https://lihuiba.github.io/en/Recent content on Deep in the clouds, I know not where.Hugoen-USMon, 24 Aug 2026 00:00:00 +0000https://lihuiba.github.io/en/p/microkernel-vmm-done-right/Mon, 24 Aug 2026 00:00:00 +0000https://lihuiba.github.io/en/p/microkernel-vmm-done-right/In 2005 the Xen team asked whether VMMs are microkernels done right; over twenty years isolation went to microVMs, the dataplane to silicon, discipline to DPUs, and only 'the service stack restarts painlessly' went unclaimed — this article traces that history and its four obstacles, then offers a pure-software assembly: a thin core defined as firmware, stateless service VMs, a dataplane delegated to silicon, holding with VM boundaries and the IOMMU the boundary the DPU holds with PCIe.https://lihuiba.github.io/en/p/end-of-dpu-myth/Thu, 20 Aug 2026 00:00:00 +0000https://lihuiba.github.io/en/p/end-of-dpu-myth/Every large-scale DPU success comes from a hyperscaler's vertically integrated, in-house program, while the merchant DPU market is a complete wreck. An attribution audit of its seven value propositions: five do not survive scrutiny, one is real but software-replaceable, and one is real but worth only half — half a claim left standing out of seven. Thin value wrapped in a thick narrative is the standard recipe for a myth.https://lihuiba.github.io/en/p/against-fixed-output/Mon, 17 Aug 2026 00:00:00 +0000https://lihuiba.github.io/en/p/against-fixed-output/Fixed-output compression — variable-length input stuffed into fixed-size output blocks — was credited with eliminating read amplification, aligning I/O, improving compression ratio, and saving memory. Term-by-term attribution finds otherwise: these benefits belong to granularity choices, to the index and the decompressor, hold only inside a restricted framing, or cannot be found in measurement at all — while the costs are format-level and permanent. The conclusion is polite but total: as a format design decision, fixed-output is not worth adopting.https://lihuiba.github.io/en/p/overlaybd-the-ultimate-image-format/Mon, 10 Aug 2026 00:00:00 +0000https://lihuiba.github.io/en/p/overlaybd-the-ultimate-image-format/OCI tar layers for containers, qcow2 for VMs — both carry structural costs. Overlaybd is a layered, lazily-loaded, seekably-compressed block-device image format for every workload: sub-second cold starts, proven in production across many companies.https://lihuiba.github.io/en/p/hello-world/Sun, 09 Aug 2026 00:00:00 +0000https://lihuiba.github.io/en/p/hello-world/The first post of this bloghttps://lihuiba.github.io/en/p/stackful-coroutine-made-fast/Mon, 14 Oct 2024 00:00:00 +0000https://lihuiba.github.io/en/p/stackful-coroutine-made-fast/Stackful coroutine is not intrinsically slow — current implementations are. With context-aware context switching (CACS), saving only the minimal registers per caller/callee context, stackful outperforms stackless in most cases and ties otherwise. Implemented in Photon.https://lihuiba.github.io/en/p/ipmi-shared-lan-setup/Wed, 26 Mar 2014 22:51:49 +0800https://lihuiba.github.io/en/p/ipmi-shared-lan-setup/Multiplexing the eth0 port with VLANs to run IPMI over the shared network interface