corporation 82371SB PIIX3 USB [Natoma/Triton II] [8086:7020]
NEC Corporation uPD720200 USB 3.0 Host Controller [1033:0194]
The vendor for piix3-uhci is Intel Corporation, the vendor
for nec-xhci is NEC Corporation.
I guess both are unlikely to show up in actual aarch64
hardware, but the former is clearly x86-specific while the
latter is somewhat more architecture-agnostic.
Moreover, this probably happens only for downstream
builds of QEMU (most likely only RHEL/CentOS) as there is no configure
option for that. QEMU has some default configs for different architectures
but in upstream QEMU the set of UHCI usb controllers is enabled by default
for aarch64.
The upstream QEMU configuration takes the kitchen sink
approach, eg. qemu-system-ppc64 will include allwinner-ahci
and other devices that clearly have no place in a ppc64
guest, so I don't think we should take that as an indication
that piix-uhci is something anyone will want to reasonably
use on aarch64 :)
--
Andrea Bolognani / Red Hat / Virtualization