KVM: SVM: Add tracepoint for skinit instruction

This patch adds a tracepoint for the event that the guest
executed the SKINIT instruction. This information is
important because SKINIT is an SVM extenstion not yet
implemented by nested SVM and we may need this information
for debugging hypervisors that do not yet run on nested SVM.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

3 files changed, 32 insertions, 1 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ba18fb7d3657..8b9f6fbba48c 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1987,6 +1987,14 @@ static int invlpga_interception(struct vcpu_svm *svm)
         return 1;
 }
 
+static int skinit_interception(struct vcpu_svm *svm)
+{
+        trace_kvm_skinit(svm->vmcb->save.rip, svm->vcpu.arch.regs[VCPU_REGS_RAX]);
+
+        kvm_queue_exception(&svm->vcpu, UD_VECTOR);
+        return 1;
+}
+
 static int invalid_op_interception(struct vcpu_svm *svm)
 {
         kvm_queue_exception(&svm->vcpu, UD_VECTOR);
@@ -2350,7 +2358,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm) = {
         [SVM_EXIT_VMSAVE]                       = vmsave_interception,
         [SVM_EXIT_STGI]                         = stgi_interception,
         [SVM_EXIT_CLGI]                         = clgi_interception,
-        [SVM_EXIT_SKINIT]                       = invalid_op_interception,
+        [SVM_EXIT_SKINIT]                       = skinit_interception,
         [SVM_EXIT_WBINVD]                       = emulate_on_interception,
         [SVM_EXIT_MONITOR]                      = invalid_op_interception,
         [SVM_EXIT_MWAIT]                        = invalid_op_interception,
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index 7e1f08e959bc..816e0449db0b 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -492,6 +492,28 @@ TRACE_EVENT(kvm_invlpga,
         TP_printk("rip: 0x%016llx asid: %d address: 0x%016llx\n",
                   __entry->rip, __entry->asid, __entry->address)
 );
+
+/*
+ * Tracepoint for nested #vmexit because of interrupt pending
+ */
+TRACE_EVENT(kvm_skinit,
+            TP_PROTO(__u64 rip, __u32 slb),
+            TP_ARGS(rip, slb),
+
+        TP_STRUCT__entry(
+                __field(        __u64,  rip     )
+                __field(        __u32,  slb     )
+        ),
+
+        TP_fast_assign(
+                __entry->rip            =       rip;
+                __entry->slb            =       slb;
+        ),
+
+        TP_printk("rip: 0x%016llx slb: 0x%08x\n",
+                  __entry->rip, __entry->slb)
+);
+
 #endif /* _TRACE_KVM_H */
 
 /* This part must be outside protection */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 86596fc7941c..098e7f886306 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4989,3 +4989,4 @@ 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_invlpga);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_skinit);