kernel mode : mmu

[Martins3]

Something related to emualted:

• [x] mapped and unmapped
  • [x] kvm_mips_gpa_pte_to_gva_unmapped, kvm_mips_gpa_pte_to_gva_mapped
  • [x] kvm_mips_handle_kseg0_tlb_fault <= kvm_trap_emul_gva_fault <= kvm_get_inst <= used by emulate.c
• [x] kseg0
  • kvm_mips_handle_kseg0_tlb_fault
• [x] emulated
  • x: kvm_trap_emul_gva_fault
    • x: kvm_get_inst
  • kvm_mips_handle_mapped_seg_tlb_fault : caller is emulate

    Boring stuff

  • [x] move mmu notifier to mmu.c
  • [ ] kvm_pgd_alloc
  • [ ] examine transparent hugepage
  • [ ] dune_arch_vcpu_put : some effort to complete the code
  • [ ] kvm_mips_handle_commpage_tlb_fault : now that commpage is used for tlb, should dune remove it ?
  • [ ] remove kvm_host.c
  • [ ] remove dirty bit tracking in mmu.c

    vcpu, ept and guest page table

  • A sthread fork will create two guest page table
  • A Linux fork with VM clone will create two
  • A dune_enter doesn't create user space percpu
• dune_enter create a new vcpu and ept

  kvm_memory_slot

  • [x] maybe we should take advantage of it
  • [x] move memory_slot related code into one place

[Martins3]

• [ ] can vz_vm substitude kvm in mmu.c ?
• [ ] it's kvm_flush_remote_tlbs necessary ?
  • [x] vz_vm::tlbs_dirty : why we need it ? (No, only x86 use it, in the paging_tmpl.h)
  • [x] There is no doubt local TLB flush is obligatory
  • [x] flush remote is necessary if ept is shared by multiple vcpu
  • [ ] Should dune support remote tlb flush
  • [ ] What's the difference between two separate ept and one sharing ept?
    • ept mapping is the same
    • [x] does dune create two ept with fork ? (yes, but shouldn't) vmx_launch -> vmx_create_vcpu -> vmx_init_ept will create new cpu.
    • [x] should dune create a new vcpu for every process?
      • it's possible, but need some efforts like sthread, and set a limitation on two processes where they can't run simultaneously