[PATCH 2/2] KVM: nVMX: trace nested vm entry

From: Maxim Levitsky
Date: Thu Jan 21 2021 - 12:16:27 EST


This is very helpful to debug nested VMX issues.

Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
arch/x86/kvm/trace.h | 30 ++++++++++++++++++++++++++++++
arch/x86/kvm/vmx/nested.c | 5 +++++
arch/x86/kvm/x86.c | 3 ++-
3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index 2de30c20bc264..ec75efdac3560 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -554,6 +554,36 @@ TRACE_EVENT(kvm_nested_vmrun,
__entry->npt ? "on" : "off")
);

+
+/*
+ * Tracepoint for nested VMLAUNCH/VMRESUME
+ */
+TRACE_EVENT(kvm_nested_vmenter,
+ TP_PROTO(__u64 rip, __u64 vmcs, __u64 nested_rip,
+ __u32 entry_intr_info),
+ TP_ARGS(rip, vmcs, nested_rip, entry_intr_info),
+
+ TP_STRUCT__entry(
+ __field( __u64, rip )
+ __field( __u64, vmcs )
+ __field( __u64, nested_rip )
+ __field( __u32, entry_intr_info )
+ ),
+
+ TP_fast_assign(
+ __entry->rip = rip;
+ __entry->vmcs = vmcs;
+ __entry->nested_rip = nested_rip;
+ __entry->entry_intr_info = entry_intr_info;
+ ),
+
+ TP_printk("rip: 0x%016llx vmcs: 0x%016llx nrip: 0x%016llx "
+ "entry_intr_info: 0x%08x",
+ __entry->rip, __entry->vmcs, __entry->nested_rip,
+ __entry->entry_intr_info)
+);
+
+
TRACE_EVENT(kvm_nested_intercepts,
TP_PROTO(__u16 cr_read, __u16 cr_write, __u32 exceptions,
__u32 intercept1, __u32 intercept2, __u32 intercept3),
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 0fbb46990dfce..20b0954f31bda 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3327,6 +3327,11 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
vmx->nested.vmcs01_guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);

+ trace_kvm_nested_vmenter(kvm_rip_read(vcpu),
+ vmx->nested.current_vmptr,
+ vmcs12->guest_rip,
+ vmcs12->vm_entry_intr_info_field);
+
/*
* Overwrite vmcs01.GUEST_CR3 with L1's CR3 if EPT is disabled *and*
* nested early checks are disabled. In the event of a "late" VM-Fail,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a480804ae27a3..757f4f88072af 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11562,11 +11562,12 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_msr);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_cr);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmenter);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmenter_failed);
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_nested_intr_vmexit);
-EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmenter_failed);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_invlpga);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_skinit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intercepts);
--
2.26.2