From 071ce4b03becf9e2df6b758fde9609be8ddf56f1 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Tue, 8 Jun 2021 14:08:13 +0200 Subject: [PATCH] i386: expand Hyper-V features during CPU feature expansion time To make Hyper-V features appear in e.g. QMP query-cpu-model-expansion we need to expand and set the corresponding CPUID leaves early. Modify x86_cpu_get_supported_feature_word() to call newly intoduced Hyper-V specific kvm_hv_get_supported_cpuid() instead of kvm_arch_get_supported_cpuid(). We can't use kvm_arch_get_supported_cpuid() as Hyper-V specific CPUID leaves intersect with KVM's. Note, early expansion will only happen when KVM supports system wide KVM_GET_SUPPORTED_HV_CPUID ioctl (KVM_CAP_SYS_HYPERV_CPUID). Reviewed-by: Eduardo Habkost Signed-off-by: Vitaly Kuznetsov Message-Id: <20210608120817.1325125-6-vkuznets@redhat.com> Signed-off-by: Eduardo Habkost --- target/i386/cpu.c | 4 ++++ target/i386/kvm/kvm-stub.c | 5 +++++ target/i386/kvm/kvm.c | 24 ++++++++++++++++++++---- target/i386/kvm/kvm_i386.h | 1 + 4 files changed, 30 insertions(+), 4 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 5f595a0d7e..46befde387 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -5974,6 +5974,10 @@ void x86_cpu_expand_features(X86CPU *cpu, Error **errp) if (env->cpuid_xlevel2 == UINT32_MAX) { env->cpuid_xlevel2 = env->cpuid_min_xlevel2; } + + if (kvm_enabled()) { + kvm_hyperv_expand_features(cpu, errp); + } } /* diff --git a/target/i386/kvm/kvm-stub.c b/target/i386/kvm/kvm-stub.c index 92f49121b8..f6e7e4466e 100644 --- a/target/i386/kvm/kvm-stub.c +++ b/target/i386/kvm/kvm-stub.c @@ -39,3 +39,8 @@ bool kvm_hv_vpindex_settable(void) { return false; } + +bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp) +{ + abort(); +} diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index ef127762bc..556815db13 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -1220,13 +1220,22 @@ static uint32_t hv_build_cpuid_leaf(CPUState *cs, uint32_t func, int reg) * of 'hv_passthrough' mode and fills the environment with all supported * Hyper-V features. */ -static bool hyperv_expand_features(CPUState *cs, Error **errp) +bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp) { - X86CPU *cpu = X86_CPU(cs); + CPUState *cs = CPU(cpu); if (!hyperv_enabled(cpu)) return true; + /* + * When kvm_hyperv_expand_features is called at CPU feature expansion + * time per-CPU kvm_state is not available yet so we can only proceed + * when KVM_CAP_SYS_HYPERV_CPUID is supported. + */ + if (!cs->kvm_state && + !kvm_check_extension(kvm_state, KVM_CAP_SYS_HYPERV_CPUID)) + return true; + if (cpu->hyperv_passthrough) { cpu->hyperv_vendor_id[0] = hv_cpuid_get_host(cs, HV_CPUID_VENDOR_AND_MAX_FUNCTIONS, R_EBX); @@ -1593,8 +1602,15 @@ int kvm_arch_init_vcpu(CPUState *cs) env->apic_bus_freq = KVM_APIC_BUS_FREQUENCY; - /* Paravirtualization CPUIDs */ - if (!hyperv_expand_features(cs, &local_err)) { + /* + * kvm_hyperv_expand_features() is called here for the second time in case + * KVM_CAP_SYS_HYPERV_CPUID is not supported. While we can't possibly handle + * 'query-cpu-model-expansion' in this case as we don't have a KVM vCPU to + * check which Hyper-V enlightenments are supported and which are not, we + * can still proceed and check/expand Hyper-V enlightenments here so legacy + * behavior is preserved. + */ + if (!kvm_hyperv_expand_features(cpu, &local_err)) { error_report_err(local_err); return -ENOSYS; } diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h index dc72508389..54667b35f0 100644 --- a/target/i386/kvm/kvm_i386.h +++ b/target/i386/kvm/kvm_i386.h @@ -47,6 +47,7 @@ bool kvm_has_x2apic_api(void); bool kvm_has_waitpkg(void); bool kvm_hv_vpindex_settable(void); +bool kvm_hyperv_expand_features(X86CPU *cpu, Error **errp); uint64_t kvm_swizzle_msi_ext_dest_id(uint64_t address);