[v9,087/105] KVM: TDX: handle ept violation/misconfig exit

Message ID	07f45330c377c6fbd700e8538ed9f718bac07598.1664530908.git.isaku.yamahata@intel.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> 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> Subject: [PATCH v9 087/105] KVM: TDX: handle ept violation/misconfig exit Date: Fri, 30 Sep 2022 03:18:21 -0700 Message-Id: <07f45330c377c6fbd700e8538ed9f718bac07598.1664530908.git.isaku.yamahata@intel.com> In-Reply-To: <cover.1664530907.git.isaku.yamahata@intel.com> References: <cover.1664530907.git.isaku.yamahata@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	KVM TDX basic feature support \| expand [v9,000/105] KVM TDX basic feature support [v9,001/105] KVM: VMX: Move out vmx_x86_ops to 'main.c' to wrap VMX and TDX [v9,002/105] KVM: x86: Refactor KVM VMX module init/exit functions [v9,003/105] KVM: TDX: Add placeholders for TDX VM/vcpu structure [v9,004/105] x86/virt/tdx: Add a helper function to return system wide info about TDX module [v9,005/105] KVM: TDX: Initialize the TDX module when loading the KVM intel kernel module [v9,006/105] KVM: x86: Introduce vm_type to differentiate default VMs from confidential VMs [v9,007/105] KVM: TDX: Make TDX VM type supported [v9,008/105,MARKER] The start of TDX KVM patch series: TDX architectural definitions [v9,009/105] KVM: TDX: Define TDX architectural definitions [v9,010/105] KVM: TDX: Add TDX "architectural" error codes [v9,011/105] KVM: TDX: Add C wrapper functions for SEAMCALLs to the TDX module [v9,012/105] KVM: TDX: Add helper functions to print TDX SEAMCALL error [v9,013/105,MARKER] The start of TDX KVM patch series: TD VM creation/destruction [v9,014/105] KVM: TDX: Stub in tdx.h with structs, accessors, and VMCS helpers [v9,015/105] x86/cpu: Add helper functions to allocate/free TDX private host key id [v9,016/105] KVM: TDX: create/destroy VM structure [v9,017/105] KVM: TDX: Refuse to unplug the last cpu on the package [v9,018/105] KVM: TDX: x86: Add ioctl to get TDX systemwide parameters [v9,019/105] KVM: TDX: Add place holder for TDX VM specific mem_enc_op ioctl [v9,020/105] KVM: TDX: initialize VM with TDX specific parameters [v9,021/105] KVM: TDX: Make pmu_intel.c ignore guest TD case [v9,022/105,MARKER] The start of TDX KVM patch series: TD vcpu creation/destruction [v9,023/105] KVM: TDX: allocate/free TDX vcpu structure [v9,024/105] KVM: TDX: Do TDX specific vcpu initialization [v9,025/105] KVM: TDX: Use private memory for TDX [v9,026/105,MARKER] The start of TDX KVM patch series: KVM MMU GPA shared bits [v9,027/105] KVM: x86/mmu: introduce config for PRIVATE KVM MMU [v9,028/105] KVM: x86/mmu: Add address conversion functions for TDX shared bit of GPA [v9,029/105,MARKER] The start of TDX KVM patch series: KVM TDP refactoring for TDX [v9,030/105] KVM: x86/mmu: Replace hardcoded value 0 for the initial value for SPTE [v9,031/105] KVM: x86/mmu: Make sync_page not use hard-coded 0 as the initial SPTE value [v9,032/105] KVM: x86/mmu: Allow non-zero value for non-present SPTE and removed SPTE [v9,033/105] KVM: x86/mmu: Add Suppress VE bit to shadow_mmio_{value, mask} [v9,034/105] KVM: x86/mmu: Track shadow MMIO value on a per-VM basis [v9,035/105] KVM: TDX: Enable mmio spte caching always for TDX [v9,036/105] KVM: x86/mmu: Disallow fast page fault on private GPA [v9,037/105] KVM: x86/mmu: Allow per-VM override of the TDP max page level [v9,038/105] KVM: VMX: Introduce test mode related to EPT violation VE [v9,039/105,MARKER] The start of TDX KVM patch series: KVM TDP MMU hooks [v9,040/105] KVM: x86/tdp_mmu: refactor kvm_tdp_mmu_map() [v9,041/105] KVM: x86/tdp_mmu: Init role member of struct kvm_mmu_page at allocation [v9,042/105] KVM: x86/mmu: Require TDP MMU for TDX [v9,043/105] KVM: x86/mmu: Add a new is_private member for union kvm_mmu_page_role [v9,044/105] KVM: x86/mmu: Add a private pointer to struct kvm_mmu_page [v9,045/105] KVM: x86/tdp_mmu: Don't zap private pages for unsupported cases [v9,046/105] KVM: x86/tdp_mmu: Support TDX private mapping for TDP MMU [v9,047/105,MARKER] The start of TDX KVM patch series: TDX EPT violation [v9,048/105] KVM: x86/mmu: Disallow dirty logging for x86 TDX [v9,049/105] KVM: x86/tdp_mmu: Ignore unsupported mmu operation on private GFNs [v9,050/105] KVM: VMX: Split out guts of EPT violation to common/exposed function [v9,051/105] KVM: VMX: Move setting of EPT MMU masks to common VT-x code [v9,052/105] KVM: TDX: Add load_mmu_pgd method for TDX [v9,053/105] KVM: TDX: don't request KVM_REQ_APIC_PAGE_RELOAD [v9,054/105] KVM: x86/VMX: introduce vmx tlb_remote_flush and tlb_remote_flush_with_range [v9,055/105] KVM: TDX: TDP MMU TDX support [v9,056/105,MARKER] The start of TDX KVM patch series: KVM TDP MMU MapGPA [v9,057/105] KVM: Add functions to set GFN to private or shared [v9,058/105] KVM: x86/mmu: Introduce kvm_mmu_map_tdp_page() for use by TDX [v9,059/105] KVM: x86/tdp_mmu: implement MapGPA hypercall for TDX [v9,060/105,MARKER] The start of TDX KVM patch series: TD finalization [v9,061/105] KVM: TDX: Create initial guest memory [v9,062/105] KVM: TDX: Finalize VM initialization [v9,063/105,MARKER] The start of TDX KVM patch series: TD vcpu enter/exit [v9,064/105] KVM: TDX: Add helper assembly function to TDX vcpu [v9,065/105] KVM: TDX: Implement TDX vcpu enter/exit path [v9,066/105] KVM: TDX: vcpu_run: save/restore host state(host kernel gs) [v9,067/105] KVM: TDX: restore host xsave state when exit from the guest TD [v9,068/105] KVM: x86: Allow to update cached values in kvm_user_return_msrs w/o wrmsr [v9,069/105] KVM: TDX: restore user ret MSRs [v9,070/105,MARKER] The start of TDX KVM patch series: TD vcpu exits/interrupts/hypercalls [v9,071/105] KVM: TDX: complete interrupts after tdexit [v9,072/105] KVM: TDX: restore debug store when TD exit [v9,073/105] KVM: TDX: handle vcpu migration over logical processor [v9,074/105] KVM: x86: Add a switch_db_regs flag to handle TDX's auto-switched behavior [v9,075/105] KVM: TDX: Add support for find pending IRQ in a protected local APIC [v9,076/105] KVM: x86: Assume timer IRQ was injected if APIC state is proteced [v9,077/105] KVM: TDX: remove use of struct vcpu_vmx from posted_interrupt.c [v9,078/105] KVM: TDX: Implement interrupt injection [v9,079/105] KVM: TDX: Implements vcpu request_immediate_exit [v9,080/105] KVM: TDX: Implement methods to inject NMI [v9,081/105] KVM: VMX: Modify NMI and INTR handlers to take intr_info as function argument [v9,082/105] KVM: VMX: Move NMI/exception handler to common helper [v9,083/105] KVM: x86: Split core of hypercall emulation to helper function [v9,084/105] KVM: TDX: Add a place holder to handle TDX VM exit [v9,085/105] KVM: TDX: Retry seamcall when TDX_OPERAND_BUSY with operand SEPT [v9,086/105] KVM: TDX: handle EXIT_REASON_OTHER_SMI [v9,087/105] KVM: TDX: handle ept violation/misconfig exit [v9,088/105] KVM: TDX: handle EXCEPTION_NMI and EXTERNAL_INTERRUPT [v9,089/105] KVM: TDX: Add a place holder for handler of TDX hypercalls (TDG.VP.VMCALL) [v9,090/105] KVM: TDX: handle KVM hypercall with TDG.VP.VMCALL [v9,091/105] KVM: TDX: Handle TDX PV CPUID hypercall [v9,092/105] KVM: TDX: Handle TDX PV HLT hypercall [v9,093/105] KVM: TDX: Handle TDX PV port io hypercall [v9,094/105] KVM: TDX: Handle TDX PV MMIO hypercall [v9,095/105] KVM: TDX: Implement callbacks for MSR operations for TDX [v9,096/105] KVM: TDX: Handle TDX PV rdmsr/wrmsr hypercall [v9,097/105] KVM: TDX: Handle TDX PV report fatal error hypercall [v9,098/105] KVM: TDX: Handle TDX PV map_gpa hypercall [v9,099/105] KVM: TDX: Handle TDG.VP.VMCALL<GetTdVmCallInfo> hypercall [v9,100/105] KVM: TDX: Silently discard SMI request [v9,101/105] KVM: TDX: Silently ignore INIT/SIPI [v9,102/105] KVM: TDX: Add methods to ignore accesses to CPU state [v9,103/105] Documentation/virt/kvm: Document on Trust Domain Extensions(TDX) [v9,104/105] KVM: x86: design documentation on TDX support of x86 KVM TDP MMU [v9,105/105,MARKER] the end of (the first phase of) TDX KVM patch series

Message ID

07f45330c377c6fbd700e8538ed9f718bac07598.1664530908.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>
Subject: [PATCH v9 087/105] KVM: TDX: handle ept violation/misconfig exit
Date: Fri, 30 Sep 2022 03:18:21 -0700
Message-Id: 
 <07f45330c377c6fbd700e8538ed9f718bac07598.1664530908.git.isaku.yamahata@intel.com>
In-Reply-To: <cover.1664530907.git.isaku.yamahata@intel.com>
References: <cover.1664530907.git.isaku.yamahata@intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Series

KVM TDX basic feature support | expand

Commit Message

Isaku Yamahata Sept. 30, 2022, 10:18 a.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>
---
 arch/x86/kvm/vmx/tdx.c | 46 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index fbf7968bf718..def8eb3df75f 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1015,6 +1015,48 @@  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(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_UNKNOWN;
+	vcpu->run->hw.hardware_exit_reason = EXIT_REASON_EPT_MISCONFIG;
+
+	return 0;
+}
+
 int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)
 {
 	union tdx_exit_reason exit_reason = to_tdx(vcpu)->exit_reason;
@@ -1037,6 +1079,10 @@  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

[v9,087/105] KVM: TDX: handle ept violation/misconfig exit

Commit Message

Patch