Enabling GICv4.1
GICv4.1 incorporates interrupt direct injection capabilities like vLPI passthrough for devices and vSGI passthrough. These features dramatically decrease VM-exit and VM-entry occurrences in heavily loaded VMs, resulting in enhanced VM performance.
- Modify BIOS settings.
In , change GIC Version to 4.1, as shown in the following figure.
- Modify the kernel cmdline startup parameters.
Add kvm-arm.vgic_v4_enable=1 to cmdline. Restart the server.
- Ensure that GICv4.1 is enabled.
Run the dmesg | grep GIC command on the host. If "kvm [1]: GICv4.1 support enabled" is displayed, GICv4.1 is enabled.
When the network bandwidth is tested on a VM with 4 vCPUs and 8 GB memory, network interrupts and application workloads run simultaneously across all four vCPUs due to the limited number of cores. For controlled testing of network bandwidth across four CPU cores on a physical machine, both network interrupts and service operations must be confined to those same four cores.