[v2,00/31] KVM: x86: hyper-v: Fine-grained TLB flush + Direct TLB flush feature

Message

Vitaly Kuznetsov April 7, 2022, 3:56 p.m. UTC

Changes since v1:
- Move '#include "svm.h"' to PATCH10 to avoid interim build breakage through
 the series.
- Fix crash from nested_vmx_free_vcpu() when nested_release_evmcs() is
 called while 'to_hv_vcpu() == NULL'.

Original description:

Currently, KVM handles HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} requests
by flushing the whole VPID and this is sub-optimal. This series introduces
the required mechanism to make handling of these requests more 
fine-grained by flushing individual GVAs only (when requested). On this
foundation, "Direct Virtual Flush" Hyper-V feature is implemented. The 
feature allows L0 to handle Hyper-V TLB flush hypercalls directly at
L0 without the need to reflect the exit to L1. This has at least two
benefits: reflecting vmexit and the consequent vmenter are avoided + L0
has precise information whether the target vCPU is actually running (and
thus requires a kick).

Vitaly Kuznetsov (31):
  KVM: x86: hyper-v: Resurrect dedicated KVM_REQ_HV_TLB_FLUSH flag
  KVM: x86: hyper-v: Introduce TLB flush ring
  KVM: x86: hyper-v: Handle HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST{,EX} calls
    gently
  KVM: x86: hyper-v: Expose support for extended gva ranges for flush
    hypercalls
  KVM: x86: Prepare kvm_hv_flush_tlb() to handle L2's GPAs
  KVM: x86: hyper-v: Don't use sparse_set_to_vcpu_mask() in
    kvm_hv_send_ipi()
  KVM: x86: hyper-v: Create a separate ring for Direct TLB flush
  KVM: x86: hyper-v: Use preallocated buffer in 'struct kvm_vcpu_hv'
    instead of on-stack 'sparse_banks'
  KVM: nVMX: Keep track of hv_vm_id/hv_vp_id when eVMCS is in use
  KVM: nSVM: Keep track of Hyper-V hv_vm_id/hv_vp_id
  KVM: x86: Introduce .post_hv_direct_flush() nested hook
  KVM: x86: hyper-v: Introduce kvm_hv_is_tlb_flush_hcall()
  KVM: x86: hyper-v: Direct TLB flush
  KVM: x86: hyper-v: Introduce fast kvm_hv_direct_tlb_flush_exposed()
    check
  x86/hyperv: Fix 'struct hv_enlightened_vmcs' definition
  KVM: nVMX: hyper-v: Direct TLB flush
  KVM: x86: KVM_REQ_TLB_FLUSH_CURRENT is a superset of
    KVM_REQ_HV_TLB_FLUSH too
  KVM: nSVM: hyper-v: Direct TLB flush
  KVM: x86: Expose Hyper-V Direct TLB flush feature
  KVM: selftests: add hyperv_svm_test to .gitignore
  KVM: selftests: Better XMM read/write helpers
  KVM: selftests: Hyper-V PV IPI selftest
  KVM: selftests: Make it possible to replace PTEs with __virt_pg_map()
  KVM: selftests: Hyper-V PV TLB flush selftest
  KVM: selftests: Sync 'struct hv_enlightened_vmcs' definition with
    hyperv-tlfs.h
  KVM: selftests: nVMX: Allocate Hyper-V partition assist page
  KVM: selftests: nSVM: Allocate Hyper-V partition assist and VP assist
    pages
  KVM: selftests: Sync 'struct hv_vp_assist_page' definition with
    hyperv-tlfs.h
  KVM: selftests: evmcs_test: Direct TLB flush test
  KVM: selftests: Move Hyper-V VP assist page enablement out of evmcs.h
  KVM: selftests: hyperv_svm_test: Add Direct TLB flush test

 arch/x86/include/asm/hyperv-tlfs.h            |   6 +-
 arch/x86/include/asm/kvm_host.h               |  30 +
 arch/x86/kvm/Makefile                         |   3 +-
 arch/x86/kvm/hyperv.c                         | 305 ++++++++-
 arch/x86/kvm/hyperv.h                         |  55 ++
 arch/x86/kvm/svm/hyperv.c                     |  18 +
 arch/x86/kvm/svm/hyperv.h                     |  37 +
 arch/x86/kvm/svm/nested.c                     |  25 +-
 arch/x86/kvm/trace.h                          |  21 +-
 arch/x86/kvm/vmx/evmcs.c                      |  24 +
 arch/x86/kvm/vmx/evmcs.h                      |   4 +
 arch/x86/kvm/vmx/nested.c                     |  32 +
 arch/x86/kvm/x86.c                            |  15 +-
 arch/x86/kvm/x86.h                            |   1 +
 tools/testing/selftests/kvm/.gitignore        |   3 +
 tools/testing/selftests/kvm/Makefile          |   4 +-
 .../selftests/kvm/include/x86_64/evmcs.h      |  40 +-
 .../selftests/kvm/include/x86_64/hyperv.h     |  35 +
 .../selftests/kvm/include/x86_64/processor.h  |  72 +-
 .../selftests/kvm/include/x86_64/svm_util.h   |  10 +
 .../selftests/kvm/include/x86_64/vmx.h        |   4 +
 .../testing/selftests/kvm/lib/x86_64/hyperv.c |  21 +
 .../selftests/kvm/lib/x86_64/processor.c      |   6 +-
 tools/testing/selftests/kvm/lib/x86_64/svm.c  |  10 +
 tools/testing/selftests/kvm/lib/x86_64/vmx.c  |   7 +
 .../selftests/kvm/max_guest_memory_test.c     |   2 +-
 .../testing/selftests/kvm/x86_64/evmcs_test.c |  53 +-
 .../selftests/kvm/x86_64/hyperv_features.c    |   5 +-
 .../testing/selftests/kvm/x86_64/hyperv_ipi.c | 362 ++++++++++
 .../selftests/kvm/x86_64/hyperv_svm_test.c    |  60 +-
 .../selftests/kvm/x86_64/hyperv_tlb_flush.c   | 647 ++++++++++++++++++
 .../selftests/kvm/x86_64/mmu_role_test.c      |   2 +-
 32 files changed, 1797 insertions(+), 122 deletions(-)
 create mode 100644 arch/x86/kvm/svm/hyperv.c
 create mode 100644 tools/testing/selftests/kvm/lib/x86_64/hyperv.c
 create mode 100644 tools/testing/selftests/kvm/x86_64/hyperv_ipi.c
 create mode 100644 tools/testing/selftests/kvm/x86_64/hyperv_tlb_flush.c