public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Yang Zhong <yang.zhong@intel.com>,
	x86@kernel.org, Jim Mattson <jmattson@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	Wanpeng Li <wanpengli@tencent.com>, Shuah Khan <shuah@kernel.org>,
	Guang Zeng <guang.zeng@intel.com>, Joerg Roedel <joro@8bytes.org>,
	Maxim Levitsky <mlevitsk@redhat.com>,
	linux-kernel@vger.kernel.org,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Ingo Molnar <mingo@redhat.com>,
	linux-kselftest@vger.kernel.org,
	Kees Cook <keescook@chromium.org>,
	"H. Peter Anvin" <hpa@zytor.com>, Wei Wang <wei.w.wang@intel.com>,
	Borislav Petkov <bp@alien8.de>
Subject: [PATCH RESEND v4 05/23] KVM: allow compiling out SMM support
Date: Tue, 25 Oct 2022 15:47:23 +0300	[thread overview]
Message-ID: <20221025124741.228045-6-mlevitsk@redhat.com> (raw)
In-Reply-To: <20221025124741.228045-1-mlevitsk@redhat.com>

From: Paolo Bonzini <pbonzini@redhat.com>

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 <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 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 67be7f217e37bd..716becc0df45b4 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -87,6 +87,17 @@ 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 ec6f7656254b9f..6cf40f66827776 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 b0602a92e511e1..4c699fee449296 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 496ee7d1ae2fb7..6f7ceb35d2ff08 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 038809c6800601..b22330a15adb63 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 2ae8ac525fc324..6c81d3a606e257 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3649,7 +3649,7 @@ 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;
@@ -4065,7 +4065,7 @@ 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;
@@ -4439,6 +4439,9 @@ 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
@@ -5189,6 +5192,12 @@ 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);
@@ -8079,6 +8088,14 @@ 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 1f136a81858e5d..cb38a478e1f62a 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);
 
-- 
2.34.3


  parent reply	other threads:[~2022-10-25 12:51 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-25 12:47 [PATCH RESEND v4 00/23] SMM emulation and interrupt shadow fixes Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 01/23] KVM: x86: start moving SMM-related functions to new files Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 02/23] KVM: x86: move SMM entry to a new file Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 03/23] KVM: x86: move SMM exit " Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 04/23] KVM: x86: do not go through ctxt->ops when emulating rsm Maxim Levitsky
2022-10-25 12:47 ` Maxim Levitsky [this message]
2022-10-25 12:47 ` [PATCH RESEND v4 06/23] KVM: x86: compile out vendor-specific code if SMM is disabled Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 07/23] KVM: x86: remove SMRAM address space if SMM is not supported Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 08/23] KVM: x86: do not define KVM_REQ_SMI if SMM disabled Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 09/23] bug: introduce ASSERT_STRUCT_OFFSET Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 10/23] KVM: x86: emulator: em_sysexit should update ctxt->mode Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 11/23] KVM: x86: emulator: introduce emulator_recalc_and_set_mode Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 12/23] KVM: x86: emulator: update the emulation mode after rsm Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 13/23] KVM: x86: emulator: update the emulation mode after CR0 write Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 14/23] KVM: x86: smm: number of GPRs in the SMRAM image depends on the image format Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 15/23] KVM: x86: smm: check for failures on smm entry Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 16/23] KVM: x86: smm: add structs for KVM's smram layout Maxim Levitsky
2022-10-28 13:34   ` Paolo Bonzini
2022-10-25 12:47 ` [PATCH RESEND v4 17/23] KVM: x86: smm: use smram structs in the common code Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 18/23] KVM: x86: smm: use smram struct for 32 bit smram load/restore Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 19/23] KVM: x86: smm: use smram struct for 64 " Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 20/23] KVM: svm: drop explicit return value of kvm_vcpu_map Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 21/23] KVM: x86: SVM: use smram structs Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 22/23] KVM: x86: SVM: don't save SVM state to SMRAM when VM is not long mode capable Maxim Levitsky
2022-10-25 12:47 ` [PATCH RESEND v4 23/23] KVM: x86: smm: preserve interrupt shadow in SMRAM Maxim Levitsky
2022-10-28 10:35   ` Paolo Bonzini
2022-10-30  8:23     ` Maxim Levitsky
2022-10-27 16:49 ` [PATCH RESEND v4 00/23] SMM emulation and interrupt shadow fixes Paolo Bonzini
2022-10-27 17:06   ` Maxim Levitsky
2022-10-28 10:36     ` Paolo Bonzini
2022-10-28 22:42       ` Sean Christopherson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20221025124741.228045-6-mlevitsk@redhat.com \
    --to=mlevitsk@redhat.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=guang.zeng@intel.com \
    --cc=hpa@zytor.com \
    --cc=jmattson@google.com \
    --cc=joro@8bytes.org \
    --cc=keescook@chromium.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=seanjc@google.com \
    --cc=shuah@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=vkuznets@redhat.com \
    --cc=wanpengli@tencent.com \
    --cc=wei.w.wang@intel.com \
    --cc=x86@kernel.org \
    --cc=yang.zhong@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox