On 16/10/19 06:49, Derek Yerger wrote: > In at least Linux 5.2.7 via Fedora, up to 5.2.18, guest OS applications > repeatedly crash with segfaults. The problem does not occur on 5.1.16. > > System is running Fedora 29 with kernel 5.2.18. Guest OS is Windows 10 > with an AMD Radeon 540 GPU passthrough. When on 5.2.7 or 5.2.18, > specific windows applications frequently and repeatedly crash, throwing > exceptions in random libraries. Going back to 5.1.16, the issue does not > occur. > > The host system is unaffected by the regression. > > Keywords: kvm mmu pci passthrough vfio vfio-pci amdgpu > > Possibly related: Unmerged [PATCH] KVM: x86/MMU: Zap all when removing > memslot if VM has assigned device > > Workaround: Use 5.1.16 kernel. This should have been fixed in 5.2.16 through the following patches: - "[x86] Revert "KVM: x86/mmu: Zap only the relevant pages when removing a memslot" (5.2.11) - "KVM: x86/mmu: Reintroduce fast invalidate/zap for flushing memslot" (5.2.16). Paolo
