Firecracker knows how to boot PVH. The FreeBSD kernel has a Xen PVH entry point with just a few lines of Xen-specific code. Hmm... Firecracker isn't finding FreeBSD's PVH entry point. It's trying to launch the VM anyway (bug?) but it exits immediately with KVM_EXIT_SHUTDOWN.

Something @patio11 mentions often but I think is widely underappreciated is the unreasonable effectiveness of strong communication skills and their correlation with social status / privilege. 🧵⬇️ I serve as an alumni representative on my Alma Mater's undergraduate financial aid adjudication committee, and as a result I get to see a large corpus of writing by (and largely about) current and future undergraduate students. The quality varies tremendously.

To many people, @coinbase is a great @ycombinator success story. And from an immediate financial perspective, it is: They're now valued at around $100B.

To me, the coinbase story is a worrying one which diminishes my respect and trust in YC. We now know that in the early days of coinbase, employees participated in widespread fraud and the company turned a blind eye to it. This is not ethical behaviour.

So about that "Lazy FPU" vulnerability (CVE-2018-3665)... this probably ought to be a blog post, but the embargo just ended and I think it's important to get some details out quickly. This affects recent Intel CPUs. It might affect non-Intel CPUs but I have no evidence of that. It is an information leak caused by speculative execution, affecting operating systems which use "lazy FPU context switching".