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