[PATCH v4 0/3] Expose VMFUNC to the nested hypervisor

From: Bandan Das
Date: Mon Jul 10 2017 - 16:50:41 EST

2/3: Use WARN_ONCE to avoid logging dos

3/3: Add missing nested_release_page_clean() and check the
eptp as mentioned in SDM 24.6.14

1/3: Patch to enable vmfunc on the host but cause a #UD if
L1 tries to use it directly. (new)
2/3: Expose vmfunc to the nested hypervisor, but no vm functions
are exposed and L0 emulates a vmfunc vmexit to L1.
3/3: Force a vmfunc vmexit when L2 tries to use vmfunc and emulate
eptp switching. Unconditionally expose EPTP switching to the
L1 hypervisor since L0 fakes eptp switching via a mmu reload.

These patches expose eptp switching/vmfunc to the nested hypervisor.
vmfunc is enabled in the secondary controls for the host and is
exposed to the nested hypervisor. However, if the nested hypervisor
decides to use eptp switching, L0 emulates it.


Bandan Das (3):
KVM: vmx: Enable VMFUNCs
KVM: nVMX: Enable VMFUNC for the L1 hypervisor
KVM: nVMX: Emulate EPTP switching for the L1 hypervisor

arch/x86/include/asm/vmx.h | 9 ++++
arch/x86/kvm/vmx.c | 125 ++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 132 insertions(+), 2 deletions(-)