From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> To: Liran Alon <liran.alon@oracle.com> Cc: qemu-devel@nongnu.org, pbonzini@redhat.com, mtosatti@redhat.com, rth@twiddle.net, ehabkost@redhat.com, kvm@vger.kernel.org, jmattson@google.com, maran.wilson@oracle.com Subject: Re: [QEMU PATCH v3 4/9] KVM: i386: Block migration for vCPUs exposed with nested virtualization Date: Tue, 18 Jun 2019 09:44:20 +0100 Message-ID: <20190618084420.GA2850@work-vm> (raw) In-Reply-To: <20190617175658.135869-5-liran.alon@oracle.com> * Liran Alon (liran.alon@oracle.com) wrote: > Commit d98f26073beb ("target/i386: kvm: add VMX migration blocker") > added a migration blocker for vCPU exposed with Intel VMX. > However, migration should also be blocked for vCPU exposed with > AMD SVM. > > Both cases should be blocked because QEMU should extract additional > vCPU state from KVM that should be migrated as part of vCPU VMState. > E.g. Whether vCPU is running in guest-mode or host-mode. > > Fixes: d98f26073beb ("target/i386: kvm: add VMX migration blocker") > Signed-off-by: Liran Alon <liran.alon@oracle.com> > --- > target/i386/cpu.c | 6 ------ > target/i386/cpu.h | 24 ++++++++++++++++++++++++ > target/i386/kvm.c | 12 ++++++------ > 3 files changed, 30 insertions(+), 12 deletions(-) > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > index 536d7d152044..197201087e65 100644 > --- a/target/i386/cpu.c > +++ b/target/i386/cpu.c > @@ -5170,12 +5170,6 @@ static int x86_cpu_filter_features(X86CPU *cpu) > return rv; > } > > -#define IS_INTEL_CPU(env) ((env)->cpuid_vendor1 == CPUID_VENDOR_INTEL_1 && \ > - (env)->cpuid_vendor2 == CPUID_VENDOR_INTEL_2 && \ > - (env)->cpuid_vendor3 == CPUID_VENDOR_INTEL_3) > -#define IS_AMD_CPU(env) ((env)->cpuid_vendor1 == CPUID_VENDOR_AMD_1 && \ > - (env)->cpuid_vendor2 == CPUID_VENDOR_AMD_2 && \ > - (env)->cpuid_vendor3 == CPUID_VENDOR_AMD_3) > static void x86_cpu_realizefn(DeviceState *dev, Error **errp) > { > CPUState *cs = CPU(dev); > diff --git a/target/i386/cpu.h b/target/i386/cpu.h > index fce6660bac00..79d9495ceb0c 100644 > --- a/target/i386/cpu.h > +++ b/target/i386/cpu.h > @@ -728,6 +728,13 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS]; > > #define CPUID_VENDOR_HYGON "HygonGenuine" > > +#define IS_INTEL_CPU(env) ((env)->cpuid_vendor1 == CPUID_VENDOR_INTEL_1 && \ > + (env)->cpuid_vendor2 == CPUID_VENDOR_INTEL_2 && \ > + (env)->cpuid_vendor3 == CPUID_VENDOR_INTEL_3) > +#define IS_AMD_CPU(env) ((env)->cpuid_vendor1 == CPUID_VENDOR_AMD_1 && \ > + (env)->cpuid_vendor2 == CPUID_VENDOR_AMD_2 && \ > + (env)->cpuid_vendor3 == CPUID_VENDOR_AMD_3) > + > #define CPUID_MWAIT_IBE (1U << 1) /* Interrupts can exit capability */ > #define CPUID_MWAIT_EMX (1U << 0) /* enumeration supported */ > > @@ -1866,6 +1873,23 @@ static inline int32_t x86_get_a20_mask(CPUX86State *env) > } > } > > +static inline bool cpu_has_vmx(CPUX86State *env) > +{ > + return (IS_INTEL_CPU(env) && > + (env->features[FEAT_1_ECX] & CPUID_EXT_VMX)); > +} > + > +static inline bool cpu_has_svm(CPUX86State *env) > +{ > + return (IS_AMD_CPU(env) && > + (env->features[FEAT_8000_0001_ECX] & CPUID_EXT3_SVM)); Note that the Hygon Dhyana seems to have SVM set as well, see target/i386/cpu.c and search for "Dhyana" (Note the AMD users are going to be a bit more surprised by this restriction than Intel users, since Nested has been enabled on AMD for a long time). Dave > +} > + > +static inline bool cpu_has_nested_virt(CPUX86State *env) > +{ > + return (cpu_has_vmx(env) || cpu_has_svm(env)); > +} > + > /* fpu_helper.c */ > void update_fp_status(CPUX86State *env); > void update_mxcsr_status(CPUX86State *env); > diff --git a/target/i386/kvm.c b/target/i386/kvm.c > index c8fd53055d37..f43e2d69859e 100644 > --- a/target/i386/kvm.c > +++ b/target/i386/kvm.c > @@ -906,7 +906,7 @@ static int hyperv_init_vcpu(X86CPU *cpu) > } > > static Error *invtsc_mig_blocker; > -static Error *vmx_mig_blocker; > +static Error *nested_virt_mig_blocker; > > #define KVM_MAX_CPUID_ENTRIES 100 > > @@ -1270,13 +1270,13 @@ int kvm_arch_init_vcpu(CPUState *cs) > !!(c->ecx & CPUID_EXT_SMX); > } > > - if ((env->features[FEAT_1_ECX] & CPUID_EXT_VMX) && !vmx_mig_blocker) { > - error_setg(&vmx_mig_blocker, > - "Nested VMX virtualization does not support live migration yet"); > - r = migrate_add_blocker(vmx_mig_blocker, &local_err); > + if (cpu_has_nested_virt(env) && !nested_virt_mig_blocker) { > + error_setg(&nested_virt_mig_blocker, > + "Nested virtualization does not support live migration yet"); > + r = migrate_add_blocker(nested_virt_mig_blocker, &local_err); > if (local_err) { > error_report_err(local_err); > - error_free(vmx_mig_blocker); > + error_free(nested_virt_mig_blocker); > return r; > } > } > -- > 2.20.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
next prev parent reply index Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-06-17 17:56 [QEMU PATCH v3 0/9]: KVM: i386: Add support for save and restore of nested state Liran Alon 2019-06-17 17:56 ` [QEMU PATCH v3 1/9] KVM: Introduce kvm_arch_destroy_vcpu() Liran Alon 2019-06-18 22:15 ` [Qemu-devel] " Maran Wilson 2019-06-17 17:56 ` [QEMU PATCH v3 2/9] KVM: i386: Use symbolic constant for #DB/#BP exception constants Liran Alon 2019-06-17 17:56 ` [QEMU PATCH v3 3/9] KVM: i386: Re-inject #DB to guest with updated DR6 Liran Alon 2019-06-17 17:56 ` [QEMU PATCH v3 4/9] KVM: i386: Block migration for vCPUs exposed with nested virtualization Liran Alon 2019-06-18 8:44 ` Dr. David Alan Gilbert [this message] 2019-06-18 22:16 ` [Qemu-devel] " Maran Wilson 2019-06-17 17:56 ` [QEMU PATCH v3 5/9] linux-headers: i386: Modify struct kvm_nested_state to have explicit fields for data Liran Alon 2019-06-18 22:16 ` [Qemu-devel] " Maran Wilson 2019-06-17 17:56 ` [QEMU PATCH v3 6/9] vmstate: Add support for kernel integer types Liran Alon 2019-06-18 8:55 ` Dr. David Alan Gilbert 2019-06-18 15:36 ` Liran Alon 2019-06-18 15:42 ` Dr. David Alan Gilbert 2019-06-18 16:44 ` Paolo Bonzini 2019-06-17 17:56 ` [QEMU PATCH v3 7/9] KVM: i386: Add support for save and restore nested state Liran Alon 2019-06-18 9:03 ` Dr. David Alan Gilbert 2019-06-18 15:40 ` Liran Alon 2019-06-18 15:48 ` Dr. David Alan Gilbert 2019-06-18 15:50 ` Liran Alon 2019-06-18 16:16 ` Paolo Bonzini 2019-06-18 22:16 ` [Qemu-devel] " Maran Wilson 2019-06-17 17:56 ` [QEMU PATCH v3 8/9] KVM: i386: Add support for KVM_CAP_EXCEPTION_PAYLOAD Liran Alon 2019-06-18 9:07 ` Dr. David Alan Gilbert 2019-06-18 15:45 ` Liran Alon 2019-06-17 17:56 ` [QEMU PATCH v3 9/9] KVM: i386: Remove VMX migration blocker Liran Alon 2019-06-18 22:17 ` [Qemu-devel] " Maran Wilson
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