| Message ID | 20181013145406.4911-1-Tianyu.Lan@microsoft.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | x86/KVM/Hyper-v: Add HV ept tlb range flush hypercall support in KVM | expand |
On 13/10/2018 16:53, lantianyu1986@gmail.com wrote: > From: Lan Tianyu <Tianyu.Lan@microsoft.com> > > For nested memory virtualization, Hyper-v doesn't set write-protect > L1 hypervisor EPT page directory and page table node to track changes > while it relies on guest to tell it changes via HvFlushGuestAddressLlist > hypercall. HvFlushGuestAddressLlist hypercall provides a way to flush > EPT page table with ranges which are specified by L1 hypervisor. > > If L1 hypervisor uses INVEPT or HvFlushGuestAddressSpace hypercall to > flush EPT tlb, Hyper-V will invalidate associated EPT shadow page table > and sync L1's EPT table when next EPT page fault is triggered. > HvFlushGuestAddressLlist hypercall helps to avoid such redundant EPT > page fault and synchronization of shadow page table. So I just told you that the first part is well understood but I must retract that; after carefully reviewing the whole series, I think one of us is actually very confused. I am not afraid to say it can be me, but my understanding is that you're passing L1 GPAs to the hypercall and instead the spec says it expects L2 GPAs. (Consider that, because KVM's shadow paging code is shared between nested EPT and !EPT cases, every time you see gpa/gfn in the code it is for L1, while nested EPT GPAs are really what the code calls gva.) What's going on? Paolo
From: Lan Tianyu <Tianyu.Lan@microsoft.com> For nested memory virtualization, Hyper-v doesn't set write-protect L1 hypervisor EPT page directory and page table node to track changes while it relies on guest to tell it changes via HvFlushGuestAddressLlist hypercall. HvFlushGuestAddressLlist hypercall provides a way to flush EPT page table with ranges which are specified by L1 hypervisor. If L1 hypervisor uses INVEPT or HvFlushGuestAddressSpace hypercall to flush EPT tlb, Hyper-V will invalidate associated EPT shadow page table and sync L1's EPT table when next EPT page fault is triggered. HvFlushGuestAddressLlist hypercall helps to avoid such redundant EPT page fault and synchronization of shadow page table. Change since v3: 1) Remove code of updating "tlbs_dirty" in kvm_flush_remote_tlbs_with_range() 2) Remove directly tlb flush in the kvm_handle_hva_range() 3) Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte() 4) Combine Vitaly's "don't pass EPT configuration info to vmx_hv_remote_flush_tlb()" fix Change since v2: 1) Fix comment in the kvm_flush_remote_tlbs_with_range() 2) Move HV_MAX_FLUSH_PAGES and HV_MAX_FLUSH_REP_COUNT to hyperv-tlfs.h. 3) Calculate HV_MAX_FLUSH_REP_COUNT in the macro definition 4) Use HV_MAX_FLUSH_REP_COUNT to define length of gpa_list in struct hv_guest_mapping_flush_list. Change since v1: 1) Convert "end_gfn" of struct kvm_tlb_range to "pages" in order to avoid confusion as to whether "end_gfn" is inclusive or exlusive. 2) Add hyperv tlb range struct and replace kvm tlb range struct with new struct in order to avoid using kvm struct in the hyperv code directly. Lan Tianyu (15): KVM: Add tlb_remote_flush_with_range callback in kvm_x86_ops KVM/MMU: Add tlb flush with range helper function KVM: Replace old tlb flush function with new one to flush a specified range. KVM: Make kvm_set_spte_hva() return int KVM/MMU: Move tlb flush in kvm_set_pte_rmapp() to kvm_mmu_notifier_change_pte() KVM/MMU: Flush tlb directly in the kvm_set_pte_rmapp() KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range() KVM/MMU: Flush tlb directly in kvm_mmu_zap_collapsible_spte() KVM: Add flush_link and parent_pte in the struct kvm_mmu_page KVM: Add spte's point in the struct kvm_mmu_page KVM/MMU: Replace tlb flush function with range list flush function x86/hyper-v: Add HvFlushGuestAddressList hypercall support x86/Hyper-v: Add trace in the hyperv_nested_flush_guest_mapping_range() KVM/VMX: Change hv flush logic when ept tables are mismatched. KVM/VMX: Add hv tlb range flush support arch/arm/include/asm/kvm_host.h | 2 +- arch/arm64/include/asm/kvm_host.h | 2 +- arch/mips/include/asm/kvm_host.h | 2 +- arch/mips/kvm/mmu.c | 3 +- arch/powerpc/include/asm/kvm_host.h | 2 +- arch/powerpc/kvm/book3s.c | 3 +- arch/powerpc/kvm/e500_mmu_host.c | 3 +- arch/x86/hyperv/nested.c | 85 ++++++++++++++++++++++ arch/x86/include/asm/hyperv-tlfs.h | 32 +++++++++ arch/x86/include/asm/kvm_host.h | 12 +++- arch/x86/include/asm/mshyperv.h | 16 +++++ arch/x86/include/asm/trace/hyperv.h | 14 ++++ arch/x86/kvm/mmu.c | 138 ++++++++++++++++++++++++++++++------ arch/x86/kvm/paging_tmpl.h | 10 ++- arch/x86/kvm/vmx.c | 70 +++++++++++++++--- virt/kvm/arm/mmu.c | 6 +- virt/kvm/kvm_main.c | 5 +- 17 files changed, 360 insertions(+), 45 deletions(-)