Re: Follow-up on the CXL discussion at OFTC

[Ben Widawsky]

On 21-11-18 15:20:34, Saransh Gupta1 wrote:
> Hi Ben and Jonathan,
> 
> Thanks for your replies. I'm looking forward to the patches.
> 
> For QEMU, I see hotplug support as an item on the list and would like to 
> start working on it. It would be great if you can provide some pointers 
> about how I should go about it.

It's been a while, so I can't recall what's actually missing. I think it should
mostly behave like a normal PCIe endpoint.

> Also, which version of kernel and QEMU (maybe Jonathan's upcoming version) 
> would be a good starting point for it?

If he rebased and claims it works I have no reason to doubt it :-). I have a
small fix on my v4 branch if you want to use the latest port patches.

> 
> Thanks,
> Saransh
> 
> 
> 
> From:   "Jonathan Cameron" <Jonathan.Cameron@Huawei.com>
> To:     "Ben Widawsky" <ben.widawsky@intel.com>
> Cc:     "Saransh Gupta1" <saransh@ibm.com>, <linux-cxl@vger.kernel.org>, 
> <qemu-devel@nongnu.org>
> Date:   11/17/2021 09:32 AM
> Subject:        [EXTERNAL] Re: Follow-up on the CXL discussion at OFTC
> 
> 
> 
> On Wed, 17 Nov 2021 08:57:19 -0800
> Ben Widawsky <ben.widawsky@intel.com> wrote:
> 
> > Hi Saransh. Please add the list for these kind of questions. I've 
> converted your
> > HTML mail, but going forward, the list will eat it, so please use text 
> only.
> > 
> > On 21-11-16 00:14:33, Saransh Gupta1 wrote:
> > >    Hi Ben,
> > > 
> > >    This is Saransh from IBM. Sorry to have (unintentionally) dropped 
> out
> > >    of the conversion on OFTC, I'm new to IRC.
> > >    Just wanted to follow-up on the discussion there. We discussed 
> about
> > >    helping with linux patches reviews. On that front, I have 
> identified
> > >    some colleague(s) who can help me with this. Let me know if/how you
> > >    want to proceed with that. 
> > 
> > Currently the ball is in my court to re-roll the RFC v2 patches [1] 
> based on
> > feedback from Dan. I've implemented all/most of it, but I'm still 
> debugging some
> > issues with the result.
> > 
> > > 
> > >    Maybe not urgently, but my team would also like to get an 
> understanding
> > >    of the missing pieces in QEMU. Initially our focus is on type3 
> memory
> > >    access and hotplug support. Most of the work that my team does is
> > >    open-source, so contributing to the QEMU effort is another possible
> > >    line of collaboration. 
> > 
> > If you haven't seen it already, check out my LPC talk [2]. The QEMU 
> patches
> > could use a lot of love. Mostly, I have little/no motivation until 
> upstream
> > shows an interest because I don't have time currently to make sure I 
> don't break
> > vs. upstream. If you want more details here, I can provide them, and I 
> will Cc
> > the qemu-devel mailing list; the end of the LPC talk [2] does have a 
> list.
> Hi Ben, Saransh
> 
> I have a forward port of the series + DOE etc to near current QEMU that is 
> lightly tested,
> and can look to push that out publicly later this week.
> 
> I'd also like to push QEMU support forwards and to start getting this 
> upstream in QEMU
> + fill in some of the missing parts.
> 
> Was aiming to make progress on this a few weeks ago, but as ever other 
> stuff
> got in the way.
> 
> +CC qemu-devel in case anyone else also looking at this.
> 
> Jonathan
> 
> 
> 
> > 
> > > 
> > >    Thanks for your help and guidance!
> > > 
> > >    Best,
> > >    Saransh Gupta
> > >    Research Staff Member, IBM Research 
> > 
> > [1]: 
> https://lore.kernel.org/linux-cxl/20211022183709.1199701-1-ben.widawsky@intel.com/T/#t
>  
> 
> > [2]: 
> https://www.youtube.com/watch?v=g89SLjt5Bd4&list=PLVsQ_xZBEyN3wA8Ej4BUjudXFbXuxhnfc&index=49
>  
> 
> 
> 
> 
> 
>