| _2025-06-20_11：16：32_ | 2025-06-20 11：16：32 | | 【KVM虚拟化技术深度解析】：掌握QEMU-KVM的CPU管理秘籍 - CSDN文库 | | 原文链接失效了?试试备份 | | TAGs:虚拟化&容器 cpu | | Summary: This text provides a comprehensive overview and in-depth analysis of KVM virtualization technology. It begins by introducing the basics of KVM virtualization and its collaboration with QEMU. Then, it explores CPU virtualization technology, including hardware assisted virtualization, challenges and solutions, CPU scheduling policies, and performance optimization cases. Through practical chapters, the text offers techniques for virtual machine CPU configuration, hot plugging, and dynamic migration. It also discusses advanced CPU management techniques, such as multi-virtual CPU configuration optimization, CPU affinity and isolation, performance tuning, and fault diagnosis. Lastly, it looks to the future of KVM virtualization CPU management, including new hardware support, community development, and contributions. This text is valuable for virtualization technology developers and administrators, providing essential information and practical guidelines.本文对 KVM 虚拟化技术进行了全面概述和深入分析。它首先介绍了 KVM 虚拟化的基础知识及其与 QEMU 的协作。然后，它探讨了 CPU 虚拟化技术，包括硬件辅助虚拟化、挑战和解决方案、CPU 调度策略和性能优化案例。通过实践章节，该教材提供了虚拟机 CPU 配置、热插拔和动态迁移的技术。它还讨论了高级 CPU 管理技术，例如多虚拟 CPU 配置优化、CPU 关联和隔离、性能调整和故障诊断。最后，它展望了 KVM 虚拟化 CPU 管理的未来，包括新硬件支持、社区开发和贡献。本文对虚拟化技术开发人员和管理员很有价值，它提供了基本信息和实用指南。 | |
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| _2025-03-31_14：35：51_ | 2025-03-31 14：35：51 | | 虚拟机中的 HLT 优化_ kvm-poll-control - 知乎 | | 原文链接失效了?试试备份 | | TAGs:虚拟化&容器 kvm cpu idle | | Summary: This text is about the implementation and functionality of KVM's halt poll control feature, which is a paravirtualization (PV) technique used in the Linux kernel to optimize virtualization by transferring the polling (round-robin checking) phase of HLT (halt processor) instructions from the host to the guest. This can help reduce some HLT-induced VM-exits. The text also discusses the background and working mechanism of this feature by referring to the Linux kernel code. | |
| _2025-03-31_21：55：14_ | 2025-03-31 21：55：14 | | 虚拟机中的 HLT 优化_ kvm-poll-control - 知乎 | | 原文链接失效了?试试备份 | | TAGs:虚拟化&容器 kvm cpu idle | | Summary: The Linux kernel function `wait_for_random_bytes` is used to ensure that the random number generator (RNG) in the Linux kernel is ready and has sufficient entropy before continuing execution in situations where secure random numbers are required, such as encryption operations or key generation. The function blocks the current thread until the RNG has completed initialization and has an adequate amount of entropy. It is particularly important during system startup or when the entropy pool has not yet accumulated sufficient random data. By using `wait_for_random_bytes`, developers can prevent the generation of weak random numbers, which could lead to security vulnerabilities. The function works by checking if the RNG is ready using the `crng_ready()` function. If the RNG is not yet initialized, the function blocks the current thread and adds it to the `crng_init_wait` queue, waiting until the RNG is ready to continue execution. The function can be used in various contexts, such as in driver initialization or in generating secure tokens. It is essential to note that the function should only be used in contexts where sleeping is allowed, as it may call functions that cause the system to sleep, such as `wait_event`. Additionally, the function can have performance implications, especially during system startup when the entropy pool may take a long time to initialize. Alternative solutions include using non-blocking functions or actively adding entropy sources to the pool. Related functions include `get_random_bytes`, `add_hwgenerator_randomness`, and `urandom_read`.Linux 内核函数 'wait_for_random_bytes' 用于确保 Linux 内核中的随机数生成器 （RNG） 已准备就绪并具有足够的熵，然后才能在需要安全随机数的情况下继续执行，例如加密作或密钥生成。该函数会阻止当前线程，直到 RNG 完成初始化并具有足够的熵量。在系统启动期间或熵池尚未积累足够的随机数据时，这一点尤为重要。通过使用 'wait_for_random_bytes'，开发人员可以防止产生弱随机数，这可能会导致安全漏洞。该函数通过使用 'crng_ready（）' 函数检查 RNG 是否准备就绪来工作。如果 RNG 尚未初始化，该函数会阻止当前线程并将其添加到 'crng_init_wait' 队列中，等待 RNG 准备好继续执行。该函数可用于各种上下文，例如驱动程序初始化或生成安全令牌。需要注意的是，该函数只应在允许休眠的上下文中使用，因为它可能会调用导致系统休眠的函数，例如 'wait_event'。此外，该函数可能会对性能产生影响，尤其是在系统启动期间，此时熵池可能需要很长时间才能初始化。替代解决方案包括使用非阻塞函数或主动向池中添加熵源。相关函数包括 'get_random_bytes'、'add_hwgenerator_randomness' 和 'urandom_read'。 | |