html5-img
1 / 5

x86 MMU

x86 MMU. Shadow Page Table. Extended Page Table . Guest wants to access GVA 0 , guest PTE (page table entry) maps GVA 0 to GPA 0 Hardware checks NPT (nested page table) NPT entry for GPA 0 is empty, we have a NPT page fault

chad
Télécharger la présentation

x86 MMU

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. x86 MMU

  2. Shadow Page Table

  3. Extended Page Table

  4. Guest wants to access GVA 0, guest PTE (page table entry) maps GVA 0 to GPA 0 • Hardware checks NPT (nested page table) • NPT entry for GPA 0 is empty, we have a NPT page fault • KVM goes in, checks where GPA 0 is mapped (through memslots), finds GPA 0 -> HVA x,resolves HVA x to HPA y (through QEMU page table), adds GPA 0 -> HPA y mapping to the NPT • Guest runs again, the memory access it did before would resolve GVA 0 -> GPA 0 -> HPA y

  5. GVA -> GPA (guest page table) • GPA -> HVA (memslot) • HVA -> HPA (QEMU page table) • GPA -> HPA (nested page table)

More Related