From e204ac612cb2cc1a33f4205976386d237d676319 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Mon, 22 Oct 2018 18:55:06 +0200 Subject: [PATCH] x86: hv_evmcs CPU flag support Adds a new CPU flag to enable the Enlightened VMCS KVM feature. QEMU enables KVM_CAP_HYPERV_ENLIGHTENED_VMCS and gets back the version to be advertised in lower 16 bits of CPUID.0x4000000A:EAX. Suggested-by: Ladi Prosek Signed-off-by: Vitaly Kuznetsov Message-Id: <20181022165506.30332-3-vkuznets@redhat.com> Reviewed-by: Roman Kagan Signed-off-by: Paolo Bonzini --- target/i386/cpu.c | 1 + target/i386/cpu.h | 1 + target/i386/hyperv-proto.h | 2 ++ target/i386/kvm.c | 30 ++++++++++++++++++++++++++++-- 4 files changed, 32 insertions(+), 2 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index af7e9f09cc..f81d35e1f9 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -5732,6 +5732,7 @@ static Property x86_cpu_properties[] = { DEFINE_PROP_BOOL("hv-frequencies", X86CPU, hyperv_frequencies, false), DEFINE_PROP_BOOL("hv-reenlightenment", X86CPU, hyperv_reenlightenment, false), DEFINE_PROP_BOOL("hv-tlbflush", X86CPU, hyperv_tlbflush, false), + DEFINE_PROP_BOOL("hv-evmcs", X86CPU, hyperv_evmcs, false), DEFINE_PROP_BOOL("hv-ipi", X86CPU, hyperv_ipi, 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 ad0e0b4534..9c52d0cbeb 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1391,6 +1391,7 @@ struct X86CPU { bool hyperv_frequencies; bool hyperv_reenlightenment; bool hyperv_tlbflush; + bool hyperv_evmcs; bool hyperv_ipi; bool check_cpuid; bool enforce_cpuid; diff --git a/target/i386/hyperv-proto.h b/target/i386/hyperv-proto.h index 8c572cd7c2..c0272b3a01 100644 --- a/target/i386/hyperv-proto.h +++ b/target/i386/hyperv-proto.h @@ -18,6 +18,7 @@ #define HV_CPUID_FEATURES 0x40000003 #define HV_CPUID_ENLIGHTMENT_INFO 0x40000004 #define HV_CPUID_IMPLEMENT_LIMITS 0x40000005 +#define HV_CPUID_NESTED_FEATURES 0x4000000A #define HV_CPUID_MIN 0x40000005 #define HV_CPUID_MAX 0x4000ffff #define HV_HYPERVISOR_PRESENT_BIT 0x80000000 @@ -60,6 +61,7 @@ #define HV_RELAXED_TIMING_RECOMMENDED (1u << 5) #define HV_CLUSTER_IPI_RECOMMENDED (1u << 10) #define HV_EX_PROCESSOR_MASKS_RECOMMENDED (1u << 11) +#define HV_ENLIGHTENED_VMCS_RECOMMENDED (1u << 14) /* * Basic virtualized MSRs diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 796a049a0d..f524e7d929 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -869,6 +869,7 @@ 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; @@ -912,7 +913,8 @@ int kvm_arch_init_vcpu(CPUState *cs) memset(signature, 0, 12); memcpy(signature, cpu->hyperv_vendor_id, len); } - c->eax = HV_CPUID_MIN; + c->eax = cpu->hyperv_evmcs ? + HV_CPUID_NESTED_FEATURES : HV_CPUID_IMPLEMENT_LIMITS; c->ebx = signature[0]; c->ecx = signature[1]; c->edx = signature[2]; @@ -970,7 +972,16 @@ int kvm_arch_init_vcpu(CPUState *cs) 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->ebx = cpu->hyperv_spinlock_attempts; c = &cpuid_data.entries[cpuid_i++]; @@ -981,6 +992,21 @@ int kvm_arch_init_vcpu(CPUState *cs) kvm_base = KVM_CPUID_SIGNATURE_NEXT; has_msr_hv_hypercall = true; + + if (cpu->hyperv_evmcs) { + __u32 function; + + /* Create zeroed 0x40000006..0x40000009 leaves */ + for (function = HV_CPUID_IMPLEMENT_LIMITS + 1; + function < HV_CPUID_NESTED_FEATURES; function++) { + c = &cpuid_data.entries[cpuid_i++]; + c->function = function; + } + + c = &cpuid_data.entries[cpuid_i++]; + c->function = HV_CPUID_NESTED_FEATURES; + c->eax = evmcs_version; + } } if (cpu->expose_kvm) {