[Qemu-devel] NVME: is there any plan to support SGL data transfer?

[Qemu-devel] NVME: is there any plan to support SGL data transfer?

[Qu Wenruo]

Hi,

When going through NVMe specification and hw/block/nvme.c,
I found that it seems that NVMe qemu implementation only support PRP for 
sq entry.
And NvmeRwCmd doesn't even use union to define DPTR, but just prp1 and prp2.

Although I am just a newbie, but I'm quite interested in NVMe and want 
to try to implement SGL support for qemu NVMe.

Is there anyone already doing such work? Or is there any plan on 
implement such feature?

Thanks,
Qu

Re: [Qemu-devel] [Qemu-block] NVME: is there any plan to support SGL data transfer?

[Kevin Wolf]

Am 02.06.2017 um 03:47 hat Qu Wenruo geschrieben:
> When going through NVMe specification and hw/block/nvme.c,
> I found that it seems that NVMe qemu implementation only support PRP
> for sq entry.
> And NvmeRwCmd doesn't even use union to define DPTR, but just prp1 and prp2.
> 
> Although I am just a newbie, but I'm quite interested in NVMe and
> want to try to implement SGL support for qemu NVMe.
> 
> Is there anyone already doing such work? Or is there any plan on
> implement such feature?

Keith, you can probably answer this?

Kevin

Re: [Qemu-devel] [Qemu-block] NVME: is there any plan to support SGL data transfer?

[Keith Busch]

On Fri, Jun 02, 2017 at 03:51:51PM +0200, Kevin Wolf wrote:
> Am 02.06.2017 um 03:47 hat Qu Wenruo geschrieben:
> > When going through NVMe specification and hw/block/nvme.c,
> > I found that it seems that NVMe qemu implementation only support PRP
> > for sq entry.
> > And NvmeRwCmd doesn't even use union to define DPTR, but just prp1 and prp2.
> > 
> > Although I am just a newbie, but I'm quite interested in NVMe and
> > want to try to implement SGL support for qemu NVMe.
> > 
> > Is there anyone already doing such work? Or is there any plan on
> > implement such feature?
> 
> Keith, you can probably answer this?

Hi,

I personally have no plans to implement it, but would be happy to see it
added if someone wants to send the patch for review.

Thanks,
Keith

Re: [Qemu-devel] [Qemu-block] NVME: is there any plan to support SGL data transfer?

[Qu Wenruo]

At 06/12/2017 10:05 PM, Keith Busch wrote:
> On Fri, Jun 02, 2017 at 03:51:51PM +0200, Kevin Wolf wrote:
>> Am 02.06.2017 um 03:47 hat Qu Wenruo geschrieben:
>>> When going through NVMe specification and hw/block/nvme.c,
>>> I found that it seems that NVMe qemu implementation only support PRP
>>> for sq entry.
>>> And NvmeRwCmd doesn't even use union to define DPTR, but just prp1 and prp2.
>>>
>>> Although I am just a newbie, but I'm quite interested in NVMe and
>>> want to try to implement SGL support for qemu NVMe.
>>>
>>> Is there anyone already doing such work? Or is there any plan on
>>> implement such feature?
>>
>> Keith, you can probably answer this?
> 
> Hi,
> 
> I personally have no plans to implement it, but would be happy to see it
> added if someone wants to send the patch for review.

Glad to hear that.

I have submitted some preparation patch to update nvme.h for SGL and 
added needed error code for it.

It would be very nice if anyone could review it.

Thanks,
Qu

> 
> Thanks,
> Keith
> 
> 

Re: [Qemu-devel] [Qemu-block] NVME: is there any plan to support SGL data transfer?

[Qu Wenruo]

At 06/12/2017 10:05 PM, Keith Busch wrote:
> On Fri, Jun 02, 2017 at 03:51:51PM +0200, Kevin Wolf wrote:
>> Am 02.06.2017 um 03:47 hat Qu Wenruo geschrieben:
>>> When going through NVMe specification and hw/block/nvme.c,
>>> I found that it seems that NVMe qemu implementation only support PRP
>>> for sq entry.
>>> And NvmeRwCmd doesn't even use union to define DPTR, but just prp1 and prp2.
>>>
>>> Although I am just a newbie, but I'm quite interested in NVMe and
>>> want to try to implement SGL support for qemu NVMe.
>>>
>>> Is there anyone already doing such work? Or is there any plan on
>>> implement such feature?
>>
>> Keith, you can probably answer this?
> 
> Hi,
> 
> I personally have no plans to implement it, but would be happy to see it
> added if someone wants to send the patch for review.

Glad to hear that.

I have already submitted preparation patch to update nvme.h for SGL 
structures and introduced needed error code according to NVMe 1.3 spec.

It would be quite nice if anyone is interested in that patchset.

Thanks,
Qu

> 
> Thanks,
> Keith
> 
>