Dropping Non-KVM folks/lists. On Fri, Jan 17, 2025, C CHI wrote: > I roughly understand the above content. Heh, you top posted, so it's below. https://people.kernel.org/tglx/notes-about-netiquette > The main reason for this phenomenon seems to be the chaotic VM memory layout > caused by the syzkaller template settings. In fact, it’s even observable that > the IDT region in the code doesn’t actually contain any exception handling > code, very amusing :) > > Additionally, I would like to ask about the previously mentioned point > where the IDT is set in the emulated MMIO space. How can I verify > this, and where can I find the relevant code for setting the MMIO > region? In KVM, any guest address that isn't covered by a memslot, a.k.a. a user memory region, is treated as emulated MMIO. > The guest loops because the the guest's IDT is located in emulated > MMIO space, > and as suspected above, KVM refuses to emulates HLT for L2. > > > Also, I'm curious as to what technique is used to get the following > type of logging information, and I'd like to be able to get each ENTRY > and EXIT info on the run The below comes from KVM's tracepoints. E.g. if tracefs is mounted at /sys/kernel/debug/trace, all KVM tracepoints can be enabled via: /sys/kernel/debug/tracing/events/kvm/enable See Documentation/trace/tracepoints.rst for details on using tracepoints (or the same info in the web version https://docs.kernel.org/trace/tracepoints.html).
