2 files changed, 23 insertions, 11 deletions

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 8a3ceadb1366..8a16b083df2e 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -311,9 +311,13 @@ struct kvm_s390_interrupt {
 
 /* This structure represents a single trace buffer record. */
 struct kvm_trace_rec {
-        __u32 event:28;
-        __u32 extra_u32:3;
-        __u32 cycle_in:1;
+        /* variable rec_val
+         * is split into:
+         * bits 0 - 27  -> event id
+         * bits 28 -30  -> number of extra data args of size u32
+         * bits 31      -> binary indicator for if tsc is in record
+         */
+        __u32 rec_val;
         __u32 pid;
         __u32 vcpu_id;
         union {
@@ -327,6 +331,13 @@ struct kvm_trace_rec {
         } u;
 };
 
+#define TRACE_REC_EVENT_ID(val) \
+                (0x0fffffff & (val))
+#define TRACE_REC_NUM_DATA_ARGS(val) \
+                (0x70000000 & ((val) << 28))
+#define TRACE_REC_TCS(val) \
+                (0x80000000 & ((val) << 31))
+
 #define KVMIO 0xAE
 
 /*
diff --git a/virt/kvm/kvm_trace.c b/virt/kvm/kvm_trace.c
index 58141f31ea8f..9acb78b3cc9f 100644
--- a/virt/kvm/kvm_trace.c
+++ b/virt/kvm/kvm_trace.c
@@ -54,12 +54,13 @@ static void kvm_add_trace(void *probe_private, void *call_data,
         struct kvm_trace *kt = kvm_trace;
         struct kvm_trace_rec rec;
         struct kvm_vcpu *vcpu;
-        int    i, extra, size;
+        int    i, size;
+        u32    extra;
 
         if (unlikely(kt->trace_state != KVM_TRACE_STATE_RUNNING))
                 return;
 
-        rec.event       = va_arg(*args, u32);
+        rec.rec_val     = TRACE_REC_EVENT_ID(va_arg(*args, u32));
         vcpu            = va_arg(*args, struct kvm_vcpu *);
         rec.pid         = current->tgid;
         rec.vcpu_id     = vcpu->vcpu_id;
@@ -67,21 +68,21 @@ static void kvm_add_trace(void *probe_private, void *call_data,
         extra           = va_arg(*args, u32);
         WARN_ON(!(extra <= KVM_TRC_EXTRA_MAX));
         extra           = min_t(u32, extra, KVM_TRC_EXTRA_MAX);
-        rec.extra_u32   = extra;
 
-        rec.cycle_in    = p->cycle_in;
+        rec.rec_val |= TRACE_REC_TCS(p->cycle_in)
+                        | TRACE_REC_NUM_DATA_ARGS(extra);
 
-        if (rec.cycle_in) {
+        if (p->cycle_in) {
                 rec.u.cycle.cycle_u64 = get_cycles();
 
-                for (i = 0; i < rec.extra_u32; i++)
+                for (i = 0; i < extra; i++)
                         rec.u.cycle.extra_u32[i] = va_arg(*args, u32);
         } else {
-                for (i = 0; i < rec.extra_u32; i++)
+                for (i = 0; i < extra; i++)
                         rec.u.nocycle.extra_u32[i] = va_arg(*args, u32);
         }
 
-        size = calc_rec_size(rec.cycle_in, rec.extra_u32 * sizeof(u32));
+        size = calc_rec_size(p->cycle_in, extra * sizeof(u32));
         relay_write(kt->rchan, &rec, size);
 }