Seamless vGPU Migration: Enhancing Performance and Compatibility

Table of Contents:

1. Introduction 🌟
2. GPU Innovations and VGP Life Mars
3. Challenges in VGP Instance Migration
4. Solutions for GPU Visualizations
   • GVG Pass-Through Solutions
   • SV Solutions
   • ZT GVG Solutions
5. GTG Project Highlights
6. Migration of GPU Page Tables
7. Migration of Graphic Memories
8. Migration of Running Engines
9. Summary and Performance
10. Resources

Introduction 🌟

In this article, we will explore the topic of live migration for GPU visualizations. We will dive into the technical aspects, challenges, and solutions involved in migrating Virtual GPU (VGP) instances. GPU visualizations are essential for various workloads, such as 3D or 2D workload on a graphics site, remote VDI usage models, and real-time processings. To enable the seamless migration of VGP instances, the ZT GPU Solutions project offers a mediated pass-through solution called GVG. This open-source project provides efficient live migration capabilities while ensuring compatibility and performance. Let's delve into the details.

GPU Innovations and VGP Life Mars

GPU visualizations play a vital role in accelerating 3D or 2D workloads, remote VDI usage models, and real-time processing tasks. The demand for GPU validations in cloud and data center sites has led to the development of innovative solutions like VGP Life Mars. These solutions offer GPU valuation capabilities for Intel graphic processors. By leveraging technologies such as ZT (Zero Time) and GPU pass-through, VGP Life Mars provides performance enhancements and resource optimization for GPU workloads. This brings remarkable benefits to various domains, including remote CDAs and 2D/3D productivity applications.

Challenges in VGP Instance Migration

Despite the advantages of GPU visualizations, migrating VGP instances poses several challenges. The first challenge lies in understanding the structure and resources within a VGP instance. This includes the intricate graphics page tables (gtt page tables), MMO registers, and pass-through regions. Additionally, ensuring a smooth migration requires overcoming the limitations of existing VGP solutions, such as GPU pass-through and SV solutions. These limitations involve difficulties in tracking dirty or accessed pages, which hampers efficient pre-copy migration. Addressing these challenges is crucial to facilitate seamless and secure VGP instance migration.

Solutions for GPU Visualizations

1. GVG Pass-Through Solutions: This approach involves assigning a dedicated GPU context (GPOC) to a specific VM through hardware-level models. However, GPU pass-through poses limitations in tracking details about GPU status, making migrations more complex.

2. SV Solutions: SV (Shared Virtualization) solutions utilize GPU Physical Function (PF) and Virtual Functions (VFs) models. This approach allows multiple VMs to share a single VF, but it faces similar challenges as GPU pass-through in terms of tracking GPU status during migration.

3. ZT GVG Solutions: To address the limitations of previous solutions, the ZT GVG architecture provides mediated pass-through capabilities for VGP instances. It traps and emulates most resources, including MMO registers and graphic page tables, to ensure proper migration. By focusing on high-performance critical results like graphic memory access, ZT GVG Solutions guarantee efficient and secure GPU migrations.

GTG Project Highlights

The GTG (GPU Time-Gap) project offers an open-source solution for live migration of VGP instances. With GTG, users can seamlessly migrate GPU workloads between different servers without data loss. The project emphasizes simplicity, compatibility, and performance. Key highlights of GTG include:

• Open-source project with regular code releases.
• Compatible with Linux and Windows guests (Windows 7, 8, and 10).
• Support for 3D, 2D, and media workloads.
• Efficient live migration with a service downtime of around 300 milliseconds on a 10G network adapter.
• Demonstrated successful migration of diverse workloads using benchmark tests.

Migration of GPU Page Tables

The migration of GPU page tables (gtt page tables) is a critical aspect of VGP instance migration. The gtt page tables, similar to CPU page tables, control GPU memory access and address translation. During the migration process, the entire table is copied to the target site, and shadow links are created for efficient migration. Additionally, the GPU address rebasing technique ensures proper reassignment of addresses to maintain coherence during migration. This ensures a seamless transition of GPU-focused workloads without disruptions or data loss.

Migration of Graphic Memories

Efficient migration of graphic memories is crucial for maintaining performance during VGP instance migration. By leveraging pre-copy and stop-and-copy stages, GTG ensures that dirty graphic pages are properly logged and copied to the target site. The migration policy involves checking dirty pages, copying and updating the graphic memory content, and transferring the contents to the target hardware. This approach guarantees data integrity and minimal downtime, preserving the visual experience without compromising performance.

Migration of Running Engines

Running engines within VGP instances pose unique challenges during migration. Focusing on efficient workload distribution, GTG divides the running engines into time-sliced partitions. Each partitioned engine is assigned to a specific VM, allowing for seamless transitions between workloads. By saving and migrating the state of the running engines, GTG ensures continuity and uninterrupted performance during the migration process.

Summary and Performance

In summary, GPU visualizations and the migration of VGP instances are critical for optimal performance and resource utilization in various domains. The ZT GVG project offers a mediated pass-through solution to address challenges and provide efficient migration capabilities. Highlights of GTG include open-source accessibility, compatibility with major operating systems, support for diverse workloads, and excellent migration performance. With GTG, users can seamlessly migrate VGP instances, ensuring continuous operation and enhanced productivity.

Resources

• GTG Project Website: https://gtg.org
• Documentation: https://gtg.org/docs
• IDF Presentations: https://gtg.org/idf-presentations
• Additional Summit on GPU Virtualization: https://gtg.org/summit-presentations

Note: The GTG project website and its associated resources provide detailed information and documentation for further exploration of GPU virtualization and VGP instance migration.

📌 Pros:

• Open-source project with regular code releases
• Compatibility with both Linux and Windows guests
• Efficient live migration capabilities
• Seamless transitions without data loss

📌 Cons:

• Challenges in tracking dirty or accessed pages during migration
• Lack of support for dynamic GPU address rebasing
• Limited optimization for memory pre-copying

In conclusion, the GTG project offers a valuable solution for GPU virtualization and VGP instance migration. With ongoing development and improvements, it has the potential to enhance GPU-based workloads and simplify the migration process for a more seamless user experience.