Re: [Qemu-devel] [PATCH v3 3/4] target-ppc: ppc can be either endian

[Peter Maydell]

On 5 May 2014 09:07, Greg Kurz <address@hidden> wrote:
> POWER7, POWER7+ and POWER8 families use the ILE bit of the LPCR
> special purpose register to decide the endianness to use when
> entering interrupt handlers. When running a Linux guest, this
> provides a hint on the endianness used by the kernel. From a
> QEMU point of view, the information is needed for legacy virtio
> support and crash dump support as well.

Do you care about the case of:
 * kernel bigendian
 * userspace littleendian (or vice-versa)
 * guest kernel passes virtio device through to guest userspace
 * guest userspace is doing the manipulation of the device

?

(Will Deacon just suggested this as a possibility on the
kvm-arm mailing list...)

Also, are we documenting what the process should be for a
virtio implementation to decide the endianness for a particular
architecture? I assume we'd like kvmtool and QEMU to do
the same thing rather than subtly different things...

thanks
-- PMM