[v18,090/121] KVM: TDX: handle ept violation/misconfig exit

Message ID	62a4a92cf2c0d112de775129d0a592459fe778d1.1705965635.git.isaku.yamahata@intel.com (mailing list archive)
State	New, archived
Headers	show Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 79C2B679F5; Mon, 22 Jan 2024 23:55:56 +0000 (UTC) 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>, Kai Huang <kai.huang@intel.com>, chen.bo@intel.com, hang.yuan@intel.com, tina.zhang@intel.com Subject: [PATCH v18 090/121] KVM: TDX: handle ept violation/misconfig exit Date: Mon, 22 Jan 2024 15:54:06 -0800 Message-Id: <62a4a92cf2c0d112de775129d0a592459fe778d1.1705965635.git.isaku.yamahata@intel.com> In-Reply-To: <cover.1705965634.git.isaku.yamahata@intel.com> References: <cover.1705965634.git.isaku.yamahata@intel.com> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	KVM TDX basic feature support \| expand [v18,000/121] KVM TDX basic feature support [v18,001/121] x86/virt/tdx: Export TDX KeyID information [v18,002/121] x86/virt/tdx: Export SEAMCALL functions [v18,003/121] KVM: x86: Add is_vm_type_supported callback [v18,004/121] KVM: VMX: Move out vmx_x86_ops to 'main.c' to wrap VMX and TDX [v18,005/121] KVM: x86/vmx: initialize loaded_vmcss_on_cpu in vmx_hardware_setup() [v18,006/121] KVM: x86/vmx: Refactor KVM VMX module init/exit functions [v18,007/121] KVM: VMX: Reorder vmx initialization with kvm vendor initialization [v18,008/121] KVM: TDX: Initialize the TDX module when loading the KVM intel kernel module [v18,009/121] KVM: TDX: Add placeholders for TDX VM/vcpu structure [v18,010/121] KVM: TDX: Make TDX VM type supported [v18,011/121,MARKER] The start of TDX KVM patch series: TDX architectural definitions [v18,012/121] KVM: TDX: Define TDX architectural definitions [v18,013/121] KVM: TDX: Add TDX "architectural" error codes [v18,014/121] KVM: TDX: Add C wrapper functions for SEAMCALLs to the TDX module [v18,015/121] KVM: TDX: Retry SEAMCALL on the lack of entropy error [v18,016/121] KVM: TDX: Add helper functions to print TDX SEAMCALL error [v18,017/121,MARKER] The start of TDX KVM patch series: TD VM creation/destruction [v18,018/121] KVM: TDX: Add helper functions to allocate/free TDX private host key id [v18,019/121] KVM: TDX: Add helper function to read TDX metadata in array [v18,020/121] x86/virt/tdx: Get system-wide info about TDX module on initialization [v18,021/121] KVM: TDX: Add place holder for TDX VM specific mem_enc_op ioctl [v18,022/121] KVM: TDX: x86: Add ioctl to get TDX systemwide parameters [v18,023/121] KVM: TDX: Make KVM_CAP_MAX_VCPUS backend specific [v18,024/121] KVM: TDX: create/destroy VM structure [v18,025/121] KVM: TDX: initialize VM with TDX specific parameters [v18,026/121] KVM: TDX: Make pmu_intel.c ignore guest TD case [v18,027/121] KVM: TDX: Refuse to unplug the last cpu on the package [v18,028/121,MARKER] The start of TDX KVM patch series: TD vcpu creation/destruction [v18,029/121] KVM: TDX: create/free TDX vcpu structure [v18,030/121] KVM: TDX: Do TDX specific vcpu initialization [v18,031/121,MARKER] The start of TDX KVM patch series: KVM MMU GPA shared bits [v18,032/121] KVM: x86/mmu: introduce config for PRIVATE KVM MMU [v18,033/121] KVM: x86/mmu: Add address conversion functions for TDX shared bit of GPA [v18,034/121,MARKER] The start of TDX KVM patch series: KVM TDP refactoring for TDX [v18,035/121] KVM: Allow page-sized MMU caches to be initialized with custom 64-bit values [v18,036/121] KVM: x86/mmu: Replace hardcoded value 0 for the initial value for SPTE [v18,037/121] KVM: x86/mmu: Allow non-zero value for non-present SPTE and removed SPTE [v18,038/121] KVM: x86/mmu: Add Suppress VE bit to shadow_mmio_mask/shadow_present_mask [v18,039/121] KVM: x86/mmu: Track shadow MMIO value on a per-VM basis [v18,040/121] KVM: x86/mmu: Disallow fast page fault on private GPA [v18,041/121] KVM: x86/mmu: Allow per-VM override of the TDP max page level [v18,042/121] KVM: VMX: Introduce test mode related to EPT violation VE [v18,043/121,MARKER] The start of TDX KVM patch series: KVM TDP MMU hooks [v18,044/121] KVM: x86/mmu: Assume guest MMIOs are shared [v18,045/121] KVM: x86/tdp_mmu: Init role member of struct kvm_mmu_page at allocation [v18,046/121] KVM: x86/mmu: Add a new is_private member for union kvm_mmu_page_role [v18,047/121] KVM: x86/mmu: Add a private pointer to struct kvm_mmu_page [v18,048/121] KVM: x86/tdp_mmu: Don't zap private pages for unsupported cases [v18,049/121] KVM: x86/tdp_mmu: Apply mmu notifier callback to only shared GPA [v18,050/121] KVM: x86/tdp_mmu: Sprinkle __must_check [v18,051/121] KVM: x86/tdp_mmu: Support TDX private mapping for TDP MMU [v18,052/121,MARKER] The start of TDX KVM patch series: TDX EPT violation [v18,053/121] KVM: x86/mmu: TDX: Do not enable page track for TD guest [v18,054/121] KVM: VMX: Split out guts of EPT violation to common/exposed function [v18,055/121] KVM: VMX: Move setting of EPT MMU masks to common VT-x code [v18,056/121] KVM: TDX: Add accessors VMX VMCS helpers [v18,057/121] KVM: TDX: Add load_mmu_pgd method for TDX [v18,058/121] KVM: TDX: Retry seamcall when TDX_OPERAND_BUSY with operand SEPT [v18,059/121] KVM: TDX: Require TDP MMU and mmio caching for TDX [v18,060/121] KVM: TDX: TDP MMU TDX support [v18,061/121] KVM: TDX: MTRR: implement get_mt_mask() for TDX [v18,062/121,MARKER] The start of TDX KVM patch series: TD finalization [v18,063/121] KVM: x86/mmu: Introduce kvm_mmu_map_tdp_page() for use by TDX [v18,064/121] KVM: TDX: Create initial guest memory [v18,065/121] KVM: TDX: Finalize VM initialization [v18,066/121,MARKER] The start of TDX KVM patch series: TD vcpu enter/exit [v18,067/121] KVM: TDX: Implement TDX vcpu enter/exit path [v18,068/121] KVM: TDX: vcpu_run: save/restore host state(host kernel gs) [v18,069/121] KVM: TDX: restore host xsave state when exit from the guest TD [v18,070/121] KVM: x86: Allow to update cached values in kvm_user_return_msrs w/o wrmsr [v18,071/121] KVM: TDX: restore user ret MSRs [v18,072/121] KVM: TDX: Add TSX_CTRL msr into uret_msrs list [v18,073/121,MARKER] The start of TDX KVM patch series: TD vcpu exits/interrupts/hypercalls [v18,074/121] KVM: TDX: complete interrupts after tdexit [v18,075/121] KVM: TDX: restore debug store when TD exit [v18,076/121] KVM: TDX: handle vcpu migration over logical processor [v18,077/121] KVM: x86: Add a switch_db_regs flag to handle TDX's auto-switched behavior [v18,078/121] KVM: TDX: Add support for find pending IRQ in a protected local APIC [v18,079/121] KVM: x86: Assume timer IRQ was injected if APIC state is proteced [v18,080/121] KVM: TDX: remove use of struct vcpu_vmx from posted_interrupt.c [v18,081/121] KVM: TDX: Implement interrupt injection [v18,082/121] KVM: TDX: Implements vcpu request_immediate_exit [v18,083/121] KVM: TDX: Implement methods to inject NMI [v18,084/121] KVM: VMX: Modify NMI and INTR handlers to take intr_info as function argument [v18,085/121] KVM: VMX: Move NMI/exception handler to common helper [v18,086/121] KVM: x86: Split core of hypercall emulation to helper function [v18,087/121] KVM: TDX: Add a place holder to handle TDX VM exit [v18,088/121] KVM: TDX: Handle vmentry failure for INTEL TD guest [v18,089/121] KVM: TDX: handle EXIT_REASON_OTHER_SMI [v18,090/121] KVM: TDX: handle ept violation/misconfig exit [v18,091/121] KVM: TDX: handle EXCEPTION_NMI and EXTERNAL_INTERRUPT [v18,092/121] KVM: TDX: Handle EXIT_REASON_OTHER_SMI with MSMI [v18,093/121] KVM: TDX: Add a place holder for handler of TDX hypercalls (TDG.VP.VMCALL) [v18,094/121] KVM: TDX: handle KVM hypercall with TDG.VP.VMCALL [v18,095/121] KVM: TDX: Add KVM Exit for TDX TDG.VP.VMCALL [v18,096/121] KVM: TDX: Handle TDX PV CPUID hypercall [v18,097/121] KVM: TDX: Handle TDX PV HLT hypercall [v18,098/121] KVM: TDX: Handle TDX PV port io hypercall [v18,099/121] KVM: TDX: Handle TDX PV MMIO hypercall [v18,100/121] KVM: TDX: Implement callbacks for MSR operations for TDX [v18,101/121] KVM: TDX: Handle TDX PV rdmsr/wrmsr hypercall [v18,102/121] KVM: TDX: Handle MSR MTRRCap and MTRRDefType access [v18,103/121] KVM: TDX: Handle MSR IA32_FEAT_CTL MSR and IA32_MCG_EXT_CTL [v18,104/121] KVM: TDX: Handle TDG.VP.VMCALL<GetTdVmCallInfo> hypercall [v18,105/121] KVM: TDX: Silently discard SMI request [v18,106/121] KVM: TDX: Silently ignore INIT/SIPI [v18,107/121] KVM: TDX: Add methods to ignore accesses to CPU state [v18,108/121] KVM: TDX: Add methods to ignore guest instruction emulation [v18,109/121] KVM: TDX: Add a method to ignore dirty logging [v18,110/121] KVM: TDX: Add methods to ignore VMX preemption timer [v18,111/121] KVM: TDX: Add methods to ignore accesses to TSC [v18,112/121] KVM: TDX: Ignore setting up mce [v18,113/121] KVM: TDX: Add a method to ignore for TDX to ignore hypercall patch [v18,114/121] KVM: TDX: Add methods to ignore virtual apic related operation [v18,115/121] KVM: TDX: Inhibit APICv for TDX guest [v18,116/121] Documentation/virt/kvm: Document on Trust Domain Extensions(TDX) [v18,117/121] KVM: x86: design documentation on TDX support of x86 KVM TDP MMU [v18,118/121] KVM: TDX: Add hint TDX ioctl to release Secure-EPT [v18,119/121] RFC: KVM: x86: Add x86 callback to check cpuid [v18,120/121] RFC: KVM: x86, TDX: Add check for KVM_SET_CPUID2 [v18,121/121,MARKER] the end of (the first phase of) TDX KVM patch series

Message ID

62a4a92cf2c0d112de775129d0a592459fe778d1.1705965635.git.isaku.yamahata@intel.com (mailing list archive)

State

New, archived

Headers

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>,
	Kai Huang <kai.huang@intel.com>,
	chen.bo@intel.com,
	hang.yuan@intel.com,
	tina.zhang@intel.com
Subject: [PATCH v18 090/121] KVM: TDX: handle ept violation/misconfig exit
Date: Mon, 22 Jan 2024 15:54:06 -0800
Message-Id: 
 <62a4a92cf2c0d112de775129d0a592459fe778d1.1705965635.git.isaku.yamahata@intel.com>
In-Reply-To: <cover.1705965634.git.isaku.yamahata@intel.com>
References: <cover.1705965634.git.isaku.yamahata@intel.com>
Precedence: bulk
MIME-Version: 1.0
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Series

KVM TDX basic feature support | expand

Commit Message

Isaku Yamahata Jan. 22, 2024, 11:54 p.m. UTC

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

On EPT violation, call a common function, __vmx_handle_ept_violation() to
trigger x86 MMU code.  On EPT misconfiguration, exit to ring 3 with
KVM_EXIT_UNKNOWN.  because EPT misconfiguration can't happen as MMIO is
trigged by TDG.VP.VMCALL. No point to set a misconfiguration value for the
fast path.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>

---
v14 -> v15:
- use PFERR_GUEST_ENC_MASK to tell the fault is private
---
 arch/x86/kvm/vmx/common.h |  3 +++
 arch/x86/kvm/vmx/tdx.c    | 49 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
index 632af7a76d0a..027aa4175d2c 100644
--- a/arch/x86/kvm/vmx/common.h
+++ b/arch/x86/kvm/vmx/common.h
@@ -87,6 +87,9 @@  static inline int __vmx_handle_ept_violation(struct kvm_vcpu *vcpu, gpa_t gpa,
 	error_code |= (exit_qualification & EPT_VIOLATION_GVA_TRANSLATED) != 0 ?
 	       PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;
 
+	if (kvm_is_private_gpa(vcpu->kvm, gpa))
+		error_code |= PFERR_GUEST_ENC_MASK;
+
 	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
 }
 
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 96f43ce288c3..4418f04a1cf1 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1330,6 +1330,51 @@  void tdx_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode,
 	__vmx_deliver_posted_interrupt(vcpu, &tdx->pi_desc, vector);
 }
 
+static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu)
+{
+	unsigned long exit_qual;
+
+	if (kvm_is_private_gpa(vcpu->kvm, tdexit_gpa(vcpu))) {
+		/*
+		 * Always treat SEPT violations as write faults.  Ignore the
+		 * EXIT_QUALIFICATION reported by TDX-SEAM for SEPT violations.
+		 * TD private pages are always RWX in the SEPT tables,
+		 * i.e. they're always mapped writable.  Just as importantly,
+		 * treating SEPT violations as write faults is necessary to
+		 * avoid COW allocations, which will cause TDAUGPAGE failures
+		 * due to aliasing a single HPA to multiple GPAs.
+		 */
+#define TDX_SEPT_VIOLATION_EXIT_QUAL	EPT_VIOLATION_ACC_WRITE
+		exit_qual = TDX_SEPT_VIOLATION_EXIT_QUAL;
+	} else {
+		exit_qual = tdexit_exit_qual(vcpu);
+		if (exit_qual & EPT_VIOLATION_ACC_INSTR) {
+			pr_warn("kvm: TDX instr fetch to shared GPA = 0x%lx @ RIP = 0x%lx\n",
+				tdexit_gpa(vcpu), kvm_rip_read(vcpu));
+			vcpu->run->exit_reason = KVM_EXIT_EXCEPTION;
+			vcpu->run->ex.exception = PF_VECTOR;
+			vcpu->run->ex.error_code = exit_qual;
+			return 0;
+		}
+	}
+
+	trace_kvm_page_fault(vcpu, tdexit_gpa(vcpu), exit_qual);
+	return __vmx_handle_ept_violation(vcpu, tdexit_gpa(vcpu), exit_qual);
+}
+
+static int tdx_handle_ept_misconfig(struct kvm_vcpu *vcpu)
+{
+	WARN_ON_ONCE(1);
+
+	vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+	vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON;
+	vcpu->run->internal.ndata = 2;
+	vcpu->run->internal.data[0] = EXIT_REASON_EPT_MISCONFIG;
+	vcpu->run->internal.data[1] = vcpu->arch.last_vmentry_cpu;
+
+	return 0;
+}
+
 int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)
 {
 	union tdx_exit_reason exit_reason = to_tdx(vcpu)->exit_reason;
@@ -1390,6 +1435,10 @@  int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)
 	WARN_ON_ONCE(fastpath != EXIT_FASTPATH_NONE);
 
 	switch (exit_reason.basic) {
+	case EXIT_REASON_EPT_VIOLATION:
+		return tdx_handle_ept_violation(vcpu);
+	case EXIT_REASON_EPT_MISCONFIG:
+		return tdx_handle_ept_misconfig(vcpu);
 	case EXIT_REASON_OTHER_SMI:
 		/*
 		 * If reach here, it's not a Machine Check System Management

[v18,090/121] KVM: TDX: handle ept violation/misconfig exit

Commit Message

Patch