Thx Matthew for the quick test. I've now submitted the kernel SRU for the remaining fix for focal: https://lists.ubuntu.com/archives/kernel-team/2020-December/thread.html#115495 and changed the status to 'In Progress' for focal.
-- 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/1907265 Title: [UBUNTU 21.04] s390/pci: vfio-pci mmio being disabled erroneously Status in Ubuntu on IBM z Systems: In Progress Status in linux package in Ubuntu: In Progress Status in linux source package in Focal: In Progress Status in linux source package in Groovy: Fix Released Status in linux source package in Hirsute: In Progress Bug description: Description: s390/pci: vfio-pci mmio being disabled erroneously Symptom: PCI virtual functions passed through via vfio-pci are unusable Problem: The fix for CVE-2020-12888 'abafbc551fdd vfio-pci: Invalidate mmaps and block MMIO access on disabled memory' introduced an issue which prevented PCI Virtual Functions from being passed- through via vfio-pci as VFs are not allowed to have the PCI_COMMAND_MEMORY bit enabled per spec. This issue was initially thought to be fixed via 'ebfa440ce38b vfio/pci: Fix SR-IOV VF handling with MMIO blocking' which removes the PCI_COMMAND_MEMORY requirement for VFs but this did not solve the issue for virtual functions on s390 that are first passed through to an LPAR without their associated physical function as they are not identified as VFs in the traditional sense (there is no PF available to the host kernel to link to). As a result, when passing these devices through to a guest via vfio-pci, these devices do not trigger the check added by ebfa440ce38b which results in MMIO access from the guest being blocked because the PCI_COMMAND_MEMORY bit is off. Solution: Identify devices beyond traditional linked VFs that vfio must consider memory-enabled. Reproduction: Pass a PCI Virtual Function to a qemu-kvm guest via vfio-pci Upstream-ID: 12856e7acde4702b7c3238c15fcba86ff6aa507f 08b6e22b850c28b6032da1e4d767a33116e23dfb 515ecd5368f1510152fa4f9b9ce55b66ac56c334 These patches need to be applied for 20.10 and 20.04. The git-commits will apply cleanly on the dedicated kernels. Manx thx To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1907265/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
