On Fri, Dec 9, 2016 at 11:15 AM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > > > On 09/12/2016 17:16, Jim Mattson wrote: >> At the very least, it needs to know the following to do a page walk: >> >> a) Are the secondary processor based VM-execution controls activated >> in the pimary processor based execution controls? >> b) If so, is EPT enabled? >> c) If so, what is the current EPTP? > > Oh, I see; this is when MMIO is passed through from L1 to L2. Though > there is also the KVM_TRANSLATE ioctl. I like the idea of supporting just one guest page walker, but KVM_TRANSLATE looks incomplete. For instance, it doesn't include the access type, which makes me wonder how it deals with SMEP faults. Also, it doesn't seem to have a way to return page fault information to the caller, let alone EPT violation information if the VCPU is in VMX non-root mode. (Is there currently a way for userspace to cause an emulated EPT violation VM-exit from L2 to L1 as the result of instruction emulation?) > > Paolo
