[PATCH V3 0/4] KVM/x86/hyper-V: Introduce PV guest address space mapping flush support

From: Tianyu Lan
Date: Thu Jul 19 2018 - 04:40:12 EST


Hyper-V provides a para-virtualization hypercall HvFlushGuestPhysicalAddressSpace
to flush nested VM address space mapping in l1 hypervisor and it's to reduce overhead
of flushing ept tlb among vcpus. The tradition way is to send IPIs to all affected
vcpus and executes INVEPT on each vcpus. It will trigger several vmexits for IPI and
INVEPT emulation. The pv hypercall can help to flush specified ept table on all vcpus
via one single hypercall.

Change since v2:
- Make ept_pointers_match as tristate "check", "match" and "mismatch".
Set "check" in vmx_set_cr3(), check all ept table pointers in hv_remote_flush_tlb()
and call hypercall when all ept pointers are same.
- Rename kvm_arch_hv_flush_remote_tlb with kvm_arch_flush_remote_tlb and
Rename kvm_x86_ops->hv_tlb_remote_flush with kvm_x86_ops->tlb_remote_flush
- Fix issue that ignore updating tlbs_dirty during calling kvm_arch_flush_remote_tlbs()
- Merge patch "KVM/VMX: Add identical ept table pointer check" and
patch "KVM/x86: Add tlb_remote_flush callback support for vmx"

Change since v1:
- Fix compilation error for non-x86 platform.
- Use ept_pointers_match to check condition of identical ept
table pointer and get ept pointer from struct vcpu_vmx->ept_pointer.
- Add hyperv_nested_flush_guest_mapping ftrace support



Lan Tianyu (4):
X86/Hyper-V: Add flush HvFlushGuestPhysicalAddressSpace hypercall
support
X86/Hyper-V: Add hyperv_nested_flush_guest_mapping ftrace support
KVM: Add tlb remote flush callback in kvm_x86_ops.
KVM/x86: Add tlb_remote_flush callback support for vmx

arch/x86/hyperv/Makefile | 2 +-
arch/x86/hyperv/nested.c | 67 ++++++++++++++++++++++++++++++++++
arch/x86/include/asm/hyperv-tlfs.h | 8 +++++
arch/x86/include/asm/kvm_host.h | 11 ++++++
arch/x86/include/asm/mshyperv.h | 2 ++
arch/x86/include/asm/trace/hyperv.h | 14 ++++++++
arch/x86/kvm/vmx.c | 72 ++++++++++++++++++++++++++++++++++++-
include/linux/kvm_host.h | 7 ++++
virt/kvm/kvm_main.c | 3 +-
9 files changed, 183 insertions(+), 3 deletions(-)
create mode 100644 arch/x86/hyperv/nested.c

--
2.14.3