diff mbox series

[v10,103/108] KVM: TDX: Silently discard SMI request

Message ID	e8b5a458f0944d2945d53c4a42d927e1979129f7.1667110240.git.isaku.yamahata@intel.com
State	New
Headers	Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; From: isaku.yamahata@intel.com To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Paolo Bonzini <pbonzini@redhat.com>, erdemaktas@google.com, Sean Christopherson <seanjc@google.com>, Sagi Shahar <sagis@google.com>, David Matlack <dmatlack@google.com> Subject: [PATCH v10 103/108] KVM: TDX: Silently discard SMI request Date: Sat, 29 Oct 2022 23:23:44 -0700 Message-Id: <e8b5a458f0944d2945d53c4a42d927e1979129f7.1667110240.git.isaku.yamahata@intel.com> In-Reply-To: <cover.1667110240.git.isaku.yamahata@intel.com> References: <cover.1667110240.git.isaku.yamahata@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	KVM TDX basic feature support \| [v10,000/108] KVM TDX basic feature support [v10,001/108] KVM: VMX: Move out vmx_x86_ops to 'main.c' to wrap VMX and TDX [v10,002/108] KVM: x86: Refactor KVM VMX module init/exit functions [v10,003/108] KVM: TDX: Add placeholders for TDX VM/vcpu structure [v10,004/108] x86/virt/tdx: Add a helper function to return system wide info about TDX module [v10,005/108] KVM: TDX: Initialize the TDX module when loading the KVM intel kernel module [v10,006/108] KVM: x86: Introduce vm_type to differentiate default VMs from confidential VMs [v10,007/108] KVM: TDX: Make TDX VM type supported [v10,008/108,MARKER] The start of TDX KVM patch series: TDX architectural definitions [v10,009/108] KVM: TDX: Define TDX architectural definitions [v10,010/108] KVM: TDX: Add TDX "architectural" error codes [v10,011/108] KVM: TDX: Add C wrapper functions for SEAMCALLs to the TDX module [v10,012/108] KVM: TDX: Add helper functions to print TDX SEAMCALL error [v10,013/108,MARKER] The start of TDX KVM patch series: TD VM creation/destruction [v10,014/108] KVM: TDX: Stub in tdx.h with structs, accessors, and VMCS helpers [v10,015/108] x86/cpu: Add helper functions to allocate/free TDX private host key id [v10,016/108] KVM: TDX: create/destroy VM structure [v10,017/108] KVM: TDX: Refuse to unplug the last cpu on the package [v10,018/108] KVM: TDX: x86: Add ioctl to get TDX systemwide parameters [v10,019/108] KVM: TDX: Add place holder for TDX VM specific mem_enc_op ioctl [v10,020/108] KVM: Support KVM_CAP_MAX_VCPUS for KVM_ENABLE_CAP [v10,021/108] KVM: TDX: initialize VM with TDX specific parameters [v10,022/108] KVM: TDX: Make pmu_intel.c ignore guest TD case [v10,023/108,MARKER] The start of TDX KVM patch series: TD vcpu creation/destruction [v10,024/108] KVM: TDX: allocate/free TDX vcpu structure [v10,025/108] KVM: TDX: Do TDX specific vcpu initialization [v10,026/108] KVM: TDX: Use private memory for TDX [v10,027/108,MARKER] The start of TDX KVM patch series: KVM MMU GPA shared bits [v10,028/108] KVM: x86/mmu: introduce config for PRIVATE KVM MMU [v10,029/108] KVM: x86/mmu: Add address conversion functions for TDX shared bit of GPA [v10,030/108,MARKER] The start of TDX KVM patch series: KVM TDP refactoring for TDX [v10,031/108] KVM: x86/mmu: Replace hardcoded value 0 for the initial value for SPTE [v10,032/108] KVM: x86/mmu: Make sync_page not use hard-coded 0 as the initial SPTE value [v10,033/108] KVM: x86/mmu: Allow non-zero value for non-present SPTE and removed SPTE [v10,034/108] KVM: x86/mmu: Add Suppress VE bit to shadow_mmio_{value, mask} [v10,035/108] KVM: x86/mmu: Track shadow MMIO value on a per-VM basis [v10,036/108] KVM: TDX: Enable mmio spte caching always for TDX [v10,037/108] KVM: x86/mmu: Disallow fast page fault on private GPA [v10,038/108] KVM: x86/mmu: Allow per-VM override of the TDP max page level [v10,039/108] KVM: VMX: Introduce test mode related to EPT violation VE [v10,040/108,MARKER] The start of TDX KVM patch series: KVM TDP MMU hooks [v10,041/108] KVM: x86/tdp_mmu: refactor kvm_tdp_mmu_map() [v10,042/108] KVM: x86/tdp_mmu: Init role member of struct kvm_mmu_page at allocation [v10,043/108] KVM: x86/mmu: Require TDP MMU for TDX [v10,044/108] KVM: x86/mmu: Add a new is_private member for union kvm_mmu_page_role [v10,045/108] KVM: x86/mmu: Add a private pointer to struct kvm_mmu_page [v10,046/108] KVM: Add flags to struct kvm_gfn_range [v10,047/108] KVM: x86/tdp_mmu: Don't zap private pages for unsupported cases [v10,048/108] KVM: x86/tdp_mmu: Make handle_changed_spte() return value [v10,049/108] KVM: x86/tdp_mmu: Support TDX private mapping for TDP MMU [v10,050/108,MARKER] The start of TDX KVM patch series: TDX EPT violation [v10,051/108] KVM: x86/mmu: Disallow dirty logging for x86 TDX [v10,052/108] KVM: x86/tdp_mmu: Ignore unsupported mmu operation on private GFNs [v10,053/108] KVM: VMX: Split out guts of EPT violation to common/exposed function [v10,054/108] KVM: VMX: Move setting of EPT MMU masks to common VT-x code [v10,055/108] KVM: TDX: Add load_mmu_pgd method for TDX [v10,056/108] KVM: TDX: don't request KVM_REQ_APIC_PAGE_RELOAD [v10,057/108] KVM: x86/VMX: introduce vmx tlb_remote_flush and tlb_remote_flush_with_range [v10,058/108] KVM: TDX: TDP MMU TDX support [v10,059/108,MARKER] The start of TDX KVM patch series: KVM TDP MMU MapGPA [v10,060/108] KVM: Add functions to set GFN to private or shared [v10,061/108] KVM: x86/mmu: Introduce kvm_mmu_map_tdp_page() for use by TDX [v10,062/108] KVM: x86/tdp_mmu: implement MapGPA hypercall for TDX [v10,063/108,MARKER] The start of TDX KVM patch series: TD finalization [v10,064/108] KVM: TDX: Create initial guest memory [v10,065/108] KVM: TDX: Finalize VM initialization [v10,066/108,MARKER] The start of TDX KVM patch series: TD vcpu enter/exit [v10,067/108] KVM: TDX: Add helper assembly function to TDX vcpu [v10,068/108] KVM: TDX: Implement TDX vcpu enter/exit path [v10,069/108] KVM: TDX: vcpu_run: save/restore host state(host kernel gs) [v10,070/108] KVM: TDX: restore host xsave state when exit from the guest TD [v10,071/108] KVM: x86: Allow to update cached values in kvm_user_return_msrs w/o wrmsr [v10,072/108] KVM: TDX: restore user ret MSRs [v10,073/108,MARKER] The start of TDX KVM patch series: TD vcpu exits/interrupts/hypercalls [v10,074/108] KVM: TDX: complete interrupts after tdexit [v10,075/108] KVM: TDX: restore debug store when TD exit [v10,076/108] KVM: TDX: handle vcpu migration over logical processor [v10,077/108] KVM: x86: Add a switch_db_regs flag to handle TDX's auto-switched behavior [v10,078/108] KVM: TDX: Add support for find pending IRQ in a protected local APIC [v10,079/108] KVM: x86: Assume timer IRQ was injected if APIC state is proteced [v10,080/108] KVM: TDX: remove use of struct vcpu_vmx from posted_interrupt.c [v10,081/108] KVM: TDX: Implement interrupt injection [v10,082/108] KVM: TDX: Implements vcpu request_immediate_exit [v10,083/108] KVM: TDX: Implement methods to inject NMI [v10,084/108] KVM: VMX: Modify NMI and INTR handlers to take intr_info as function argument [v10,085/108] KVM: VMX: Move NMI/exception handler to common helper [v10,086/108] KVM: x86: Split core of hypercall emulation to helper function [v10,087/108] KVM: TDX: Add a place holder to handle TDX VM exit [v10,088/108] KVM: TDX: Retry seamcall when TDX_OPERAND_BUSY with operand SEPT [v10,089/108] KVM: TDX: handle EXIT_REASON_OTHER_SMI [v10,090/108] KVM: TDX: handle ept violation/misconfig exit [v10,091/108] KVM: TDX: handle EXCEPTION_NMI and EXTERNAL_INTERRUPT [v10,092/108] KVM: TDX: Add a place holder for handler of TDX hypercalls (TDG.VP.VMCALL) [v10,093/108] KVM: TDX: handle KVM hypercall with TDG.VP.VMCALL [v10,094/108] KVM: TDX: Handle TDX PV CPUID hypercall [v10,095/108] KVM: TDX: Handle TDX PV HLT hypercall [v10,096/108] KVM: TDX: Handle TDX PV port io hypercall [v10,097/108] KVM: TDX: Handle TDX PV MMIO hypercall [v10,098/108] KVM: TDX: Implement callbacks for MSR operations for TDX [v10,099/108] KVM: TDX: Handle TDX PV rdmsr/wrmsr hypercall [v10,100/108] KVM: TDX: Handle TDX PV report fatal error hypercall [v10,101/108] KVM: TDX: Handle TDX PV map_gpa hypercall [v10,102/108] KVM: TDX: Handle TDG.VP.VMCALL<GetTdVmCallInfo> hypercall [v10,103/108] KVM: TDX: Silently discard SMI request [v10,104/108] KVM: TDX: Silently ignore INIT/SIPI [v10,105/108] KVM: TDX: Add methods to ignore accesses to CPU state [v10,106/108] Documentation/virt/kvm: Document on Trust Domain Extensions(TDX) [v10,107/108] KVM: x86: design documentation on TDX support of x86 KVM TDP MMU [v10,108/108,MARKER] the end of (the first phase of) TDX KVM patch series

Commit Message

Isaku Yamahata Oct. 30, 2022, 6:23 a.m. UTC

  From: Isaku Yamahata <isaku.yamahata@intel.com>

TDX doesn't support system-management mode (SMM) and system-management
interrupt (SMI) in guest TDs.  Because guest state (vcpu state, memory
state) is protected, it must go through the TDX module APIs to change guest
state, injecting SMI and changing vcpu mode into SMM.  The TDX module
doesn't provide a way for VMM to inject SMI into guest TD and a way for VMM
to switch guest vcpu mode into SMM.

We have two options in KVM when handling SMM or SMI in the guest TD or the
device model (e.g. QEMU): 1) silently ignore the request or 2) return a
meaningful error.

For simplicity, we implemented the option 1).

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/kvm/lapic.c       |  7 +++++--
 arch/x86/kvm/vmx/main.c    | 43 ++++++++++++++++++++++++++++++++++----
 arch/x86/kvm/vmx/tdx.c     | 27 ++++++++++++++++++++++++
 arch/x86/kvm/vmx/x86_ops.h |  8 +++++++
 arch/x86/kvm/x86.c         |  3 ++-
 5 files changed, 81 insertions(+), 7 deletions(-)

diff mbox series

Patch

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 8d894c3959c8..7a1d612bd138 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1171,8 +1171,11 @@  static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 
 	case APIC_DM_SMI:
 		result = 1;
-		kvm_make_request(KVM_REQ_SMI, vcpu);
-		kvm_vcpu_kick(vcpu);
+		if (static_call(kvm_x86_has_emulated_msr)(vcpu->kvm,
+							  MSR_IA32_SMBASE)) {
+			kvm_make_request(KVM_REQ_SMI, vcpu);
+			kvm_vcpu_kick(vcpu);
+		}
 		break;
 
 	case APIC_DM_NMI:
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 3a8a4fdf1ce7..4acba8d8cb27 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -223,6 +223,41 @@  static int vt_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	return vmx_get_msr(vcpu, msr_info);
 }
 
+static int vt_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
+{
+	if (is_td_vcpu(vcpu))
+		return tdx_smi_allowed(vcpu, for_injection);
+
+	return vmx_smi_allowed(vcpu, for_injection);
+}
+
+static int vt_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
+{
+	if (unlikely(is_td_vcpu(vcpu)))
+		return tdx_enter_smm(vcpu, smstate);
+
+	return vmx_enter_smm(vcpu, smstate);
+}
+
+static int vt_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
+{
+	if (unlikely(is_td_vcpu(vcpu)))
+		return tdx_leave_smm(vcpu, smstate);
+
+	return vmx_leave_smm(vcpu, smstate);
+}
+
+static void vt_enable_smi_window(struct kvm_vcpu *vcpu)
+{
+	if (is_td_vcpu(vcpu)) {
+		tdx_enable_smi_window(vcpu);
+		return;
+	}
+
+	/* RSM will cause a vmexit anyway.  */
+	vmx_enable_smi_window(vcpu);
+}
+
 static void vt_apicv_post_state_restore(struct kvm_vcpu *vcpu)
 {
 	struct pi_desc *pi = vcpu_to_pi_desc(vcpu);
@@ -580,10 +615,10 @@  struct kvm_x86_ops vt_x86_ops __initdata = {
 
 	.setup_mce = vmx_setup_mce,
 
-	.smi_allowed = vmx_smi_allowed,
-	.enter_smm = vmx_enter_smm,
-	.leave_smm = vmx_leave_smm,
-	.enable_smi_window = vmx_enable_smi_window,
+	.smi_allowed = vt_smi_allowed,
+	.enter_smm = vt_enter_smm,
+	.leave_smm = vt_leave_smm,
+	.enable_smi_window = vt_enable_smi_window,
 
 	.can_emulate_instruction = vmx_can_emulate_instruction,
 	.apic_init_signal_blocked = vmx_apic_init_signal_blocked,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 8e8ac1081ce4..111027724e06 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1660,6 +1660,33 @@  int tdx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 	return 1;
 }
 
+int tdx_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
+{
+	/* SMI isn't supported for TDX. */
+	WARN_ON_ONCE(1);
+	return false;
+}
+
+int tdx_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
+{
+	/* smi_allowed() is always false for TDX as above. */
+	WARN_ON_ONCE(1);
+	return 0;
+}
+
+int tdx_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
+{
+	WARN_ON_ONCE(1);
+	return 0;
+}
+
+void tdx_enable_smi_window(struct kvm_vcpu *vcpu)
+{
+	/* SMI isn't supported for TDX.  Silently discard SMI request. */
+	WARN_ON_ONCE(1);
+	vcpu->arch.smi_pending = false;
+}
+
 int tdx_dev_ioctl(void __user *argp)
 {
 	struct kvm_tdx_capabilities __user *user_caps;
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 8b9399b154f3..d4ffbf580bc5 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -165,6 +165,10 @@  void tdx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason,
 bool tdx_is_emulated_msr(u32 index, bool write);
 int tdx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr);
 int tdx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr);
+int tdx_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection);
+int tdx_enter_smm(struct kvm_vcpu *vcpu, char *smstate);
+int tdx_leave_smm(struct kvm_vcpu *vcpu, const char *smstate);
+void tdx_enable_smi_window(struct kvm_vcpu *vcpu);
 
 int tdx_vm_ioctl(struct kvm *kvm, void __user *argp);
 int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp);
@@ -206,6 +210,10 @@  static inline void tdx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason, u64 *in
 static inline bool tdx_is_emulated_msr(u32 index, bool write) { return false; }
 static inline int tdx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) { return 1; }
 static inline int tdx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) { return 1; }
+static inline int tdx_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection) { return false; }
+static inline int tdx_enter_smm(struct kvm_vcpu *vcpu, char *smstate) { return 0; }
+static inline int tdx_leave_smm(struct kvm_vcpu *vcpu, const char *smstate) { return 0; }
+static inline void tdx_enable_smi_window(struct kvm_vcpu *vcpu) {}
 
 static inline int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { return -EOPNOTSUPP; }
 static inline int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) { return -EOPNOTSUPP; }
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5304b27f2566..d07563d0e204 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4936,7 +4936,8 @@  static int kvm_vcpu_ioctl_nmi(struct kvm_vcpu *vcpu)
 
 static int kvm_vcpu_ioctl_smi(struct kvm_vcpu *vcpu)
 {
-	kvm_make_request(KVM_REQ_SMI, vcpu);
+	if (static_call(kvm_x86_has_emulated_msr)(vcpu->kvm, MSR_IA32_SMBASE))
+		kvm_make_request(KVM_REQ_SMI, vcpu);
 
 	return 0;
 }