Public bug reported: [Impact] Performance is degraded when a guest is booted w/ vgic v4 support enabled.
[Test Case] I used a HiSilicon D06 system w/ an Intel 82599 10Gbps NIC. I passed through a VF to a guest, and ran "netperf -H <host>" against a 10Gbps-capable target. With vgic v4 support, I'm only seeing 5-6Gbps. With vgic v3 support, this was in the 9Gbps spectrum. And, after applying the upstream fix, I'm also seeing >9Gbps w/ vgic v4 enabled. Note: to enable vgic v4 support, pass "kvm-arm.vgic_v4_enable=1" on the host kernel cmdline. [Fix] ca71228b42a96 arm64: KVM: Always set ICH_HCR_EL2.EN if GICv4 is enabled [Regression Risk] The fix is restricted to the ARM/KVM subsystem. ** Affects: linux (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1829942 Title: Address performance issue w/ GICv4-based guests To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1829942/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs