Changes since v6 [Eduardo]: - First 14 patches of v6 made it upstream! - New patches addressing feedback on the already merged patches added: i386: make hyperv_expand_features() return bool i386: hardcode supported eVMCS version to '1' i386: clarify 'hv-passthrough' behavior i386: avoid hardcoding '12' as 'hyperv_vendor_id' length - Some comments expanded. - HV_HYPERCALL_AVAILABLE setting moved to hyperv_fill_cpuids()
Note: Windows guest on QEMU are currently completely broken, see Claudio's https://lore.kernel.org/kvm/20210529091313.16708-1-cfont...@suse.de/ The last two functional patches are inspired by 'Fine-grained access check to Hyper-V hypercalls and MSRs' work for KVM: https://lore.kernel.org/kvm/20210521095204.2161214-1-vkuzn...@redhat.com/ 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). Vitaly Kuznetsov (9): i386: avoid hardcoding '12' as 'hyperv_vendor_id' length i386: clarify 'hv-passthrough' behavior i386: hardcode supported eVMCS version to '1' i386: make hyperv_expand_features() return bool i386: expand Hyper-V features during CPU feature expansion time i386: kill off hv_cpuid_check_and_set() i386: HV_HYPERCALL_AVAILABLE privilege bit is always needed i386: Hyper-V SynIC requires POST_MESSAGES/SIGNAL_EVENTS priviliges qtest/hyperv: Introduce a simple hyper-v test MAINTAINERS | 1 + docs/hyperv.txt | 9 +- target/i386/cpu.c | 13 +- target/i386/kvm/hyperv-proto.h | 6 + target/i386/kvm/kvm-stub.c | 5 + target/i386/kvm/kvm.c | 166 ++++++++++++------------ target/i386/kvm/kvm_i386.h | 1 + tests/qtest/hyperv-test.c | 225 +++++++++++++++++++++++++++++++++ tests/qtest/meson.build | 3 +- 9 files changed, 337 insertions(+), 92 deletions(-) create mode 100644 tests/qtest/hyperv-test.c -- 2.31.1