Re: [RFC PATCH v2 67/69] KVM: TDX: add trace point for TDVMCALL and SEPT operation

Paolo Bonzini <pbonzini@xxxxxxxxxx> · Tue, 6 Jul 2021 16:23:04 +0200

On 03/07/21 00:05, isaku.yamahata@xxxxxxxxx wrote:
From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

Signed-off-by: Yuan Yao <yuan.yao@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
  arch/x86/kvm/trace.h        | 58 +++++++++++++++++++++++++++++++++++++
  arch/x86/kvm/vmx/tdx.c      | 16 ++++++++++
  arch/x86/kvm/vmx/tdx_arch.h |  9 ++++++
  arch/x86/kvm/x86.c          |  2 ++
  4 files changed, 85 insertions(+)

diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index c3398d0de9a7..58631124f08d 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -739,6 +739,64 @@ TRACE_EVENT(kvm_tdx_seamcall_exit,
  		  __entry->r9, __entry->r10, __entry->r11)
  );
  
+/*
+ * Tracepoint for TDVMCALL from a TDX guest
+ */
+TRACE_EVENT(kvm_tdvmcall,
+	TP_PROTO(struct kvm_vcpu *vcpu, __u32 exit_reason,
+		 __u64 p1, __u64 p2, __u64 p3, __u64 p4),
+	TP_ARGS(vcpu, exit_reason, p1, p2, p3, p4),
+
+	TP_STRUCT__entry(
+		__field(	__u64,		rip		)
+		__field(	__u32,		exit_reason	)
+		__field(	__u64,		p1		)
+		__field(	__u64,		p2		)
+		__field(	__u64,		p3		)
+		__field(	__u64,		p4		)
+	),
+
+	TP_fast_assign(
+		__entry->rip			= kvm_rip_read(vcpu);
+		__entry->exit_reason		= exit_reason;
+		__entry->p1			= p1;
+		__entry->p2			= p2;
+		__entry->p3			= p3;
+		__entry->p4			= p4;
+	),
+
+	TP_printk("rip: %llx reason: %s p1: %llx p2: %llx p3: %llx p4: %llx",
+		  __entry->rip,
+		  __print_symbolic(__entry->exit_reason,
+				   TDG_VP_VMCALL_EXIT_REASONS),
+		  __entry->p1, __entry->p2, __entry->p3, __entry->p4)
+);
+
+/*
+ * Tracepoint for SEPT related SEAMCALLs.
+ */
+TRACE_EVENT(kvm_sept_seamcall,
+	TP_PROTO(__u64 op, __u64 gpa, __u64 hpa, int level),
+	TP_ARGS(op, gpa, hpa, level),
+
+	TP_STRUCT__entry(
+		__field(	__u64,		op	)
+		__field(	__u64,		gpa	)
+		__field(	__u64,		hpa	)
+		__field(	int,		level	)
+	),
+
+	TP_fast_assign(
+		__entry->op			= op;
+		__entry->gpa			= gpa;
+		__entry->hpa			= hpa;
+		__entry->level			= level;
+	),
+
+	TP_printk("op: %llu gpa: 0x%llx hpa: 0x%llx level: %u",
+		  __entry->op, __entry->gpa, __entry->hpa, __entry->level)
+);
+
  /*
   * Tracepoint for nested #vmexit because of interrupt pending
   */
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 1aed4286ce0c..63130fb5a003 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -934,6 +934,10 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu)
  
  	exit_reason = tdvmcall_exit_reason(vcpu);
  
+	trace_kvm_tdvmcall(vcpu, exit_reason,
+			   tdvmcall_p1_read(vcpu), tdvmcall_p2_read(vcpu),
+			   tdvmcall_p3_read(vcpu), tdvmcall_p4_read(vcpu));
+
  	switch (exit_reason) {
  	case EXIT_REASON_CPUID:
  		return tdx_emulate_cpuid(vcpu);
@@ -1011,11 +1015,15 @@ static void tdx_sept_set_private_spte(struct kvm_vcpu *vcpu, gfn_t gfn,
  
  	/* Build-time faults are induced and handled via TDH_MEM_PAGE_ADD. */
  	if (is_td_finalized(kvm_tdx)) {
+		trace_kvm_sept_seamcall(SEAMCALL_TDH_MEM_PAGE_AUG, gpa, hpa, level);
+
  		err = tdh_mem_page_aug(kvm_tdx->tdr.pa, gpa, hpa, &ex_ret);
  		SEPT_ERR(err, &ex_ret, TDH_MEM_PAGE_AUG, vcpu->kvm);
  		return;
  	}
  
+	trace_kvm_sept_seamcall(SEAMCALL_TDH_MEM_PAGE_ADD, gpa, hpa, level);
+
  	source_pa = kvm_tdx->source_pa & ~KVM_TDX_MEASURE_MEMORY_REGION;
  
  	err = tdh_mem_page_add(kvm_tdx->tdr.pa,  gpa, hpa, source_pa, &ex_ret);
@@ -1039,6 +1047,8 @@ static void tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn, int level,
  		return;
  
  	if (is_hkid_assigned(kvm_tdx)) {
+		trace_kvm_sept_seamcall(SEAMCALL_TDH_MEM_PAGE_REMOVE, gpa, hpa, level);
+
  		err = tdh_mem_page_remove(kvm_tdx->tdr.pa, gpa, level, &ex_ret);
  		if (SEPT_ERR(err, &ex_ret, TDH_MEM_PAGE_REMOVE, kvm))
  			return;
@@ -1063,6 +1073,8 @@ static int tdx_sept_link_private_sp(struct kvm_vcpu *vcpu, gfn_t gfn,
  	struct tdx_ex_ret ex_ret;
  	u64 err;
  
+	trace_kvm_sept_seamcall(SEAMCALL_TDH_MEM_SEPT_ADD, gpa, hpa, level);
+
  	err = tdh_mem_spet_add(kvm_tdx->tdr.pa, gpa, level, hpa, &ex_ret);
  	if (SEPT_ERR(err, &ex_ret, TDH_MEM_SEPT_ADD, vcpu->kvm))
  		return -EIO;
@@ -1077,6 +1089,8 @@ static void tdx_sept_zap_private_spte(struct kvm *kvm, gfn_t gfn, int level)
  	struct tdx_ex_ret ex_ret;
  	u64 err;
  
+	trace_kvm_sept_seamcall(SEAMCALL_TDH_MEM_RANGE_BLOCK, gpa, -1ull, level);
+
  	err = tdh_mem_range_block(kvm_tdx->tdr.pa, gpa, level, &ex_ret);
  	SEPT_ERR(err, &ex_ret, TDH_MEM_RANGE_BLOCK, kvm);
  }
@@ -1088,6 +1102,8 @@ static void tdx_sept_unzap_private_spte(struct kvm *kvm, gfn_t gfn, int level)
  	struct tdx_ex_ret ex_ret;
  	u64 err;
  
+	trace_kvm_sept_seamcall(SEAMCALL_TDH_MEM_RANGE_UNBLOCK, gpa, -1ull, level);
+
  	err = tdh_mem_range_unblock(kvm_tdx->tdr.pa, gpa, level, &ex_ret);
  	SEPT_ERR(err, &ex_ret, TDH_MEM_RANGE_UNBLOCK, kvm);
  }
diff --git a/arch/x86/kvm/vmx/tdx_arch.h b/arch/x86/kvm/vmx/tdx_arch.h
index 7258825b1e02..414b933a3b03 100644
--- a/arch/x86/kvm/vmx/tdx_arch.h
+++ b/arch/x86/kvm/vmx/tdx_arch.h
@@ -104,6 +104,15 @@
  #define TDG_VP_VMCALL_REPORT_FATAL_ERROR		0x10003
  #define TDG_VP_VMCALL_SETUP_EVENT_NOTIFY_INTERRUPT	0x10004
  
+#define TDG_VP_VMCALL_EXIT_REASONS				\
+	{ TDG_VP_VMCALL_GET_TD_VM_CALL_INFO,			\
+			"GET_TD_VM_CALL_INFO" },		\
+	{ TDG_VP_VMCALL_MAP_GPA,	"MAP_GPA" },		\
+	{ TDG_VP_VMCALL_GET_QUOTE,	"GET_QUOTE" },		\
+	{ TDG_VP_VMCALL_SETUP_EVENT_NOTIFY_INTERRUPT,		\
+			"SETUP_EVENT_NOTIFY_INTERRUPT" },	\
+	VMX_EXIT_REASONS
+
  /* TDX control structure (TDR/TDCS/TDVPS) field access codes */
  #define TDX_CLASS_SHIFT		56
  #define TDX_FIELD_MASK		GENMASK_ULL(31, 0)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ba69abcc663a..ad619c1b2a88 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12104,6 +12104,8 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_cr);
  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmrun);
  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmexit);
  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmexit_inject);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_tdvmcall);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_sept_seamcall);
  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intr_vmexit);
  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmenter_failed);
  EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_invlpga);


Please split this in two parts for each tracepoint, and squash it in the 
earlier patches that introduced handle_tdvmcall and tdx_sept_*.

Paolo







