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, 69 insertions, 0 deletions

diff --git a/include/trace/events/vb2.h b/include/trace/events/vb2.h
new file mode 100644
index 000000000..a40146dea
--- /dev/null
+++ b/include/trace/events/vb2.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM vb2
+
+#if !defined(_TRACE_VB2_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_VB2_H
+
+#include <linux/tracepoint.h>
+#include <media/videobuf2-core.h>
+
+DECLARE_EVENT_CLASS(vb2_event_class,
+	TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb),
+	TP_ARGS(q, vb),
+
+	TP_STRUCT__entry(
+		__field(void *, owner)
+		__field(u32, queued_count)
+		__field(int, owned_by_drv_count)
+		__field(u32, index)
+		__field(u32, type)
+		__field(u32, bytesused)
+		__field(u64, timestamp)
+	),
+
+	TP_fast_assign(
+		__entry->owner = q->owner;
+		__entry->queued_count = q->queued_count;
+		__entry->owned_by_drv_count =
+			atomic_read(&q->owned_by_drv_count);
+		__entry->index = vb->index;
+		__entry->type = vb->type;
+		__entry->bytesused = vb->planes[0].bytesused;
+		__entry->timestamp = vb->timestamp;
+	),
+
+	TP_printk("owner = %p, queued = %u, owned_by_drv = %d, index = %u, "
+		  "type = %u, bytesused = %u, timestamp = %llu", __entry->owner,
+		  __entry->queued_count,
+		  __entry->owned_by_drv_count,
+		  __entry->index, __entry->type,
+		  __entry->bytesused,
+		  __entry->timestamp
+	)
+)
+
+DEFINE_EVENT(vb2_event_class, vb2_buf_done,
+	TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb),
+	TP_ARGS(q, vb)
+);
+
+DEFINE_EVENT(vb2_event_class, vb2_buf_queue,
+	TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb),
+	TP_ARGS(q, vb)
+);
+
+DEFINE_EVENT(vb2_event_class, vb2_dqbuf,
+	TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb),
+	TP_ARGS(q, vb)
+);
+
+DEFINE_EVENT(vb2_event_class, vb2_qbuf,
+	TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb),
+	TP_ARGS(q, vb)
+);
+
+#endif /* if !defined(_TRACE_VB2_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>