Evaluate using Profile-Guided Optimization (PGO)

[zamazan4ik]

Hi!

Recently I checked Profile-Guided Optimization (PGO) improvements on multiple projects including many projects - the results are available in the awesome-pgo repo. Since PGO has helped in many cases, I think it would be a good idea to try optimizing SVSM by applying PGO to it.

I can suggest the following things to do:

• We need to perform PGO benchmarks on SVSM. If it shows improvements - add a note about possible improvements to the documentation. Providing an easier way (e.g. a build option) to build scripts to build SVSM with PGO can be useful for the end-users too.
• It will be a good idea to integrate building with PGO into your CI pipelines. In this case, users will get already PGO-optimized binaries from the website (if you are going to provide prebuilt binaries, of course)

For the Rust projects, I suggest trying to start with cargo-pgo.

Here you can find different materials about PGO: benchmarks in different software (including kernels like Linux kernel and VMs like CrosVM), examples of how PGO is already integrated with different projects, PGO support in multiple Rust compilers, and some PGO-related pieces of advice.

After PGO, I suggest evaluating the LLVM BOLT optimizer - it can give more aggressive optimizations even after PGO. However, starting with regular PGO will be easier to do.