diff options
| -rw-r--r-- | docs/hyperv.txt | 17 | ||||
| -rw-r--r-- | target/i386/cpu.c | 1 | ||||
| -rw-r--r-- | target/i386/cpu.h | 1 | ||||
| -rw-r--r-- | target/i386/kvm/kvm.c | 9 |
4 files changed, 25 insertions, 3 deletions
diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 000638a2fd..072709a68f 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -203,8 +203,11 @@ When the option is set to 'on' QEMU will always enable the feature, regardless of host setup. To keep guests secure, this can only be used in conjunction with exposing correct vCPU topology and vCPU pinning. -4. Development features -======================== +4. Supplementary features +========================= + +4.1. hv-passthrough +=================== In some cases (e.g. during development) it may make sense to use QEMU in 'pass-through' mode and give Windows guests all enlightenments currently supported by KVM. This pass-through mode is enabled by "hv-passthrough" CPU @@ -215,8 +218,16 @@ values from KVM to QEMU. "hv-passthrough" overrides all other "hv-*" settings on the command line. Also, enabling this flag effectively prevents migration as the list of enabled enlightenments may differ between target and destination hosts. +4.2. hv-enforce-cpuid +===================== +By default, KVM allows the guest to use all currently supported Hyper-V +enlightenments when Hyper-V CPUID interface was exposed, regardless of if +some features were not announced in guest visible CPUIDs. 'hv-enforce-cpuid' +feature alters this behavior and only allows the guest to use exposed Hyper-V +enlightenments. + -4. Useful links +5. Useful links ================ Hyper-V Top Level Functional specification and other information: https://github.com/MicrosoftDocs/Virtualization-Documentation diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 598019de12..2a19eba56d 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -6834,6 +6834,7 @@ static Property x86_cpu_properties[] = { DEFINE_PROP_ON_OFF_AUTO("hv-no-nonarch-coresharing", X86CPU, hyperv_no_nonarch_cs, ON_OFF_AUTO_OFF), DEFINE_PROP_BOOL("hv-passthrough", X86CPU, hyperv_passthrough, false), + DEFINE_PROP_BOOL("hv-enforce-cpuid", X86CPU, hyperv_enforce_cpuid, false), DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true), DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false), diff --git a/target/i386/cpu.h b/target/i386/cpu.h index c990150373..8a7209bbf2 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1719,6 +1719,7 @@ struct X86CPU { uint32_t hyperv_version_id[4]; uint32_t hyperv_limits[3]; uint32_t hyperv_nested[4]; + bool hyperv_enforce_cpuid; bool check_cpuid; bool enforce_cpuid; diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index d6a70c27e5..fbe6b7ac72 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -1531,6 +1531,15 @@ static int hyperv_init_vcpu(X86CPU *cpu) cpu->hyperv_nested[0] = evmcs_version; } + if (cpu->hyperv_enforce_cpuid) { + ret = kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_ENFORCE_CPUID, 0, 1); + if (ret < 0) { + error_report("failed to enable KVM_CAP_HYPERV_ENFORCE_CPUID: %s", + strerror(-ret)); + return ret; + } + } + return 0; } |