On Thu, Sep 08, 2016 at 08:49:43AM +0200, Ingo Molnar wrote:
>
> * Amit Shah <amit.s...@redhat.com> wrote:
>
> > On (Tue) 30 Aug 2016 [08:04:15], Andy Lutomirski wrote:
> > > virtio_console uses a small DMA buffer for control requests. Move
> > > that buffer into heap memory.
> > >
> > > Doing virtio DMA on the stack is normally okay on non-DMA-API virtio
> > > systems (which is currently most of them), but it breaks completely
> > > if the stack is virtually mapped.
> > >
> > > Tested by typing both directions using picocom aimed at /dev/hvc0.
> > >
> > > Signed-off-by: Andy Lutomirski <l...@kernel.org>
> >
> > Looks fine,
> >
> > Reviewed-by: Amit Shah <amit.s...@redhat.com>
> >
> > > ---
> > >
> > > Hi all-
> > >
> > > This is currently broken in tip:x86/asm. If you (Amit) like this patch,
> > > would it make sense for Ingo to add it to -tip?
> >
> > Yes, I'm fine with that.
>
> Thanks! FYI, this patch now lives as:
>
> 9472fe7040bb ("virtio_console: Stop doing DMA on the stack")
>
> in tip:x86/asm, and is targeted for a v4.9 merge.
>
> Thanks,
>
> Ingo
Thinking about it, maybe we should put it in 4.8
after all, for benefit of systems using DMA API with virtio.
Thoughts?
