From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: [PATCH 1/2] KVM: nVMX: Validate EFER values for VM_ENTRY/EXIT_LOAD_IA32_EFER Date: Sun, 14 Apr 2013 12:44:09 +0200 Message-ID: <516A8879.6050202@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: kvm , Paolo Bonzini , Nadav Har'El To: Gleb Natapov , Marcelo Tosatti Return-path: Received: from mout.web.de ([212.227.17.11]:58734 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751597Ab3DNKoP (ORCPT ); Sun, 14 Apr 2013 06:44:15 -0400 Sender: kvm-owner@vger.kernel.org List-ID: =46rom: Jan Kiszka As we may emulate the loading of EFER on VM-entry and VM-exit, implemen= t the checks that VMX performs on the guest and host values on vmlaunch/ vmresume. Factor out kvm_valid_efer for this purpose which checks for set reserved bits. Signed-off-by: Jan Kiszka --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/vmx.c | 38 +++++++++++++++++++++++++++++++= +++++++ arch/x86/kvm/x86.c | 29 +++++++++++++++++++---------- 3 files changed, 58 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm= _host.h index b2c7263..28a458f 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -805,6 +805,7 @@ static inline int emulate_instruction(struct kvm_vc= pu *vcpu, } =20 void kvm_enable_efer_bits(u64); +bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer); int kvm_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *data); int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr); =20 diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index cc2ba55..0d13b29 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -7257,6 +7257,44 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu,= bool launch) } =20 /* + * If the =93load IA32_EFER=94 VM-entry control is 1, the following c= hecks + * are performed on the field for the IA32_EFER MSR: + * - Bits reserved in the IA32_EFER MSR must be 0. + * - Bit 10 (corresponding to IA32_EFER.LMA) must equal the value of + * the IA-32e mode guest VM-exit control. It must also be identical + * to bit 8 (LME) if bit 31 in the CR0 field (corresponding to + * CR0.PG) is 1.1 + */ + if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER && + (!kvm_valid_efer(vcpu, vmcs12->guest_ia32_efer) || + !!(vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) !=3D + !!(vmcs12->guest_ia32_efer & EFER_LMA) || + (vmcs12->guest_cr0 & X86_CR0_PG && + !!(vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) !=3D + !!(vmcs12->guest_ia32_efer & EFER_LME)))) { + nested_vmx_entry_failure(vcpu, vmcs12, + EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT); + return 1; + } + + /* + * If the load IA32_EFER VM-exit control is 1, bits reserved in the + * IA32_EFER MSR must be 0 in the field for that register. In additio= n, + * the values of the LMA and LME bits in the field must each be that = of + * the host address-space size VM-exit control. + */ + if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER && + (!kvm_valid_efer(vcpu, vmcs12->host_ia32_efer) || + !!(vmcs12->vm_exit_controls & VM_EXIT_HOST_ADDR_SPACE_SIZE) !=3D + !!(vmcs12->host_ia32_efer & EFER_LMA) || + !!(vmcs12->vm_exit_controls & VM_EXIT_HOST_ADDR_SPACE_SIZE) !=3D + !!(vmcs12->host_ia32_efer & EFER_LME))) { + nested_vmx_entry_failure(vcpu, vmcs12, + EXIT_REASON_INVALID_STATE, ENTRY_FAIL_DEFAULT); + return 1; + } + + /* * We're finally done with prerequisite checking, and can start with * the nested entry. */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index eb9927e..f248a3a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -845,23 +845,17 @@ static const u32 emulated_msrs[] =3D { MSR_IA32_MCG_CTL, }; =20 -static int set_efer(struct kvm_vcpu *vcpu, u64 efer) +bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer) { - u64 old_efer =3D vcpu->arch.efer; - if (efer & efer_reserved_bits) - return 1; - - if (is_paging(vcpu) - && (vcpu->arch.efer & EFER_LME) !=3D (efer & EFER_LME)) - return 1; + return false; =20 if (efer & EFER_FFXSR) { struct kvm_cpuid_entry2 *feat; =20 feat =3D kvm_find_cpuid_entry(vcpu, 0x80000001, 0); if (!feat || !(feat->edx & bit(X86_FEATURE_FXSR_OPT))) - return 1; + return false; } =20 if (efer & EFER_SVME) { @@ -869,9 +863,24 @@ static int set_efer(struct kvm_vcpu *vcpu, u64 efe= r) =20 feat =3D kvm_find_cpuid_entry(vcpu, 0x80000001, 0); if (!feat || !(feat->ecx & bit(X86_FEATURE_SVM))) - return 1; + return false; } =20 + return true; +} +EXPORT_SYMBOL_GPL(kvm_valid_efer); + +static int set_efer(struct kvm_vcpu *vcpu, u64 efer) +{ + u64 old_efer =3D vcpu->arch.efer; + + if (!kvm_valid_efer(vcpu, efer)) + return 1; + + if (is_paging(vcpu) + && (vcpu->arch.efer & EFER_LME) !=3D (efer & EFER_LME)) + return 1; + efer &=3D ~EFER_LMA; efer |=3D vcpu->arch.efer & EFER_LMA; =20 --=20 1.7.3.4