| Message ID | 20231205103630.1391318-9-vkuznets@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: Make Hyper-V emulation optional | expand |
On Tue, 2023-12-05 at 11:36 +0100, Vitaly Kuznetsov wrote: > To avoid overloading handle_vmclear() with Hyper-V specific details and to > prepare the code to making Hyper-V emulation optional, create a dedicated > nested_evmcs_handle_vmclear() helper. > > No functional change intended. > > Suggested-by: Sean Christopherson <seanjc@google.com> > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> > --- > arch/x86/kvm/vmx/nested.c | 38 ++++++++++++++++++++++++-------------- > 1 file changed, 24 insertions(+), 14 deletions(-) > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 382c0746d069..903b6f9ea2bd 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -243,6 +243,29 @@ static inline void nested_release_evmcs(struct kvm_vcpu *vcpu) > } > } > > +static bool nested_evmcs_handle_vmclear(struct kvm_vcpu *vcpu, gpa_t vmptr) > +{ > + struct vcpu_vmx *vmx = to_vmx(vcpu); > + /* > + * When Enlightened VMEntry is enabled on the calling CPU we treat > + * memory area pointer by vmptr as Enlightened VMCS (as there's no good > + * way to distinguish it from VMCS12) and we must not corrupt it by > + * writing to the non-existent 'launch_state' field. The area doesn't > + * have to be the currently active EVMCS on the calling CPU and there's > + * nothing KVM has to do to transition it from 'active' to 'non-active' > + * state. It is possible that the area will stay mapped as > + * vmx->nested.hv_evmcs but this shouldn't be a problem. > + */ > + if (!guest_cpuid_has_evmcs(vcpu) || > + !evmptr_is_valid(nested_get_evmptr(vcpu))) > + return false; > + > + if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr) > + nested_release_evmcs(vcpu); > + > + return true; > +} > + > static void vmx_sync_vmcs_host_state(struct vcpu_vmx *vmx, > struct loaded_vmcs *prev) > { > @@ -5286,18 +5309,7 @@ static int handle_vmclear(struct kvm_vcpu *vcpu) > if (vmptr == vmx->nested.vmxon_ptr) > return nested_vmx_fail(vcpu, VMXERR_VMCLEAR_VMXON_POINTER); > > - /* > - * When Enlightened VMEntry is enabled on the calling CPU we treat > - * memory area pointer by vmptr as Enlightened VMCS (as there's no good > - * way to distinguish it from VMCS12) and we must not corrupt it by > - * writing to the non-existent 'launch_state' field. The area doesn't > - * have to be the currently active EVMCS on the calling CPU and there's > - * nothing KVM has to do to transition it from 'active' to 'non-active' > - * state. It is possible that the area will stay mapped as > - * vmx->nested.hv_evmcs but this shouldn't be a problem. > - */ > - if (likely(!guest_cpuid_has_evmcs(vcpu) || > - !evmptr_is_valid(nested_get_evmptr(vcpu)))) { > + if (likely(!nested_evmcs_handle_vmclear(vcpu, vmptr))) { > if (vmptr == vmx->nested.current_vmptr) > nested_release_vmcs12(vcpu); > > @@ -5314,8 +5326,6 @@ static int handle_vmclear(struct kvm_vcpu *vcpu) > vmptr + offsetof(struct vmcs12, > launch_state), > &zero, sizeof(zero)); > - } else if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr) { > - nested_release_evmcs(vcpu); > } > > return nested_vmx_succeed(vcpu); Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Best regards, Maxim Levitsky
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 382c0746d069..903b6f9ea2bd 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -243,6 +243,29 @@ static inline void nested_release_evmcs(struct kvm_vcpu *vcpu) } } +static bool nested_evmcs_handle_vmclear(struct kvm_vcpu *vcpu, gpa_t vmptr) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + /* + * When Enlightened VMEntry is enabled on the calling CPU we treat + * memory area pointer by vmptr as Enlightened VMCS (as there's no good + * way to distinguish it from VMCS12) and we must not corrupt it by + * writing to the non-existent 'launch_state' field. The area doesn't + * have to be the currently active EVMCS on the calling CPU and there's + * nothing KVM has to do to transition it from 'active' to 'non-active' + * state. It is possible that the area will stay mapped as + * vmx->nested.hv_evmcs but this shouldn't be a problem. + */ + if (!guest_cpuid_has_evmcs(vcpu) || + !evmptr_is_valid(nested_get_evmptr(vcpu))) + return false; + + if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr) + nested_release_evmcs(vcpu); + + return true; +} + static void vmx_sync_vmcs_host_state(struct vcpu_vmx *vmx, struct loaded_vmcs *prev) { @@ -5286,18 +5309,7 @@ static int handle_vmclear(struct kvm_vcpu *vcpu) if (vmptr == vmx->nested.vmxon_ptr) return nested_vmx_fail(vcpu, VMXERR_VMCLEAR_VMXON_POINTER); - /* - * When Enlightened VMEntry is enabled on the calling CPU we treat - * memory area pointer by vmptr as Enlightened VMCS (as there's no good - * way to distinguish it from VMCS12) and we must not corrupt it by - * writing to the non-existent 'launch_state' field. The area doesn't - * have to be the currently active EVMCS on the calling CPU and there's - * nothing KVM has to do to transition it from 'active' to 'non-active' - * state. It is possible that the area will stay mapped as - * vmx->nested.hv_evmcs but this shouldn't be a problem. - */ - if (likely(!guest_cpuid_has_evmcs(vcpu) || - !evmptr_is_valid(nested_get_evmptr(vcpu)))) { + if (likely(!nested_evmcs_handle_vmclear(vcpu, vmptr))) { if (vmptr == vmx->nested.current_vmptr) nested_release_vmcs12(vcpu); @@ -5314,8 +5326,6 @@ static int handle_vmclear(struct kvm_vcpu *vcpu) vmptr + offsetof(struct vmcs12, launch_state), &zero, sizeof(zero)); - } else if (vmx->nested.hv_evmcs && vmptr == vmx->nested.hv_evmcs_vmptr) { - nested_release_evmcs(vcpu); } return nested_vmx_succeed(vcpu);
To avoid overloading handle_vmclear() with Hyper-V specific details and to prepare the code to making Hyper-V emulation optional, create a dedicated nested_evmcs_handle_vmclear() helper. No functional change intended. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- arch/x86/kvm/vmx/nested.c | 38 ++++++++++++++++++++++++-------------- 1 file changed, 24 insertions(+), 14 deletions(-)