1 files changed, 24 insertions, 6 deletions
diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
index 1567b67841..af2635fae9 100644
--- a/hw/9pfs/9p.h
+++ b/hw/9pfs/9p.h
@@ -100,8 +100,8 @@ typedef enum P9ProtoVersion {
     V9FS_PROTO_2000L = 0x02,
 } P9ProtoVersion;
 
-/**
- * @brief Minimum message size supported by this 9pfs server.
+/*
+ * Minimum message size supported by this 9pfs server.
  *
  * A client establishes a session by sending a Tversion request along with a
  * 'msize' parameter which suggests the server a maximum message size ever to be
@@ -231,7 +231,7 @@ static inline void v9fs_readdir_init(P9ProtoVersion proto_version, V9fsDir *dir)
     }
 }
 
-/**
+/*
  * Type for 9p fs drivers' (a.k.a. 9p backends) result of readdir requests,
  * which is a chained list of directory entries.
  */
@@ -289,8 +289,8 @@ typedef enum AffixType_t {
     AffixType_Suffix, /* A.k.a. postfix. */
 } AffixType_t;
 
-/**
- * @brief Unique affix of variable length.
+/*
+ * Unique affix of variable length.
  *
  * An affix is (currently) either a suffix or a prefix, which is either
  * going to be prepended (prefix) or appended (suffix) with some other
@@ -304,7 +304,7 @@ typedef struct VariLenAffix {
     AffixType_t type; /* Whether this affix is a suffix or a prefix. */
     uint64_t value; /* Actual numerical value of this affix. */
     /*
-     * Lenght of the affix, that is how many (of the lowest) bits of @c value
+     * Lenght of the affix, that is how many (of the lowest) bits of ``value``
      * must be used for appending/prepending this affix to its final resulting,
      * unique number.
      */
@@ -479,4 +479,22 @@ struct V9fsTransport {
     void        (*push_and_notify)(V9fsPDU *pdu);
 };
 
+#if defined(XATTR_SIZE_MAX)
+/* Linux */
+#define P9_XATTR_SIZE_MAX XATTR_SIZE_MAX
+#elif defined(CONFIG_DARWIN)
+/*
+ * Darwin doesn't seem to define a maximum xattr size in its user
+ * space header, so manually configure it across platforms as 64k.
+ *
+ * Having no limit at all can lead to QEMU crashing during large g_malloc()
+ * calls. Because QEMU does not currently support macOS guests, the below
+ * preliminary solution only works due to its being a reflection of the limit of
+ * Linux guests.
+ */
+#define P9_XATTR_SIZE_MAX 65536
+#else
+#error Missing definition for P9_XATTR_SIZE_MAX for this host system
+#endif
+
 #endif