[PATCH 3/5] VMX: sync VM-exit perf counters with known VM-exit reasons

[Jan Beulich <jbeulich@xxxxxxxx>]

This has gone out of sync over time. Introduce a simplistic mechanism to
hopefully keep things in sync going forward.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
I wasn't sure about the #ifdef: Using CONFIG_PERF_COUNTERS there would
seem slightly odd next to a construct which specifically abstracts away
this aspect.

--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -3869,7 +3869,10 @@ void vmx_vmexit_handler(struct cpu_user_
     else
         HVMTRACE_ND(VMEXIT, 0, 1/*cycles*/, exit_reason, regs->eip);
 
-    perfc_incra(vmexits, exit_reason);
+#ifdef VMX_PERF_EXIT_REASON_SIZE
+    BUILD_BUG_ON(VMX_PERF_EXIT_REASON_SIZE != EXIT_REASON_LAST + 1);
+#endif
+    perfc_incra(vmexits, (uint16_t)exit_reason);
 
     /* Handle the interrupt we missed before allowing any more in. */
     switch ( (uint16_t)exit_reason )
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -220,6 +220,8 @@ static inline void pi_clear_sn(struct pi
 #define EXIT_REASON_XSAVES              63
 #define EXIT_REASON_XRSTORS             64
 
+#define EXIT_REASON_LAST                EXIT_REASON_XRSTORS
+
 /*
  * Interruption-information format
  */
--- a/xen/include/asm-x86/perfc_defn.h
+++ b/xen/include/asm-x86/perfc_defn.h
@@ -6,7 +6,7 @@ PERFCOUNTER_ARRAY(exceptions,
 
 #ifdef CONFIG_HVM
 
-#define VMX_PERF_EXIT_REASON_SIZE 56
+#define VMX_PERF_EXIT_REASON_SIZE 65
 #define VMX_PERF_VECTOR_SIZE 0x20
 PERFCOUNTER_ARRAY(vmexits,              "vmexits", VMX_PERF_EXIT_REASON_SIZE)
 PERFCOUNTER_ARRAY(cause_vector,         "cause vector", VMX_PERF_VECTOR_SIZE)