From patchwork Thu Sep 29 17:20:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 12994477 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1D3CC433F5 for ; Thu, 29 Sep 2022 17:20:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235911AbiI2RUX (ORCPT ); Thu, 29 Sep 2022 13:20:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235273AbiI2RUV (ORCPT ); Thu, 29 Sep 2022 13:20:21 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8BF91023AB for ; Thu, 29 Sep 2022 10:20:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1664472020; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HcFaK80T9K557/Wa2SaUlDPQ+F2xISZ2hAqyCg9mPNE=; b=KFOi7qmN3Mj+fe+u338d2uLCKpNgMLX5g1ZMaaU59qP9rdqi/7IJY4U5EMnnlpCb+8D2lC Ad4nukHWITBYK1xed93N4zEIgEXpAsztkTL7RCYe4TbbSrzgpYaKXd01LUquY7/8n1XnB2 b/R1fYbGsmw6TSOycJLAbREkVRUpgq8= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-669-Ph4mfmYNPUCgI8fiTCxsVw-1; Thu, 29 Sep 2022 13:20:18 -0400 X-MC-Unique: Ph4mfmYNPUCgI8fiTCxsVw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DB6D829324AA; Thu, 29 Sep 2022 17:20:17 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id B4AC742220; Thu, 29 Sep 2022 17:20:17 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: seanjc@google.com, maciej.szmigiero@oracle.com Subject: [PATCH v2 5/8] KVM: allow compiling out SMM support Date: Thu, 29 Sep 2022 13:20:13 -0400 Message-Id: <20220929172016.319443-6-pbonzini@redhat.com> In-Reply-To: <20220929172016.319443-1-pbonzini@redhat.com> References: <20220929172016.319443-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Some users of KVM implement the UEFI variable store through a paravirtual device that does not require the "SMM lockbox" component of edk2; allow them to compile out system management mode, which is not a full implementation especially in how it interacts with nested virtualization. Suggested-by: Sean Christopherson Signed-off-by: Paolo Bonzini Reviewed-by: Maxim Levitsky --- arch/x86/kvm/Kconfig | 11 ++++++++++ arch/x86/kvm/Makefile | 2 +- arch/x86/kvm/smm.h | 13 ++++++++++++ arch/x86/kvm/svm/svm.c | 2 ++ arch/x86/kvm/vmx/vmx.c | 2 ++ arch/x86/kvm/x86.c | 21 +++++++++++++++++-- tools/testing/selftests/kvm/x86_64/smm_test.c | 2 ++ 7 files changed, 50 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index a107df22ffee..1679f9b4e96d 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -88,6 +88,17 @@ config KVM_INTEL To compile this as a module, choose M here: the module will be called kvm-intel. +config KVM_SMM + bool "System Management Mode emulation" + default y + depends on KVM + help + Provides support for KVM to emulate System Management Mode (SMM) + in virtual machines. This can be used by the virtual machine + firmware to implement UEFI secure boot. + + If unsure, say Y. + config X86_SGX_KVM bool "Software Guard eXtensions (SGX) Virtualization" depends on X86_SGX && KVM_INTEL diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile index ec6f7656254b..6cf40f668277 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -20,7 +20,7 @@ endif kvm-$(CONFIG_X86_64) += mmu/tdp_iter.o mmu/tdp_mmu.o kvm-$(CONFIG_KVM_XEN) += xen.o -kvm-y += smm.o +kvm-$(CONFIG_KVM_SMM) += smm.o kvm-intel-y += vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o \ vmx/evmcs.o vmx/nested.o vmx/posted_intr.o diff --git a/arch/x86/kvm/smm.h b/arch/x86/kvm/smm.h index b0602a92e511..4c699fee4492 100644 --- a/arch/x86/kvm/smm.h +++ b/arch/x86/kvm/smm.h @@ -8,6 +8,7 @@ #define PUT_SMSTATE(type, buf, offset, val) \ *(type *)((buf) + (offset) - 0x7e00) = val +#ifdef CONFIG_KVM_SMM static inline int kvm_inject_smi(struct kvm_vcpu *vcpu) { kvm_make_request(KVM_REQ_SMI, vcpu); @@ -23,5 +24,17 @@ void kvm_smm_changed(struct kvm_vcpu *vcpu, bool in_smm); void enter_smm(struct kvm_vcpu *vcpu); int emulator_leave_smm(struct x86_emulate_ctxt *ctxt); void process_smi(struct kvm_vcpu *vcpu); +#else +static inline int kvm_inject_smi(struct kvm_vcpu *vcpu) { return -ENOTTY; } +static inline bool is_smm(struct kvm_vcpu *vcpu) { return false; } +static inline void kvm_smm_changed(struct kvm_vcpu *vcpu, bool in_smm) { WARN_ON_ONCE(1); } +static inline void enter_smm(struct kvm_vcpu *vcpu) { WARN_ON_ONCE(1); } +static inline void process_smi(struct kvm_vcpu *vcpu) { WARN_ON_ONCE(1); } + +/* + * emulator_leave_smm is used as a function pointer, so the + * stub is defined in x86.c. + */ +#endif #endif diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 496ee7d1ae2f..6f7ceb35d2ff 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4150,6 +4150,8 @@ static bool svm_has_emulated_msr(struct kvm *kvm, u32 index) case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC: return false; case MSR_IA32_SMBASE: + if (!IS_ENABLED(CONFIG_KVM_SMM)) + return false; /* SEV-ES guests do not support SMM, so report false */ if (kvm && sev_es_guest(kvm)) return false; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 038809c68006..b22330a15adb 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6841,6 +6841,8 @@ static bool vmx_has_emulated_msr(struct kvm *kvm, u32 index) { switch (index) { case MSR_IA32_SMBASE: + if (!IS_ENABLED(CONFIG_KVM_SMM)) + return false; /* * We cannot do SMM unless we can run the guest in big * real mode. diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 97a871635986..a9e050aefea6 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3636,7 +3636,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; } case MSR_IA32_SMBASE: - if (!msr_info->host_initiated) + if (!IS_ENABLED(CONFIG_KVM_SMM) || !msr_info->host_initiated) return 1; vcpu->arch.smbase = data; break; @@ -4052,7 +4052,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = vcpu->arch.ia32_misc_enable_msr; break; case MSR_IA32_SMBASE: - if (!msr_info->host_initiated) + if (!IS_ENABLED(CONFIG_KVM_SMM) || !msr_info->host_initiated) return 1; msr_info->data = vcpu->arch.smbase; break; @@ -4426,6 +4426,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r |= KVM_X86_DISABLE_EXITS_MWAIT; break; case KVM_CAP_X86_SMM: + if (!IS_ENABLED(CONFIG_KVM_SMM)) + break; + /* SMBASE is usually relocated above 1M on modern chipsets, * and SMM handlers might indeed rely on 4G segment limits, * so do not report SMM to be available if real mode is @@ -5176,6 +5179,12 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, vcpu->arch.apic->sipi_vector = events->sipi_vector; if (events->flags & KVM_VCPUEVENT_VALID_SMM) { + if (!IS_ENABLED(CONFIG_KVM_SMM) && + (events->smi.smm || + events->smi.pending || + events->smi.smm_inside_nmi)) + return -EINVAL; + if (!!(vcpu->arch.hflags & HF_SMM_MASK) != events->smi.smm) { kvm_x86_ops.nested_ops->leave_nested(vcpu); kvm_smm_changed(vcpu, events->smi.smm); @@ -8066,6 +8075,14 @@ static unsigned emulator_get_hflags(struct x86_emulate_ctxt *ctxt) return emul_to_vcpu(ctxt)->arch.hflags; } +#ifndef CONFIG_KVM_SMM +static int emulator_leave_smm(struct x86_emulate_ctxt *ctxt) +{ + WARN_ON_ONCE(1); + return X86EMUL_UNHANDLEABLE; +} +#endif + static void emulator_triple_fault(struct x86_emulate_ctxt *ctxt) { kvm_make_request(KVM_REQ_TRIPLE_FAULT, emul_to_vcpu(ctxt)); diff --git a/tools/testing/selftests/kvm/x86_64/smm_test.c b/tools/testing/selftests/kvm/x86_64/smm_test.c index 1f136a81858e..cb38a478e1f6 100644 --- a/tools/testing/selftests/kvm/x86_64/smm_test.c +++ b/tools/testing/selftests/kvm/x86_64/smm_test.c @@ -137,6 +137,8 @@ int main(int argc, char *argv[]) struct kvm_x86_state *state; int stage, stage_reported; + TEST_REQUIRE(kvm_has_cap(KVM_CAP_X86_SMM)); + /* Create VM */ vm = vm_create_with_one_vcpu(&vcpu, guest_code);