Re: [PATCH] virtio_mmio: expose header to userspace

From: Michael S. Tsirkin
Date: Fri Jan 13 2017 - 08:31:21 EST


On Thu, Jan 12, 2017 at 11:58:22PM -0800, Christoph Hellwig wrote:
> On Thu, Jan 12, 2017 at 11:37:22PM +0200, Michael S. Tsirkin wrote:
> > It's handy for userspace emulators like QEMU.
>
> But it's not actually a userspace API - it's an on the write protocol.

We do this for all other virtio transports, mmio shouldn't be
any different.

> so: NAK.

We'll have to agree to disagree on this one. It's the interface
beween linux and the hypervisor. It isn't any less stable
than the one to userspace, for better or worse kvm
(ab)uses uapi for that. Compare also to include/uapi/linux/kvm_para.h
etc.

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MST