# Re: \[PATCH\] virtio-console: avoid DMA from vmalloc area

- From: Arnd Bergmann \<arnd@arndb.de\>
- Date: 2021-07-28 09:01:37 
- List: virtualization
- Page: https://ratatoskr.run/virtualization/2021/07/1460537
- Thread: https://ratatoskr.run/linuxppc-dev/2021/07/1460537/t.md

```text
On Wed, Jul 28, 2021 at 10:28 AM Xianting Tian
[ref] wrote:
> 在 2021/7/28 下午3:25, Arnd Bergmann 写道:
>
> I checked several hvc backends, like drivers/tty/hvc/hvc_riscv_sbi.c,
> drivers/tty/hvc/hvc_iucv.c, drivers/tty/hvc/hvc_rtas.c, they don't use dma.
>
> I not finished all hvc backends check yet. But I think even if all hvc
> backends don't use dma currently, it is still possible that the hvc
> backend using dma will be added in the furture.
>
> So I agree with you it should better be fixed in the hvc framework,
> solve the issue in the first place.

Ok, sounds good to me, no need to check more backends then.
I see the hvc-console driver is listed as 'Odd Fixes' in the maintainer
list, with nobody assigned other than the ppc kernel list (added to Cc).

Once you come up with a fix in hvc_console.c, please send that to the
tty maintainers, the ppc list and me, and I'll review it.

        Arnd
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```