------- Comment From [email protected] 2021-01-20 09:51 EDT------- Re: the kernel patch to groovy... My understanding is that the window for both 5.8.y and 5.9.y are already closed since they are not LTS releases... The 5.10 window is still open and will be for a while as the most recent LTS -- the fix is already in 5.10.
The upstream 5.10 fix is very close to fitting on groovy. The significant difference with groovy is that vfio_iommu_type1_get_info does not yet exist, so an identical change has to be made in vfio_iommu_type1_ioctl instead (vfio_iommu_type1_ioctl got turned into a switch statement that calls sub-functions by ccd59dce1a21, so code got moved - 5.4 backport needed further changes, but you can see the same sort of accommodation there). I could provide a patch that does this fitting. Or, it looks like upstream ccd59dce1a21 + 7d6e1329652e fits cleanly on groovy. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1907421 Title: [UBUNTU 21.04] vfio: pass DMA availability information to userspace Status in Ubuntu on IBM z Systems: Confirmed Status in linux package in Ubuntu: Fix Committed Status in linux source package in Focal: Confirmed Status in linux source package in Groovy: Incomplete Status in linux source package in Hirsute: Fix Committed Bug description: Description: vfio: pass DMA availability information to userspace Symptom: vfio-pci device on s390 enters error state Problem: Commit 492855939bdb added a limit to the number of concurrent DMA requests for a vfio container. However, lazy unmapping in s390 can in fact cause quite a large number of outstanding DMA requests to build up prior to being purged, potentially the entire guest DMA space. This results in unexpected errors seen in qemu such as 'VFIO_MAP_DMA failed: No space left on device' Solution: The solution requires a change to both kernel and qemu - For the kernel, add the ability to provide the number of allowable DMA requests via the VFIO_IOMMU_GET_INFO ioctl. Reproduction: Put a vfio-pci device on s390 under I/O load Upstream-ID: a717072007e8aedd3f951726d8cf55454860b30d 7d6e1329652ed971d1b6e0e7bea66fba5044e271 Need also to be integrated into 20.10 and 20.04. OK, just to clarify we don't need to fix bionic for this one, but rather focal (20.04) and groovy (20.10). Furthermore, for 20.04, 20.10 and 21.04 ONLY commit 7d6e1329652ed971d1b6e0e7bea66fba5044e271 is needed, the other was a pre-req that is already present. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1907421/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
