Hi Paolo, Thanks a lot! On Fri, Jun 19, 2015 at 2:27 AM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > > > On 19/06/2015 03:52, Hu Yaohui wrote: >> Hi All, >> In kernel 3.14.2, the kvm uses shadow EPT(EPT02) to implement the >> nested EPT. The shadow EPT(EPT02) is a shadow of guest EPT (EPT12). If >> the L1 guest writes to the guest EPT(EPT12). How can the shadow >> EPT(EPT02) be modified according? > > Because the EPT02 is write protected, writes to the EPT12 will trap to > the hypervisor. The hypervisor will execute the write instruction > before reentering the guest and invalidate the modified parts of the > EPT02. When the invalidated part of the EPT02 is accessed, the > hypervisor will rebuild it according to the EPT12 and the KVM memslots. > Do you mean EPT12 is write protected instead of EPT02? According to my understanding, EPT12 will be write protected by marking the page table entry of EPT01 as readonly or marking the host page table entry as readonly. Could you please be more specific the code path which makes the corresponding page table entry as write protected? Thanks, Yaohui > Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in
