[RFC,00/22] i386: KVM: expand Hyper-V features early

Message

Vitaly Kuznetsov Sept. 4, 2020, 2:54 p.m. UTC

This pairs with https://lore.kernel.org/kvm/[e-mail]/
and as KVM part is not yet accepted, sending this as RFC.

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).

Vitaly Kuznetsov (22):
  WIP: update linux/headers
  i386: drop x86_cpu_get_supported_feature_word() forward declaration
  i386: move hyperv_vendor_id initialization to x86_cpu_realizefn()
  i386: move hyperv_interface_id initialization to x86_cpu_realizefn()
  i386: move hyperv_version_id initialization to x86_cpu_realizefn()
  i386: move hyperv_limits initialization to x86_cpu_realizefn()
  i386: fill in FEAT_HYPERV_EDX from edx instead of eax
  i386: invert hyperv_spinlock_attempts setting logic with
    hv_passthrough
  i386: add reserved FEAT_HYPERV_ECX CPUID leaf
  i386: add reserved FEAT_HV_RECOMM_ECX/FEAT_HV_RECOMM_EDX CPUID leaves
  i386: add reserved FEAT_HV_NESTED_EBX/ECX/EDX CPUID leaves
  i386: always fill Hyper-V CPUID feature leaves from X86CPU data
  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: make hyperv_expand_features() return void
  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: prepare hyperv_expand_features() to be called at CPU feature
    expansion time
  i386: use global kvm_state in hyperv_enabled() check
  i386: record if Hyper-V features were already expanded
  i386: expand Hyper-V features early

 include/standard-headers/drm/drm_fourcc.h     | 140 +++++++
 include/standard-headers/linux/ethtool.h      |  87 +++++
 .../linux/input-event-codes.h                 |   3 +-
 linux-headers/asm-generic/unistd.h            |   6 +-
 linux-headers/asm-mips/unistd_n32.h           |   1 +
 linux-headers/asm-mips/unistd_n64.h           |   1 +
 linux-headers/asm-mips/unistd_o32.h           |   1 +
 linux-headers/asm-powerpc/kvm.h               |   5 +
 linux-headers/asm-powerpc/mman.h              |   2 +-
 linux-headers/asm-powerpc/unistd_32.h         |   1 +
 linux-headers/asm-powerpc/unistd_64.h         |   1 +
 linux-headers/asm-s390/kvm.h                  |   7 +-
 linux-headers/asm-s390/unistd_32.h            |   1 +
 linux-headers/asm-s390/unistd_64.h            |   1 +
 linux-headers/asm-x86/unistd_32.h             |   1 +
 linux-headers/asm-x86/unistd_64.h             |   1 +
 linux-headers/asm-x86/unistd_x32.h            |   1 +
 linux-headers/linux/kvm.h                     |   7 +-
 linux-headers/linux/vfio.h                    |   2 +-
 target/i386/cpu.c                             |  78 +++-
 target/i386/cpu.h                             |  13 +-
 target/i386/kvm.c                             | 347 ++++++++++++------
 target/i386/kvm_i386.h                        |   7 +
 23 files changed, 579 insertions(+), 135 deletions(-)