KVM Support?

[Eddie James]

On 07/17/2018 03:56 AM, Avi.Fishman at nuvoton.com wrote:
> Hi Eddie,
>
> 1. Where is the JPEG HW compression is done?

It is done in the AST2500 hardware, there is a video engine that 
captures and compresses the video data from the host. The V4L2 
application reads /dev/video0 (which is created by the driver for that 
video engine) to grab the JPEG, and sends it after that.

> a. Is it in the V4L driver; the V4L reads the frame buffer compress it and send it via read()?
> b. Or the V4L reads the frame buffer send it via read() and another driver compress it for the VNC server?
> 2. Since VNC RFB supports also other compression protocols, can we use other protocol than JPEG? Hextile for example.

Yes, although I had to submit a patch to libvncserver project to be able 
to send JPEGs directly (normally libvncserver can only take RGB 
framebuffer, then compress, then send). It may require similar changes 
to send already-compressed Hextile data.

> 3. Can we see this driver and application code so we can adopt to our HW?

Sure. Everything necessary is here: 
https://gerrit.openbmc-project.xyz/#/c/openbmc/openbmc/+/11500/ The 
linux-aspeed and obmc-ikvm recipes point to the kernel driver additions 
and application, respectively.

I will be sending the driver for RFC to the list soon.

Thanks,
Eddie

>
> Regards,
> Avi
>
>
> -----Original Message-----
> From: Eddie James [mailto:eajames at linux.vnet.ibm.com]
> Sent: Monday, July 16, 2018 6:39 PM
> To: Avi Fishman
> Cc: akashgj91 at gmail.com; OpenBMC Maillist; IV00 Uri Trichter; IS20 Eyal Cohen
> Subject: Re: KVM Support?
>
>
>
> On 07/16/2018 10:01 AM, Avi Fishman wrote:
>> Hi Eddie,
>>
>> Is it based on V4L or also VNC?
>> Does it have HW compression or SW only?
> Hi,
>
> The driver interface is V4L2, though I am just using read() calls rather
> than the streaming interface.
> The network interface is VNC, directly sending JPEGs to the clients
> rather than using the normal VNC framebuffer update methods.
>
> Compression is done in HW, and then decompression at the client. So CPU
> usage on the BMC is kept low, though bandwidth usage is pretty high
> because it sends the whole frame every time. Seems to work with any VNC
> client that supports JPEG compression.
>
> I'm currently working through some input latency problems; seems the
> bandwidth usage for the frames causes huge delays for sending the input
> events from the client to the server. Other than that it's working well.
>
> Thanks,
> Eddie
>
>> Thanks,
>> Avi
>> On Mon, Jul 16, 2018 at 5:03 PM Eddie James <eajames at linux.vnet.ibm.com> wrote:
>>>
>>> On 07/16/2018 01:34 AM, AKASH G J wrote:
>>>> Hi Team,
>>>>
>>>> Please someone share whether Keyboard Video Mouse (KVM) over IP
>>>> implementation available in OpenBMC ?
>>> Hi Akash,
>>>
>>> It's in development... If you want to help, let me know! I'll be
>>> updating the mailing list with drivers, etc, when it's more functional.
>>>
>>> Thanks,
>>> Eddie
>>>
>>>>
>>>> Thanks and Regards,
>>>>
>>>> Akash
>
>
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