[PATCH v4 00/19] i386: KVM: expand Hyper-V features early and provide simple 'hv-default=on' option

[Vitaly Kuznetsov]

Changes since v3:
- Make 'hv-default' override 'hv-*' options which were already set 
  (e.g. 'hv-feature=on,hv-default' case) [Igor]. Make 'hv-passthrough'
  behave the same way.
- Add "i386: be more picky about implicit 'hv-evmcs' enablement" patch to avoid
  enabling 'hv-evmcs' with hv-default/hv-passthrough when guest CPU lacks VMX.
- Add "i386: support 'hv-passthrough,hv-feature=off' on the command line" patch
  to make 'hv-passthrough' semantics match the newly introduced 'hv-default'.
- Add "i386: track explicit 'hv-*' features enablement/disablement" patch to
  support the above mentioned changes.
- Expand qtest to check the above mentioned improvements.

Original description:

Upper layer tools like libvirt want to figure out which Hyper-V features are
supported by the underlying stack (QEMU/KVM) but currently they are unable to
do so. We have a nice 'hv_passthrough' CPU flag supported by QEMU but it has
no effect on e.g. QMP's 

query-cpu-model-expansion type=full 
model={"name":"host","props":{"hv-passthrough":true}}

command as we parse Hyper-V features after creating KVM vCPUs and not at
feature expansion time. To support the use-case we first need to make 
KVM_GET_SUPPORTED_HV_CPUID ioctl a system-wide ioctl as the existing
vCPU version can't be used that early. This is what KVM part does. With
that done, we can make early Hyper-V feature expansion (this series).

In addition, provide a simple 'hv-default' option which enables (and
requires from KVM) all currently supported Hyper-V enlightenments.
Unlike 'hv-passthrough' mode, this is going to be migratable.

Vitaly Kuznetsov (21):
  i386: keep hyperv_vendor string up-to-date
  i386: invert hyperv_spinlock_attempts setting logic with
    hv_passthrough
  i386: always fill Hyper-V CPUID feature leaves from X86CPU data
  i386: stop using env->features[] for filling Hyper-V CPUIDs
  i386: introduce hyperv_feature_supported()
  i386: introduce hv_cpuid_get_host()
  i386: drop FEAT_HYPERV feature leaves
  i386: introduce hv_cpuid_cache
  i386: split hyperv_handle_properties() into
    hyperv_expand_features()/hyperv_fill_cpuids()
  i386: move eVMCS enablement to hyperv_init_vcpu()
  i386: switch hyperv_expand_features() to using error_setg()
  i386: adjust the expected KVM_GET_SUPPORTED_HV_CPUID array size
  i386: prefer system KVM_GET_SUPPORTED_HV_CPUID ioctl over vCPU's one
  i386: use global kvm_state in hyperv_enabled() check
  i386: expand Hyper-V features during CPU feature expansion time
  i386: track explicit 'hv-*' features enablement/disablement
  i386: support 'hv-passthrough,hv-feature=off' on the command line
  i386: be more picky about implicit 'hv-evmcs' enablement
  i386: introduce kvm_hv_evmcs_available()
  i386: provide simple 'hv-default=on' option
  qtest/hyperv: Introduce a simple hyper-v test

 MAINTAINERS                |   1 +
 docs/hyperv.txt            |  16 +-
 target/i386/cpu.c          | 430 ++++++++++++++++++++---------
 target/i386/cpu.h          |  11 +-
 target/i386/kvm/kvm-stub.c |  10 +
 target/i386/kvm/kvm.c      | 535 +++++++++++++++++++++----------------
 target/i386/kvm/kvm_i386.h |   2 +
 tests/qtest/hyperv-test.c  | 312 +++++++++++++++++++++
 tests/qtest/meson.build    |   3 +-
 9 files changed, 950 insertions(+), 370 deletions(-)
 create mode 100644 tests/qtest/hyperv-test.c

-- 
2.29.2