[RFC Patch 0/3] KVM/x86/hyper-V: Introduce PV guest address space mapping flush support

[Tianyu Lan <Tianyu.Lan@microsoft.com>]

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.

Lan Tianyu (3):
  X86/Hyper-V: Add flush HvFlushGuestPhysicalAddressSpace hypercall
    support
  KVM: Add tlb remote flush callback in kvm_x86_ops.
  KVM/x86: Add tlb_remote_flush callback support for vmcs

 arch/x86/hyperv/Makefile           |  2 +-
 arch/x86/hyperv/nested.c           | 64 ++++++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/hyperv-tlfs.h |  8 +++++
 arch/x86/include/asm/kvm_host.h    |  1 +
 arch/x86/include/asm/mshyperv.h    |  2 ++
 arch/x86/kvm/vmx.c                 | 15 +++++++++
 virt/kvm/kvm_main.c                | 12 ++++++-
 7 files changed, 102 insertions(+), 2 deletions(-)
 create mode 100644 arch/x86/hyperv/nested.c

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2.14.3