From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48588) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gSJQp-00019C-4V for qemu-devel@nongnu.org; Thu, 29 Nov 2018 05:20:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gSJQl-0006Tu-3y for qemu-devel@nongnu.org; Thu, 29 Nov 2018 05:20:27 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53268) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gSJQj-0006SD-7D for qemu-devel@nongnu.org; Thu, 29 Nov 2018 05:20:21 -0500 References: <20181126135958.20956-1-vkuznets@redhat.com> From: Paolo Bonzini Message-ID: Date: Thu, 29 Nov 2018 11:20:14 +0100 MIME-Version: 1.0 In-Reply-To: <20181126135958.20956-1-vkuznets@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] i386/kvm: expose HV_CPUID_ENLIGHTMENT_INFO.EAX and HV_CPUID_NESTED_FEATURES.EAX as feature words List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vitaly Kuznetsov , qemu-devel@nongnu.org Cc: Richard Henderson , Eduardo Habkost , Marcelo Tosatti , Roman Kagan On 26/11/18 14:59, Vitaly Kuznetsov wrote: > It was found that QMP users of QEMU (e.g. libvirt) may need > HV_CPUID_ENLIGHTMENT_INFO.EAX/HV_CPUID_NESTED_FEATURES.EAX information. In > particular, 'hv_tlbflush' and 'hv_evmcs' enlightenments are only exposed in > HV_CPUID_ENLIGHTMENT_INFO.EAX. > > HV_CPUID_NESTED_FEATURES.EAX is exposed for two reasons: convenience > (we don't need to export it from hyperv_handle_properties() and as > future-proof for Enlightened MSR-Bitmap, PV EPT invalidation and > direct virtual flush features. > > Signed-off-by: Vitaly Kuznetsov Can you add a comment to feature_word_info, explaining why the feat_names are not set? Thanks, Paolo > --- > target/i386/cpu.c | 30 +++++++++++++++++ > target/i386/cpu.h | 2 ++ > target/i386/kvm.c | 85 +++++++++++++++++++++++++---------------------- > 3 files changed, 77 insertions(+), 40 deletions(-) > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > index f81d35e1f9..8306670e09 100644 > --- a/target/i386/cpu.c > +++ b/target/i386/cpu.c > @@ -980,6 +980,36 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { > }, > .cpuid = { .eax = 0x40000003, .reg = R_EDX, }, > }, > + [FEAT_HV_RECOMM_EAX] = { > + .type = CPUID_FEATURE_WORD, > + .feat_names = { > + NULL /* hv_recommend_pv_as_switch */, > + NULL /* hv_recommend_pv_tlbflush_local */, > + NULL /* hv_recommend_pv_tlbflush_remote */, > + NULL /* hv_recommend_msr_apic_access */, > + NULL /* hv_recommend_msr_reset */, > + NULL /* hv_recommend_relaxed_timing */, > + NULL /* hv_recommend_dma_remapping */, > + NULL /* hv_recommend_int_remapping */, > + NULL /* hv_recommend_x2apic_msrs */, > + NULL /* hv_recommend_autoeoi_deprecation */, > + NULL /* hv_recommend_pv_ipi */, > + NULL /* hv_recommend_ex_hypercalls */, > + NULL /* hv_hypervisor_is_nested */, > + NULL /* hv_recommend_int_mbec */, > + NULL /* hv_recommend_evmcs */, > + NULL, > + NULL, NULL, NULL, NULL, > + NULL, NULL, NULL, NULL, > + NULL, NULL, NULL, NULL, > + NULL, NULL, NULL, NULL, > + }, > + .cpuid = { .eax = 0x40000004, .reg = R_EAX, }, > + }, > + [FEAT_HV_NESTED_EAX] = { > + .type = CPUID_FEATURE_WORD, > + .cpuid = { .eax = 0x4000000A, .reg = R_EAX, }, > + }, > [FEAT_SVM] = { > .type = CPUID_FEATURE_WORD, > .feat_names = { > diff --git a/target/i386/cpu.h b/target/i386/cpu.h > index 9c52d0cbeb..dd881510ac 100644 > --- a/target/i386/cpu.h > +++ b/target/i386/cpu.h > @@ -497,6 +497,8 @@ typedef enum FeatureWord { > FEAT_HYPERV_EAX, /* CPUID[4000_0003].EAX */ > FEAT_HYPERV_EBX, /* CPUID[4000_0003].EBX */ > FEAT_HYPERV_EDX, /* CPUID[4000_0003].EDX */ > + FEAT_HV_RECOMM_EAX, /* CPUID[4000_0004].EAX */ > + FEAT_HV_NESTED_EAX, /* CPUID[4000_000A].EAX */ > FEAT_SVM, /* CPUID[8000_000A].EDX */ > FEAT_XSAVE, /* CPUID[EAX=0xd,ECX=1].EAX */ > FEAT_6_EAX, /* CPUID[6].EAX */ > diff --git a/target/i386/kvm.c b/target/i386/kvm.c > index f524e7d929..b4d2b40a40 100644 > --- a/target/i386/kvm.c > +++ b/target/i386/kvm.c > @@ -797,6 +797,48 @@ static int hyperv_handle_properties(CPUState *cs) > } > env->features[FEAT_HYPERV_EAX] |= HV_SYNTIMERS_AVAILABLE; > } > + if (cpu->hyperv_relaxed_timing) { > + env->features[FEAT_HV_RECOMM_EAX] |= HV_RELAXED_TIMING_RECOMMENDED; > + } > + if (cpu->hyperv_vapic) { > + env->features[FEAT_HV_RECOMM_EAX] |= HV_APIC_ACCESS_RECOMMENDED; > + } > + if (cpu->hyperv_tlbflush) { > + if (kvm_check_extension(cs->kvm_state, > + KVM_CAP_HYPERV_TLBFLUSH) <= 0) { > + fprintf(stderr, "Hyper-V TLB flush support " > + "(requested by 'hv-tlbflush' cpu flag) " > + " is not supported by kernel\n"); > + return -ENOSYS; > + } > + env->features[FEAT_HV_RECOMM_EAX] |= HV_REMOTE_TLB_FLUSH_RECOMMENDED; > + env->features[FEAT_HV_RECOMM_EAX] |= HV_EX_PROCESSOR_MASKS_RECOMMENDED; > + } > + if (cpu->hyperv_ipi) { > + if (kvm_check_extension(cs->kvm_state, > + KVM_CAP_HYPERV_SEND_IPI) <= 0) { > + fprintf(stderr, "Hyper-V IPI send support " > + "(requested by 'hv-ipi' cpu flag) " > + " is not supported by kernel\n"); > + return -ENOSYS; > + } > + env->features[FEAT_HV_RECOMM_EAX] |= HV_CLUSTER_IPI_RECOMMENDED; > + env->features[FEAT_HV_RECOMM_EAX] |= HV_EX_PROCESSOR_MASKS_RECOMMENDED; > + } > + if (cpu->hyperv_evmcs) { > + uint16_t evmcs_version; > + > + if (kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_ENLIGHTENED_VMCS, 0, > + (uintptr_t)&evmcs_version)) { > + fprintf(stderr, "Hyper-V Enlightened VMCS " > + "(requested by 'hv-evmcs' cpu flag) " > + "is not supported by kernel\n"); > + return -ENOSYS; > + } > + env->features[FEAT_HV_RECOMM_EAX] |= HV_ENLIGHTENED_VMCS_RECOMMENDED; > + env->features[FEAT_HV_NESTED_EAX] = evmcs_version; > + } > + > return 0; > } > > @@ -869,7 +911,6 @@ int kvm_arch_init_vcpu(CPUState *cs) > uint32_t unused; > struct kvm_cpuid_entry2 *c; > uint32_t signature[3]; > - uint16_t evmcs_version; > int kvm_base = KVM_CPUID_SIGNATURE; > int r; > Error *local_err = NULL; > @@ -944,44 +985,8 @@ int kvm_arch_init_vcpu(CPUState *cs) > > c = &cpuid_data.entries[cpuid_i++]; > c->function = HV_CPUID_ENLIGHTMENT_INFO; > - if (cpu->hyperv_relaxed_timing) { > - c->eax |= HV_RELAXED_TIMING_RECOMMENDED; > - } > - if (cpu->hyperv_vapic) { > - c->eax |= HV_APIC_ACCESS_RECOMMENDED; > - } > - if (cpu->hyperv_tlbflush) { > - if (kvm_check_extension(cs->kvm_state, > - KVM_CAP_HYPERV_TLBFLUSH) <= 0) { > - fprintf(stderr, "Hyper-V TLB flush support " > - "(requested by 'hv-tlbflush' cpu flag) " > - " is not supported by kernel\n"); > - return -ENOSYS; > - } > - c->eax |= HV_REMOTE_TLB_FLUSH_RECOMMENDED; > - c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED; > - } > - if (cpu->hyperv_ipi) { > - if (kvm_check_extension(cs->kvm_state, > - KVM_CAP_HYPERV_SEND_IPI) <= 0) { > - fprintf(stderr, "Hyper-V IPI send support " > - "(requested by 'hv-ipi' cpu flag) " > - " is not supported by kernel\n"); > - return -ENOSYS; > - } > - c->eax |= HV_CLUSTER_IPI_RECOMMENDED; > - c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED; > - } > - if (cpu->hyperv_evmcs) { > - if (kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_ENLIGHTENED_VMCS, 0, > - (uintptr_t)&evmcs_version)) { > - fprintf(stderr, "Hyper-V Enlightened VMCS " > - "(requested by 'hv-evmcs' cpu flag) " > - "is not supported by kernel\n"); > - return -ENOSYS; > - } > - c->eax |= HV_ENLIGHTENED_VMCS_RECOMMENDED; > - } > + > + c->eax = env->features[FEAT_HV_RECOMM_EAX]; > c->ebx = cpu->hyperv_spinlock_attempts; > > c = &cpuid_data.entries[cpuid_i++]; > @@ -1005,7 +1010,7 @@ int kvm_arch_init_vcpu(CPUState *cs) > > c = &cpuid_data.entries[cpuid_i++]; > c->function = HV_CPUID_NESTED_FEATURES; > - c->eax = evmcs_version; > + c->eax = env->features[FEAT_HV_NESTED_EAX]; > } > } > >