[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH RFC 22/22] i386: expand Hyper-V features early
From: |
Eduardo Habkost |
Subject: |
Re: [PATCH RFC 22/22] i386: expand Hyper-V features early |
Date: |
Fri, 18 Sep 2020 18:38:20 -0400 |
On Fri, Sep 04, 2020 at 04:54:31PM +0200, Vitaly Kuznetsov wrote:
> 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).
Will this implicitly enable hyperv CPUID passthrough when using
"-cpu host"? Do we want it to?
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
> target/i386/cpu.c | 15 +++++++++------
> target/i386/kvm.c | 15 +++++++++++++++
> target/i386/kvm_i386.h | 7 +++++++
> 3 files changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 479c4bbbf459..d3c4ecb3535c 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -5147,7 +5147,7 @@ CpuDefinitionInfoList *qmp_query_cpu_definitions(Error
> **errp)
> return cpu_list;
> }
>
> -static uint64_t x86_cpu_get_supported_feature_word(FeatureWord w,
> +static uint64_t x86_cpu_get_supported_feature_word(X86CPU *cpu, FeatureWord
> w,
> bool migratable_only)
> {
> FeatureWordInfo *wi = &feature_word_info[w];
> @@ -5156,9 +5156,12 @@ static uint64_t
> x86_cpu_get_supported_feature_word(FeatureWord w,
> if (kvm_enabled()) {
> switch (wi->type) {
> case CPUID_FEATURE_WORD:
> - r = kvm_arch_get_supported_cpuid(kvm_state, wi->cpuid.eax,
> - wi->cpuid.ecx,
> - wi->cpuid.reg);
> + if (hyperv_feature_word(w))
> + r = kvm_hv_get_supported_cpuid(cpu, w);
> + else
> + r = kvm_arch_get_supported_cpuid(kvm_state, wi->cpuid.eax,
> + wi->cpuid.ecx,
> + wi->cpuid.reg);
> break;
> case MSR_FEATURE_WORD:
> r = kvm_arch_get_supported_msr_feature(kvm_state,
> @@ -6485,7 +6488,7 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error
> **errp)
> * by the user.
> */
> env->features[w] |=
> - x86_cpu_get_supported_feature_word(w, cpu->migratable) &
> + x86_cpu_get_supported_feature_word(cpu, w, cpu->migratable) &
> ~env->user_features[w] &
> ~feature_word_info[w].no_autoenable_flags;
> }
> @@ -6589,7 +6592,7 @@ static void x86_cpu_filter_features(X86CPU *cpu, bool
> verbose)
>
> for (w = 0; w < FEATURE_WORDS; w++) {
> uint64_t host_feat =
> - x86_cpu_get_supported_feature_word(w, false);
> + x86_cpu_get_supported_feature_word(cpu, w, false);
> uint64_t requested_features = env->features[w];
> uint64_t unavailable_features = requested_features & ~host_feat;
> mark_unavailable_features(cpu, w, unavailable_features, prefix);
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index 961241528a5c..764b96fbbb7d 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -1449,6 +1449,21 @@ static int hyperv_fill_cpuids(CPUState *cs,
> return cpuid_i;
> }
>
> +uint32_t kvm_hv_get_supported_cpuid(X86CPU *cpu, enum FeatureWord w)
> +{
> + CPUState *cs = CPU(cpu);
> + CPUX86State *env = &cpu->env;
> + Error *local_err = NULL;
> +
> + hyperv_expand_features(cs, &local_err);
> +
> + if (local_err) {
> + error_report_err(local_err);
> + }
> +
> + return env->features[w];
> +}
> +
> static Error *hv_passthrough_mig_blocker;
> static Error *hv_no_nonarch_cs_mig_blocker;
>
> diff --git a/target/i386/kvm_i386.h b/target/i386/kvm_i386.h
> index 064b8798a26c..2e7da4f39668 100644
> --- a/target/i386/kvm_i386.h
> +++ b/target/i386/kvm_i386.h
> @@ -48,4 +48,11 @@ bool kvm_has_waitpkg(void);
>
> bool kvm_hv_vpindex_settable(void);
>
> +static inline bool hyperv_feature_word(enum FeatureWord w)
> +{
> + return w >= FEAT_HYPERV_EAX && w <= FEAT_HV_NESTED_EDX;
> +}
> +
> +uint32_t kvm_hv_get_supported_cpuid(X86CPU *cpu, enum FeatureWord w);
> +
> #endif
> --
> 2.25.4
>
--
Eduardo
- [PATCH RFC 09/22] i386: add reserved FEAT_HYPERV_ECX CPUID leaf, (continued)
- [PATCH RFC 09/22] i386: add reserved FEAT_HYPERV_ECX CPUID leaf, Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 13/22] i386: split hyperv_handle_properties() into hyperv_expand_features()/hyperv_fill_cpuids(), Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 12/22] i386: always fill Hyper-V CPUID feature leaves from X86CPU data, Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 15/22] i386: switch hyperv_expand_features() to using error_setg(), Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 18/22] i386: prefer system KVM_GET_SUPPORTED_HV_CPUID ioctl over vCPU's one, Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 22/22] i386: expand Hyper-V features early, Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 21/22] i386: record if Hyper-V features were already expanded, Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 19/22] i386: prepare hyperv_expand_features() to be called at CPU feature expansion time, Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 16/22] i386: make hyperv_expand_features() return void, Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 17/22] i386: adjust the expected KVM_GET_SUPPORTED_HV_CPUID array size, Vitaly Kuznetsov, 2020/09/04
- [PATCH RFC 20/22] i386: use global kvm_state in hyperv_enabled() check, Vitaly Kuznetsov, 2020/09/04