> On Feb 29, 2020, at 9:50 AM, Andy Lutomirski <luto@xxxxxxxxxx> wrote: > > KVM overloads #PF to indicate two types of not-actually-page-fault > events. Right now, the KVM guest code intercepts them by modifying > the IDT and hooking the #PF vector. This makes the already fragile > fault code even harder to understand, and it also pollutes call > traces with async_page_fault and do_async_page_fault for normal page > faults. > > Clean it up by moving the logic into do_page_fault() using a static > branch. This gets rid of the platform trap_init override mechanism > completely. > > Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx> Indeed the async-PF mechanism is only used by KVM, and there is no need for over-engineering the solution just in case some other hypervisor ever introduces support for a similar paravirtual feature. Yet, this might be a slippery slope, making Linux optimized to run on KVM (and maybe Xen). In other words, I wonder whether a similar change was acceptable for a paravirtual feature that is only supported by a proprietary hypervisor, such as Hyper-V or VMware.
