APPLIED[M]: [SRU][Mantic][PATCH 0/1] UBUNTU: SAUCE: Add mdev_set_iommu_device() kABI

[Andrea Righi]

On Fri, Sep 15, 2023 at 07:50:41PM +0530, Tarun Gupta wrote:
> BugLink : https://bugs.launchpad.net/bugs/1988806
> 
> SRU Justification:
> 
> [Impact]
> 
> Currently, with below commit present in 5.16 upstream kernel,
> mdev_set_iommu_device() kABI is removed.
> 
>  fda49d97f2c4 ("vfio: remove the unused mdev iommu hook")
> 
> This results in SRIOV based Nvidia vGPU being broken with kernels that
> have the above upstream commit present.
> So, with Ubuntu 22.04 HWE kernel update (i.e the 6.5.x Mantic kernel),
> SRIOV based Nvidia vGPU is broken.
> 
> Earlier, during Kinetic and Lunar release, a similar patch
> was accepted. Refer
> https://lists.ubuntu.com/archives/kernel-team/2022-September/133142.html 
> https://lists.ubuntu.com/archives/kernel-team/2023-May/139578.html
> 
> [Fix]
> 
> On 6.5.x HWE kernel, we revert the above patch which removed the support
> for mdev_set_iommu_device() kABI so that vGPU works fine.
> 
> Separately, to fix this in upstream kernels, vGPU will adopt
> vfio-pci-core framework instead of using MDEV framework.
> In Ubuntu 24.04 LTS onwards, we don't need this custom patch as vGPU
> will use vfio-pci-framework. This should be the last Ubuntu release that
> requires this custom mdev patch.
> 
> [Testcase]
> 
> Run SRIOV based (Ampere+) Nvidia vGPU on 6.5.x (Mantic) kernel.

Applied to mantic/linux.

Thanks,
-Andrea