Re: [PATCH V2 2/3] vfio, platform: make reset driver a requirement

From: Sinan Kaya
Date: Sun Mar 13 2016 - 13:25:26 EST


On 3/11/2016 11:54 AM, Sinan Kaya wrote:
> The code was allowing platform devices to be used without a supporting VFIO
> reset driver. The hardware can be left in some inconsistent state after a
> guest machine abort.
>
> The reset driver will put the hardware back to safe state and disable
> interrupts before returning the control back to the host machine.
>
> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> ---
> drivers/vfio/platform/vfio_platform_common.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
I was looking at the code. It looks like this is going to break VFIO AMBA. The
common implementation is shared with AMBA and platform devices.

I couldn't see a reset function for AMBA devices.

Is there anyway to write reset function for it? I have no experience with
AMBA devices.

Would you include a reset needed flag and just not require it for AMBA?
(I honestly don't like this idea)

--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project