KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 107 insertions, 0 deletions

diff --git a/include/trace/events/iscsi.h b/include/trace/events/iscsi.h
new file mode 100644
index 000000000..990fd154f
--- /dev/null
+++ b/include/trace/events/iscsi.h
@@ -0,0 +1,107 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM iscsi
+
+#if !defined(_TRACE_ISCSI_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_ISCSI_H
+
+#include <linux/tracepoint.h>
+
+/* max debug message length */
+#define ISCSI_MSG_MAX	256
+
+/*
+ * Declare tracepoint helper function.
+ */
+void iscsi_dbg_trace(void (*trace)(struct device *dev, struct va_format *),
+		     struct device *dev, const char *fmt, ...);
+
+/*
+ * Declare event class for iscsi debug messages.
+ */
+DECLARE_EVENT_CLASS(iscsi_log_msg,
+
+	TP_PROTO(struct device *dev, struct va_format *vaf),
+
+	TP_ARGS(dev, vaf),
+
+	TP_STRUCT__entry(
+		__string(dname, 	dev_name(dev)		)
+		__vstring(msg,		vaf->fmt, vaf->va)
+	),
+
+	TP_fast_assign(
+		__assign_str(dname);
+		__assign_vstr(msg, vaf->fmt, vaf->va);
+	),
+
+	TP_printk("%s: %s",__get_str(dname),  __get_str(msg)
+	)
+);
+
+/*
+ * Define event to capture iscsi connection debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_conn,
+	TP_PROTO(struct device *dev, struct va_format *vaf),
+
+	TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi session debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_session,
+	TP_PROTO(struct device *dev, struct va_format *vaf),
+
+	TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi error handling debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_eh,
+        TP_PROTO(struct device *dev, struct va_format *vaf),
+
+        TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi tcp debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_tcp,
+        TP_PROTO(struct device *dev, struct va_format *vaf),
+
+        TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi sw tcp debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_sw_tcp,
+	TP_PROTO(struct device *dev, struct va_format *vaf),
+
+	TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi transport session debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_trans_session,
+	TP_PROTO(struct device *dev, struct va_format *vaf),
+
+	TP_ARGS(dev, vaf)
+);
+
+/*
+ * Define event to capture iscsi transport connection debug messages.
+ */
+DEFINE_EVENT(iscsi_log_msg, iscsi_dbg_trans_conn,
+	TP_PROTO(struct device *dev, struct va_format *vaf),
+
+	TP_ARGS(dev, vaf)
+);
+
+#endif /* _TRACE_ISCSI_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>