Still broken with Qemu 4.1rc2 /w Kernel 5.2. This is a huge problem, as it breaks performance, either in networking (you can't use the virtio net which is the only 100G adapter afaik), or you have to disable huge pages, which is a blow to any large vm host, or it breaks stimer, which increases cpu usage, generally breaking virtualization.
Thank you! -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1811533 Title: Unstable Win10 guest with qemu 3.1 + huge pages + hv_stimer Status in QEMU: New Bug description: Host: Gentoo linux x86_64, kernel 4.20.1 Qemu 3.1.0 CPU: Intel i7 6850K Chipset: X99 Guest: Windows 10 Pro 64bit (1809) Machine type: pc-q35_3.1 Hyper-V enlightenments: hv_stimer,hv_reenlightenment,hv_frequencies,hv_vapic,hv_reset,hv_synic,hv_runtime,hv_vpindex,hv_time,hv_relaxed,hv_spinlocks=0x1fff Memory: 16GB backed by 2MB huge pages Issue: Once guest is started, log gets flooded with: qemu-system-x86_64: vhost_region_add_section: Overlapping but not coherent sections at 103000 or qemu-system-x86_64: vhost_region_add_section:Section rounded to 0 prior to previous 1f000 (line endings change) and as time goes guest loses network access (virtio-net-pci) and general performance diminishes to extent of freezing applications. Observations: 1) problem disappears when hv_stimer is removed 2) problem disappears when memory backing with huge pages is disabled 3) problem disappears when machine type is downgraded to pc-q35_3.0 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1811533/+subscriptions
