Re: FAILED: patch "[PATCH] PCI: hv: Serialize the present and eject work items" failed to apply to 4.9-stable tree

["gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>]

On Sun, Apr 22, 2018 at 01:49:55PM +0000, Dexuan Cui wrote:
> > From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org>
> > Sent: Sunday, April 22, 2018 02:45
> > On Tue, Apr 17, 2018 at 02:06:01AM +0000, Dexuan Cui wrote:
> > > > From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > > > Sent: Monday, April 16, 2018 06:23
> > > >
> > > > Dexuan,
> > > >
> > > > On Mon, Apr 16, 2018 at 12:15:06PM +0200, gregkh@linuxfoundation.org
> > > > wrote:
> > > > >
> > > > > The patch below does not apply to the 4.9-stable tree.
> > > > > If someone wants it applied there, or to any other stable or longterm
> > > > > tree, then please email the backport, including the original git commit
> > > > > id to <stable@vger.kernel.org>.
> > > >
> > > > Please do as Greg asks in order to complete the stable backport you
> > > > have requested.
> > > >
> > > > Lorenzo
> > > >
> > > > > greg k-h
> > >
> > > Hi Greg, Lorenzo,
> > > It turns out that Hyper-V vPCI driver (drivers/pci/host/pci-hyperv.c) in v4.9.y
> > > is broken on latest Hyper-V hosts, because it lacks more fixes, e.g. at least
> > > we must cherry-pick these 2 extra fixes:
> > > 7dcf90e PCI: hv: Use vPCI protocol version 1.2
> > > b1db7e7 PCI: hv: Add vPCI version protocol negotiation
> > >
> > > Otherwise, we always get a "hv_pci ... Request for interrupt failed:
> > 0xc0350005"
> > > error, as reported in
> > https://github.com/Microsoft/azure-linux-kernel/issues/13
> > >
> > > The 2 extra fixes depend on a few more patches, and a manual resolution of
> > > conflicts is required...
> > >
> > > Backporting all the required patches to v4.9 seems too many. IMO we may
> > as
> > > well simply drop this patch ("PCI: hv: Serialize the present and eject work
> > items")
> > > for v4.9 and 4.10, 4.11 and 4.12, which are all broken due to the same
> > reason.
> > >
> > > I can confirm this patch ("PCI: hv: Serialize the present and eject work
> > items")
> > > can be applied cleanly to v4.13+.
> > >
> > > PS, For Hyper-V users that want PCIe-pass-through and NIC SR-IOV on some
> > > certain versions of kernels, they can pick the patches here:
> > >
> > https://github.com/Microsoft/azure-linux-kernel
> This link is just FYI only. I didn't mean to ask you to pick any patch from it. :-)
> 
> > I'm sorry, I'm still totally confused.
> > 
> > What exact git commit ids do you wish to see applied to which stable
> > tree?
> I hope this mainline patch 
> 021ad274d7dc ("PCI: hv: Serialize the present and eject work items")
> can be cherry-pick'd to v4.13.y.

4.13.y has been end-of-life for a very long time now.  So there's
nothing I can do there.

> I have verified this patch is already in v4.14.y, v4.15.y and v4.16.y, and 
> it can be cleanly applied to v4.13.y.

That's because 4.13.y is end-of-life and has not gotten an update for a
very long time.

So there's nothing for me to do now?  Great! :)

greg k-h