[PATCH v2 0/8] KVM: VMX: Add full nested support for IA32_PERF_GLOBAL_CTRL

[Oliver Upton <oupton@google.com>]

[v1] https://lore.kernel.org/r/20190828234134.132704-1-oupton@google.com

v1 => v2:
 - Add Krish's Co-developed-by and Signed-off-by tags.
 - Fix minor nit to kvm-unit-tests to use 'host' local variable
   throughout test_load_pgc()
 - Teach guest_state_test_main() to check guest state from within nested
   VM
 - Update proposed tests to use guest/host state checks, wherein the
   value is checked from MSR_CORE_PERF_GLOBAL_CTRL.
 - Changelog line wrapping

This patchset exposes the "load IA32_PERF_GLOBAL_CTRL" to guests for nested
VM-entry and VM-exit. There already was some existing code that supported
the VM-exit ctrl, though it had an issue and was not exposed to the guest
anyway. These patches are based on the original set that Krish Sadhukhan
sent out earlier this year.

Purpose of each patch:

(1) Change the existing code that implemented the VM-exit functionality
    to use kvm_set_msr() to avoid being overwritten by
    atomic_perf_switch_msrs().
(2) Update prepare_vmcs02() to implement the VM-entry functionality,
    again using kvm_set_msr().
(3) Create a helper function for checking the validity of an
    IA32_PERF_GLOBAL_CTRL value against pmu->global_ctrl_mask.
(4) Check guest state on VM-entry as described in the SDM.
(5) Check host state on VM-entry as described in the SDM.
(6) Expose the "load IA32_PERF_GLOBAL_CTRL" VM-entry and VM-exit
    controls if IA32_PERF_GLOBAL_CTRL is a valid MSR.
(7) Modify guest_state_test_main() to check guest state MSRs
(8) Tests in kvm-unit-tests to check the VM-entry and VM-exit controls
    work properly

Oliver Upton (6):
  KVM: nVMX: Use kvm_set_msr to load IA32_PERF_GLOBAL_CTRL on vmexit
  KVM: nVMX: Load GUEST_IA32_PERF_GLOBAL_CTRL MSR on vm-entry
  KVM: VMX: Add helper to check reserved bits in IA32_PERF_GLOBAL_CTRL
  KVM: nVMX: check GUEST_IA32_PERF_GLOBAL_CTRL on VM-Entry
  KVM: nVMX: Check HOST_IA32_PERF_GLOBAL_CTRL on VM-entry
  KVM: nVMX: Expose load IA32_PERF_GLOBAL_CTRL vm control if supported

 arch/x86/kvm/pmu.h           |  6 ++++++
 arch/x86/kvm/vmx/nested.c    | 37 +++++++++++++++++++++++++++++++++---
 arch/x86/kvm/vmx/pmu_intel.c |  5 ++++-
 arch/x86/kvm/vmx/vmx.c       | 21 ++++++++++++++++++++
 arch/x86/kvm/vmx/vmx.h       |  1 +
 5 files changed, 66 insertions(+), 4 deletions(-)

-- 
2.23.0.187.g17f5b7556c-goog