diff --git a/tools/xentrace/formats b/tools/xentrace/formats
index deac4d8..9e7056c 100644
--- a/tools/xentrace/formats
+++ b/tools/xentrace/formats
@@ -132,6 +132,12 @@
 0x00082020  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  INTR_WINDOW [ value = 0x%(1)08x ]
 0x00082021  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  NPF         [ gpa = 0x%(2)08x%(1)08x mfn = 0x%(4)08x%(3)08x qual = 0x%(5)04x p2mt = 0x%(6)04x ]
 0x00082023  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  TRAP        [ vector = 0x%(1)02x ]
+0x00082024  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  TRAP_DEBUG  [ exit_qualification = 0x%(1)08x ]
+0x00082025  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  VLAPIC
+0x00082028  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  VMPORT_HANDLED   [ cmd = %(1)d eax = 0x%(2)08x ebx = 0x%(3)08x ecx = 0x%(4)08x edx = 0x%(5)08x esi = 0x%(6)08x edi = 0x%(7)08x ]
+0x00082029  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  VMPORT_IGNORED   [ port = %(1)d eax = 0x%(2)08x ]
+0x0008202a  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  VMPORT_QEMU      [ eax = 0x%(1)08x ebx = 0x%(2)08x ecx = 0x%(3)08x edx = 0x%(4)08x esi = 0x%(5)08x edi = 0x%(6)08x ]
+0x0008202b  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  VMPORT_SEND      [ cmd = 0x%(1)08x ebx = 0x%(2)08x ecx = 0x%(3)08x edx = 0x%(4)08x esi = 0x%(5)08x edi = 0x%(6)08x ]
 
 0x0010f001  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  page_grant_map      [ domid = %(1)d ]
 0x0010f002  CPU%(cpu)d  %(tsc)d (+%(reltsc)8d)  page_grant_unmap    [ domid = %(1)d ]
diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c
index a5d124e..c64fda8 100644
--- a/xen/arch/x86/hvm/ioreq.c
+++ b/xen/arch/x86/hvm/ioreq.c
@@ -262,6 +262,9 @@ bool handle_hvm_io_completion(struct vcpu *v)
                 regs->edx = vr->edx;
                 regs->esi = vr->esi;
                 regs->edi = vr->edi;
+                HVMTRACE_ND(VMPORT_QEMU, 0, 1/*cycles*/, 6,
+                            vio->io_req.data, regs->ebx, regs->ecx,
+                            regs->edx, regs->esi, regs->edi, 0);
             }
         }
         return handle_pio(vio->io_req.addr, vio->io_req.size,
diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index ca3bbfc..60c030a 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -1052,7 +1052,7 @@ void svm_vmenter_helper(const struct cpu_user_regs *regs)
     if ( unlikely(tb_init_done) )
         HVMTRACE_ND(VMENTRY,
                     nestedhvm_vcpu_in_guestmode(curr) ? TRC_HVM_NESTEDFLAG : 0,
-                    1/*cycles*/, 0, 0, 0, 0, 0, 0, 0);
+                    1/*cycles*/, 0, 0, 0, 0, 0, 0, 0, 0);
 
     svm_sync_vmcb(curr, vmcb_needs_vmsave);
 
@@ -2531,11 +2531,11 @@ void svm_vmexit_handler(struct cpu_user_regs *regs)
     if ( hvm_long_mode_active(v) )
         HVMTRACE_ND(VMEXIT64, vcpu_guestmode ? TRC_HVM_NESTEDFLAG : 0,
                     1/*cycles*/, 3, exit_reason,
-                    regs->eip, regs->rip >> 32, 0, 0, 0);
+                    regs->eip, regs->rip >> 32, 0, 0, 0, 0);
     else
         HVMTRACE_ND(VMEXIT, vcpu_guestmode ? TRC_HVM_NESTEDFLAG : 0,
                     1/*cycles*/, 2, exit_reason,
-                    regs->eip, 0, 0, 0, 0);
+                    regs->eip, 0, 0, 0, 0, 0);
 
     if ( vcpu_guestmode )
     {
diff --git a/xen/arch/x86/hvm/vmware/vmport.c b/xen/arch/x86/hvm/vmware/vmport.c
index 3c2e7d5..0467aff 100644
--- a/xen/arch/x86/hvm/vmware/vmport.c
+++ b/xen/arch/x86/hvm/vmware/vmport.c
@@ -17,6 +17,7 @@
 #include <asm/mc146818rtc.h>
 #include <asm/hvm/hvm.h>
 #include <asm/hvm/support.h>
+#include <asm/hvm/trace.h>
 
 #include "backdoor_def.h"
 
@@ -62,6 +63,7 @@ static int vmport_ioport(int dir, uint32_t port, uint32_t bytes, uint32_t *val)
     if ( port == BDOOR_PORT && regs->eax == BDOOR_MAGIC )
     {
         uint32_t new_eax = ~0u;
+        uint16_t cmd = regs->ecx;
         uint64_t value;
         struct vcpu *curr = current;
         struct domain *currd = curr->domain;
@@ -72,7 +74,7 @@ static int vmport_ioport(int dir, uint32_t port, uint32_t bytes, uint32_t *val)
          * leaving the high 32-bits unchanged, unlike what one would
          * expect to happen.
          */
-        switch ( regs->ecx & 0xffff )
+        switch ( cmd )
         {
         case BDOOR_CMD_GETMHZ:
             new_eax = currd->arch.tsc_khz / 1000;
@@ -147,14 +149,22 @@ static int vmport_ioport(int dir, uint32_t port, uint32_t bytes, uint32_t *val)
             break;
 
         default:
+            HVMTRACE_6D(VMPORT_SEND, cmd, regs->ebx, regs->ecx,
+                        regs->edx, regs->esi, regs->edi);
             /* Let backing DM handle */
             return X86EMUL_UNHANDLEABLE;
         }
+        HVMTRACE_7D(VMPORT_HANDLED, cmd, new_eax, regs->ebx, regs->ecx,
+                    regs->edx, regs->esi, regs->edi);
         if ( dir == IOREQ_READ )
             *val = new_eax;
     }
-    else if ( dir == IOREQ_READ )
-        *val = ~0u;
+    else
+    {
+        HVMTRACE_2D(VMPORT_IGNORED, port, regs->eax);
+        if ( dir == IOREQ_READ )
+            *val = ~0u;
+    }
 
     return X86EMUL_OKAY;
 }
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index a0d58ff..8cba2a3 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -3683,10 +3683,10 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
 
     if ( hvm_long_mode_active(v) )
         HVMTRACE_ND(VMEXIT64, 0, 1/*cycles*/, 3, exit_reason,
-                    regs->eip, regs->rip >> 32, 0, 0, 0);
+                    regs->eip, regs->rip >> 32, 0, 0, 0, 0);
     else
         HVMTRACE_ND(VMEXIT, 0, 1/*cycles*/, 2, exit_reason,
-                    regs->eip, 0, 0, 0, 0);
+                    regs->eip, 0, 0, 0, 0, 0);
 
     perfc_incra(vmexits, exit_reason);
 
@@ -4463,7 +4463,7 @@ bool vmx_vmenter_helper(const struct cpu_user_regs *regs)
     if ( unlikely(curr->arch.hvm.vmx.lbr_flags & LBR_FIXUP_MASK) )
         lbr_fixup();
 
-    HVMTRACE_ND(VMENTRY, 0, 1/*cycles*/, 0, 0, 0, 0, 0, 0, 0);
+    HVMTRACE_ND(VMENTRY, 0, 1/*cycles*/, 0, 0, 0, 0, 0, 0, 0, 0);
 
     __vmwrite(GUEST_RIP,    regs->rip);
     __vmwrite(GUEST_RSP,    regs->rsp);
diff --git a/xen/include/asm-x86/hvm/trace.h b/xen/include/asm-x86/hvm/trace.h
index 5cd459b..9d7f04e 100644
--- a/xen/include/asm-x86/hvm/trace.h
+++ b/xen/include/asm-x86/hvm/trace.h
@@ -56,6 +56,10 @@
 #define DO_TRC_HVM_TRAP             DEFAULT_HVM_MISC
 #define DO_TRC_HVM_TRAP_DEBUG       DEFAULT_HVM_MISC
 #define DO_TRC_HVM_VLAPIC           DEFAULT_HVM_MISC
+#define DO_TRC_HVM_VMPORT_HANDLED   DEFAULT_HVM_IO
+#define DO_TRC_HVM_VMPORT_IGNORED   DEFAULT_HVM_IO
+#define DO_TRC_HVM_VMPORT_QEMU      DEFAULT_HVM_IO
+#define DO_TRC_HVM_VMPORT_SEND      DEFAULT_HVM_IO
 
 
 #define TRC_PAR_LONG(par) ((par)&0xFFFFFFFF),((par)>>32)
@@ -67,38 +71,34 @@
 #define TRACE_2_LONG_4D(_e, d1, d2, d3, d4, ...) \
     TRACE_6D(_e, d1, d2, d3, d4)
 
-#define HVMTRACE_ND(evt, modifier, cycles, count, d1, d2, d3, d4, d5, d6) \
-    do {                                                                  \
-        if ( unlikely(tb_init_done) && DO_TRC_HVM_ ## evt )               \
-        {                                                                 \
-            struct {                                                      \
-                u32 d[6];                                                 \
-            } _d;                                                         \
-            _d.d[0]=(d1);                                                 \
-            _d.d[1]=(d2);                                                 \
-            _d.d[2]=(d3);                                                 \
-            _d.d[3]=(d4);                                                 \
-            _d.d[4]=(d5);                                                 \
-            _d.d[5]=(d6);                                                 \
-            __trace_var(TRC_HVM_ ## evt | (modifier), cycles,             \
-                        sizeof(*_d.d) * count, &_d);                      \
-        }                                                                 \
+#define HVMTRACE_ND(evt, modifier, cycles, count, d1, d2, d3, d4, d5, d6, d7) \
+    do {                                                                      \
+        if ( unlikely(tb_init_done) && DO_TRC_HVM_ ## evt )                   \
+        {                                                                     \
+            struct {                                                          \
+                u32 d[7];                                                     \
+            } _d = { { d1, d2, d3, d4, d5, d6, d7 } };                        \
+            __trace_var(TRC_HVM_ ## evt | (modifier), cycles,                 \
+                        sizeof(*_d.d) * count, &_d);                          \
+        }                                                                     \
     } while(0)
 
-#define HVMTRACE_6D(evt, d1, d2, d3, d4, d5, d6)    \
-    HVMTRACE_ND(evt, 0, 0, 6, d1, d2, d3, d4, d5, d6)
-#define HVMTRACE_5D(evt, d1, d2, d3, d4, d5)        \
-    HVMTRACE_ND(evt, 0, 0, 5, d1, d2, d3, d4, d5,  0)
-#define HVMTRACE_4D(evt, d1, d2, d3, d4)            \
-    HVMTRACE_ND(evt, 0, 0, 4, d1, d2, d3, d4,  0,  0)
-#define HVMTRACE_3D(evt, d1, d2, d3)                \
-    HVMTRACE_ND(evt, 0, 0, 3, d1, d2, d3,  0,  0,  0)
-#define HVMTRACE_2D(evt, d1, d2)                    \
-    HVMTRACE_ND(evt, 0, 0, 2, d1, d2,  0,  0,  0,  0)
-#define HVMTRACE_1D(evt, d1)                        \
-    HVMTRACE_ND(evt, 0, 0, 1, d1,  0,  0,  0,  0,  0)
-#define HVMTRACE_0D(evt)                            \
-    HVMTRACE_ND(evt, 0, 0, 0,  0,  0,  0,  0,  0,  0)
+#define HVMTRACE_7D(evt, d1, d2, d3, d4, d5, d6, d7) \
+    HVMTRACE_ND(evt, 0, 0, 7, d1, d2, d3, d4, d5, d6, d7)
+#define HVMTRACE_6D(evt, d1, d2, d3, d4, d5, d6)     \
+    HVMTRACE_ND(evt, 0, 0, 6, d1, d2, d3, d4, d5, d6, 0)
+#define HVMTRACE_5D(evt, d1, d2, d3, d4, d5)         \
+    HVMTRACE_ND(evt, 0, 0, 5, d1, d2, d3, d4, d5,  0, 0)
+#define HVMTRACE_4D(evt, d1, d2, d3, d4)             \
+    HVMTRACE_ND(evt, 0, 0, 4, d1, d2, d3, d4,  0,  0, 0)
+#define HVMTRACE_3D(evt, d1, d2, d3)                 \
+    HVMTRACE_ND(evt, 0, 0, 3, d1, d2, d3,  0,  0,  0, 0)
+#define HVMTRACE_2D(evt, d1, d2)                     \
+    HVMTRACE_ND(evt, 0, 0, 2, d1, d2,  0,  0,  0,  0, 0)
+#define HVMTRACE_1D(evt, d1)                         \
+    HVMTRACE_ND(evt, 0, 0, 1, d1,  0,  0,  0,  0,  0, 0)
+#define HVMTRACE_0D(evt)                             \
+    HVMTRACE_ND(evt, 0, 0, 0,  0,  0,  0,  0,  0,  0, 0)
 
 #define HVMTRACE_LONG_1D(evt, d1)                  \
                    HVMTRACE_2D(evt ## 64, (d1) & 0xFFFFFFFF, (d1) >> 32)
diff --git a/xen/include/public/trace.h b/xen/include/public/trace.h
index d5fa4ae..6b93f62 100644
--- a/xen/include/public/trace.h
+++ b/xen/include/public/trace.h
@@ -237,6 +237,10 @@
 #define TRC_HVM_VLAPIC           (TRC_HVM_HANDLER + 0x25)
 #define TRC_HVM_XCR_READ64      (TRC_HVM_HANDLER + TRC_64_FLAG + 0x26)
 #define TRC_HVM_XCR_WRITE64     (TRC_HVM_HANDLER + TRC_64_FLAG + 0x27)
+#define TRC_HVM_VMPORT_HANDLED  (TRC_HVM_HANDLER + 0x28)
+#define TRC_HVM_VMPORT_IGNORED  (TRC_HVM_HANDLER + 0x29)
+#define TRC_HVM_VMPORT_QEMU     (TRC_HVM_HANDLER + 0x2a)
+#define TRC_HVM_VMPORT_SEND     (TRC_HVM_HANDLER + 0x2b)
 
 #define TRC_HVM_IOPORT_WRITE    (TRC_HVM_HANDLER + 0x216)
 #define TRC_HVM_IOMEM_WRITE     (TRC_HVM_HANDLER + 0x217)
