lkml.org 
[lkml]   [2016]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH V2 2/3] vfio, platform: make reset driver a requirement
From
Date
Hi Sinan,
On 03/13/2016 06:25 PM, Sinan Kaya wrote:
> 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@codeaurora.org>
>> ---
>> 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.
To my knowledge only the PL330 DMA controller (drivers/dma/pl330.c) was
passthrough'ed at some point, rather for development purpose than
production purpose. This was done by Virtual Open Systems (ask Baptiste
for more details). But I don't think this is really used.
>
> Would you include a reset needed flag and just not require it for AMBA?
> (I honestly don't like this idea)
>
I think the requirement also makes sense for AMBA.

Maybe an option would be to add a module parameter that would allow to
use the vfio platform/amba driver without reset module (with explicit
opt-in from the user). Maybe this can be done later on.

FYI I will not have access to my mailbox until the end of the week.

Best Regards

Eric

\
 
 \ /
  Last update: 2016-03-16 06:01    [W:0.097 / U:0.308 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site