On Tue, 4 May 2021 15:00:39 +0200 Christoph Hellwig hch@lst.de wrote:

On Tue, May 04, 2021 at 02:59:07PM +0200, Greg Kroah-Hartman wrote:

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Hi Christoph,

FYI, these uapi changes break build of QEMU.

What uapi changes?

What exactly breaks?

Why does QEMU require kernel driver stuff?

Looks like it pull in the uapi struct definitions unconditionally instead of having a local copy. We could fix that by just putting them back, but to me this seems like a rather broken configuration in qemu when it pulls in headers from the running/installed kernel without any feature checks before using them.

It is not pulling them from the installed kernel, but from a development version to get new definitions. Removing things in the kernel requires workarounds in QEMU until it can remove those things as well. It is not a dumb update...