為了解決GPGPU虛擬化的問題，在本篇論文中我們提出qCUDA：基於QEMU
virtio對NVIDIA CUDA虛擬化解決方案。我們以QEMU 2.4.0、NVidia CUDA 7.5和Ubuntu
14.04.3為基礎，實作出qCUDA。qCUDA利用API forward的方式讓使用者可以在虛
擬中使用NVidia CUDA API。qCUDA架構由上而下主要分為三個部分，函式庫、
驅動程式和虛擬硬體裝置。在實驗方面，我們進行了三種不同類別的實驗：記
憶體頻寬實驗、計算密集型實驗和記憶體密集型實驗，並且和原生CUDA以及
目前常用的GPGPU虛擬系統rCUDA相比較。在記憶體頻寬實驗中雖然qCUDA只
有原生CUDA的50%，但rCUDA卻只有5%。而在計算密集型實驗中，小資料量
時qCUDA比rCUDA快2000%、在大資料量時qCUDA也比rCUDA快200%以上。最後
在記憶體密集型實驗中qCUDA比rCUDA快1000%~˜2500%。

Virtualization has become a key technology in cloud computing. However, no single
solution of GPGPU virtualization can satisfy all different demands. In this thesis, we propose
qCUDA: a GPGPU virtualization method based on QEMU virtio for NVidia CUDA.
The architecture of qCUDA consists of three parts: library, driver, and virtual hardware
devices. The virtualization method of qCUDA is based on API forwarding, which accepts
users’ invocation of CUDA API in the virtual machine, and forwards the APIs to the physical
machine through virtIO and QEMU. The experiments evaluate three different types of
benchmarks, which are of bandwidth bound, computational bound, and memory bound,
and compare qCUDA with native CUDA and rCUDA, which is a popular GPGPU virtualization
method. For the bandwidth bound benchmark, qCUDA can reach 50% bandwidth
performance of native CUDA, but rCUDA can only have 3% bandwidth performance of
native CUDA. For the computational bound benchmark, qCUDA is 2000% time faster than
rCUDA for a small data size and 200% time faster than rCUDA for a large data size. For
the memory-bound benchmark, qCUDA is 1000%~˜2500% times faster than rCUDA.

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