QEMU hot-replace

• QEMU hot-replace is a technology which can promptly upgrade QEMU without interrupting customer VMs.
• I was responsible for developing the framework via fork+exec, serialization/ deserialization of device status and management of VM life cycle via PIPE.

Support enable/disable CPU features for AArch64

• The feature adds support to enable/disable CPU features for guests so that the cloud provides can expose a uniform set of features for a group of guests on systems with different ARM CPUs.
• I was responsible for developing code to allow userspace to modify a value of ID registers in KVM. I was also responsible for configuring ID registers and writing them to KVM.

• patches of openEuler kernel
• patches of openEuler QEMU

A-Tune

• A-Tune is an OS tuning engine powered by AI. A-Tune uses AI technologies to enable the OS to understand services, simplify IT system tuning, and maximize application performance.
• I was responsible for tuning performance of Hadoop, Spark, SPECJbb2015, and Dubbo so that the performance of those were improved by 30%, 30%, 40%, and 10%. I was also responsible for refactoring of the module of data collecting and parsing to improve the scalability and configurability.

Support DBM of stage-2 for AArch64

• Dirty page logging is important for pre-copy model migration. AArch64 only support software way currently by marking all pages write-protected, which is inefficient because writing to memory in guest will trap to KVM.
• I was responsible for developing hardware dirty page logging via DBM bit of stage-2 pgtable. Comparing to software dirty page logging, the number of traps decreases 30%~80% during migration when using hardware dirty page logging.

Contributions to community

• Contributions to QEMU
• Contributions to libvirt