stat64: Add stat64_set() operation

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>

include/qemu/stats64.h

@@ -40,6 +40,11 @@ static inline uint64_t stat64_get(const Stat64 *s)
     return qatomic_read__nocheck(&s->value);
 }
 
+static inline void stat64_set(Stat64 *s, uint64_t value)
+{
+    qatomic_set__nocheck(&s->value, value);
+}
+
 static inline void stat64_add(Stat64 *s, uint64_t value)
 {
     qatomic_add(&s->value, value);
@@ -62,6 +67,7 @@ static inline void stat64_max(Stat64 *s, uint64_t value)
 }
 #else
 uint64_t stat64_get(const Stat64 *s);
+void stat64_set(Stat64 *s, uint64_t value);
 bool stat64_min_slow(Stat64 *s, uint64_t value);
 bool stat64_max_slow(Stat64 *s, uint64_t value);
 bool stat64_add32_carry(Stat64 *s, uint32_t low, uint32_t high);

util/stats64.c

@@ -57,6 +57,17 @@ uint64_t stat64_get(const Stat64 *s)
     return ((uint64_t)high << 32) | low;
 }
 
+void stat64_set(Stat64 *s, uint64_t val)
+{
+    while (!stat64_wrtrylock(s)) {
+        cpu_relax();
+    }
+
+    qatomic_set(&s->high, val >> 32);
+    qatomic_set(&s->low, val);
+    stat64_wrunlock(s);
+}
+
 bool stat64_add32_carry(Stat64 *s, uint32_t low, uint32_t high)
 {
     uint32_t old;