[RFC v3 0/7] KVM: PKS Virtualization support

[Chenyi Qiang]

Protection Keys for Supervisor Pages(PKS) is a feature that extends the
Protection Keys architecture to support thread-specific permission
restrictions on supervisor pages.

PKS works similar to an existing feature named PKU(protecting user pages).
They both perform an additional check after all legacy access
permissions checks are done. If violated, #PF occurs and PFEC.PK bit will
be set. PKS introduces MSR IA32_PKRS to manage supervisor protection key
rights. The MSR contains 16 pairs of ADi and WDi bits. Each pair
advertises on a group of pages with the same key which is set in the
leaf paging-structure entries(bits[62:59]). Currently, IA32_PKRS is not
supported by XSAVES architecture.

This patchset aims to add the virtualization of PKS in KVM. It
implemented PKS CPUID enumeration, vmentry/vmexit configuration, MSR
exposure, nested supported etc. Currently, PKS is not yet supported for
shadow paging. 

Detailed information about PKS can be found in the latest Intel 64 and
IA-32 Architectures Software Developer's Manual.

---

Changelogs:

v2->v3:
- No function changes since last submit
- rebase on the latest PKS kernel support:
  https://lore.kernel.org/lkml/20201102205320.1458656-1-ira.weiny@xxxxxxxxx/
- add MSR_IA32_PKRS to the vmx_possible_passthrough_msrs[]
- RFC v2: https://lore.kernel.org/lkml/20201014021157.18022-1-chenyi.qiang@xxxxxxxxx/

v1->v2:
- rebase on the latest PKS kernel support:
  https://github.com/weiny2/linux-kernel/tree/pks-rfc-v3
- add a kvm-unit-tests for PKS
- add the check in kvm_init_msr_list for PKRS
- place the X86_CR4_PKS in mmu_role_bits in kvm_set_cr4
- add the support to expose VM_{ENTRY, EXIT}_LOAD_IA32_PKRS in nested
  VMX MSR
- RFC v1: https://lore.kernel.org/lkml/20200807084841.7112-1-chenyi.qiang@xxxxxxxxx/

---

Chenyi Qiang (7):
  KVM: VMX: Introduce PKS VMCS fields
  KVM: VMX: Expose IA32_PKRS MSR
  KVM: MMU: Rename the pkru to pkr
  KVM: MMU: Refactor pkr_mask to cache condition
  KVM: MMU: Add support for PKS emulation
  KVM: X86: Expose PKS to guest and userspace
  KVM: VMX: Enable PKS for nested VM

 arch/x86/include/asm/kvm_host.h | 13 ++---
 arch/x86/include/asm/pkeys.h    |  1 +
 arch/x86/include/asm/vmx.h      |  6 +++
 arch/x86/kvm/cpuid.c            |  3 +-
 arch/x86/kvm/mmu.h              | 36 +++++++------
 arch/x86/kvm/mmu/mmu.c          | 78 +++++++++++++++-------------
 arch/x86/kvm/vmx/capabilities.h |  6 +++
 arch/x86/kvm/vmx/nested.c       | 38 +++++++++++++-
 arch/x86/kvm/vmx/vmcs.h         |  1 +
 arch/x86/kvm/vmx/vmcs12.c       |  2 +
 arch/x86/kvm/vmx/vmcs12.h       |  6 ++-
 arch/x86/kvm/vmx/vmx.c          | 91 +++++++++++++++++++++++++++++++--
 arch/x86/kvm/vmx/vmx.h          |  3 +-
 arch/x86/kvm/x86.c              |  9 +++-
 arch/x86/kvm/x86.h              |  6 +++
 arch/x86/mm/pkeys.c             |  6 +++
 include/linux/pkeys.h           |  4 ++
 17 files changed, 240 insertions(+), 69 deletions(-)

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2.17.1