On Wed, 16 Oct 2019 00:49:51 -0400 Derek Yerger <derek@xxxxxxx> 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 if VM has assigned device That was never merged because it was superseded by: d012a06ab1d2 Revert "KVM: x86/mmu: Zap only the relevant pages when removing a memslot" That revert also induced this commit: 002c5f73c508 KVM: x86/mmu: Reintroduce fast invalidate/zap for flushing memslot Both of these were merged to stable, showing up in 5.2.11 and 5.2.16 respectively, so seeing these sorts of issues might be considered a known issue on 5.2.7, but not 5.2.18 afaik. Do you have a specific test that reliably reproduces the issue? Thanks, Alex
