vm_event: rename MEM_ACCESS_EMULATE and MEM_ACCESS_EMULATE_NOWRITE

By naming, placing and bit shift convention, it could be taken as
implied that MEM_ACCESS_EMULATE and MEM_ACCESS_EMULATE_NOWRITE are
mem_access event specific flags (instead of being generally
applicable as vm_event flags). This patch renames them to
VM_EVENT_FLAG_EMULATE and VM_EVENT_FLAG_EMULATE_NOWRITE
respectively, and uses bit shifts following the rest of the
VM_EVENT_FLAG_ constants.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Acked-by: Tamas K Lengyel <tlengyel@novetta.com>

xen/arch/x86/mm/p2m.c

@@ -1418,7 +1418,7 @@ void p2m_mem_access_emulate_check(struct vcpu *v,
                                   const vm_event_response_t *rsp)
 {
     /* Mark vcpu for skipping one instruction upon rescheduling. */
-    if ( rsp->flags & MEM_ACCESS_EMULATE )
+    if ( rsp->flags & VM_EVENT_FLAG_EMULATE )
     {
         xenmem_access_t access;
         bool_t violation = 1;
@@ -1553,7 +1553,7 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned long gla,
     if ( v->arch.vm_event.emulate_flags )
     {
         hvm_mem_access_emulate_one((v->arch.vm_event.emulate_flags &
-                                    MEM_ACCESS_EMULATE_NOWRITE) != 0,
+                                    VM_EVENT_FLAG_EMULATE_NOWRITE) != 0,
                                    TRAP_invalid_op, HVM_DELIVER_NO_ERROR_CODE);
 
         v->arch.vm_event.emulate_flags = 0;

xen/include/public/vm_event.h

@@ -47,6 +47,19 @@
 #define VM_EVENT_FLAG_VCPU_PAUSED     (1 << 0)
 /* Flags to aid debugging mem_event */
 #define VM_EVENT_FLAG_FOREIGN         (1 << 1)
+/*
+ * The following flags can be set in response to a mem_access event.
+ *
+ * Emulate the fault-causing instruction (if set in the event response flags).
+ * This will allow the guest to continue execution without lifting the page
+ * access restrictions.
+ */
+#define VM_EVENT_FLAG_EMULATE         (1 << 2)
+/*
+ * Same as MEM_ACCESS_EMULATE, but with write operations or operations
+ * potentially having side effects (like memory mapped or port I/O) disabled.
+ */
+#define VM_EVENT_FLAG_EMULATE_NOWRITE (1 << 3)
 
 /*
  * Reasons for the vm event request
@@ -136,19 +149,6 @@ struct vm_event_regs_x86 {
 #define MEM_ACCESS_GLA_VALID            (1 << 3)
 #define MEM_ACCESS_FAULT_WITH_GLA       (1 << 4)
 #define MEM_ACCESS_FAULT_IN_GPT         (1 << 5)
-/*
- * The following flags can be set in the response.
- *
- * Emulate the fault-causing instruction (if set in the event response flags).
- * This will allow the guest to continue execution without lifting the page
- * access restrictions.
- */
-#define MEM_ACCESS_EMULATE              (1 << 6)
-/*
- * Same as MEM_ACCESS_EMULATE, but with write operations or operations
- * potentially having side effects (like memory mapped or port I/O) disabled.
- */
-#define MEM_ACCESS_EMULATE_NOWRITE      (1 << 7)
 
 struct vm_event_mem_access {
     uint64_t gfn;