APPLIED: [SRU] [F/Unstable] [PATCH 0/1] Add sysfs attribute to show remapped NVMe

[Seth Forshee]

On Mon, Feb 17, 2020 at 10:10:30PM +0800, Kai-Heng Feng wrote:
> BugLink: https://bugs.launchpad.net/bugs/1863621
> 
> [Impact]
> Intel Rapid Storage Technology hides NVMe behind AHCI controller, to
> provide firmware base "fusion drive", like combining with Intel Optane.
> 
> There's a driver to support this but upstream doesn't like it for
> reasons like NVMe quirks can't be applied when NVMe are behind AHCI
> controller.
> 
> So we need to devise a mechanism to ask users to change BIOS storage
> settings. This patch only provides a new attribute to let userspace like
> distro installer know NVMe is remapped behind AHCI.
> 
> [Fix]
> Add a new attribute to show that how many NVMes are remapped.
> 
> [Test]
> After applying the patch, there's a new "remapped_nvme" under the AHCI PCI
> device sysfs.
> 
> If there's no remapped NVMe:
> $ cat remapped_nvme
> 0
> 
> If there are two remapped NVMes:
> $ cat remapped_nvme
> 2
> 
> [Regression Potential]
> Low. It adds a new read only sysfs attribute, no actual functional
> change to the AHCI driver.

Applied to focal/master-next and unstable/master. Hopefully you'll be
able to get this upstream soon. Thanks!