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, 54 insertions, 0 deletions

diff --git a/drivers/pinctrl/devicetree.h b/drivers/pinctrl/devicetree.h
new file mode 100644
index 000000000..def76aba9
--- /dev/null
+++ b/drivers/pinctrl/devicetree.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Internal interface to pinctrl device tree integration
+ *
+ * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
+ */
+
+#include <linux/errno.h>
+
+struct device_node;
+struct of_phandle_args;
+
+struct pinctrl;
+struct pinctrl_dev;
+
+#ifdef CONFIG_OF
+
+void pinctrl_dt_free_maps(struct pinctrl *p);
+int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev);
+
+int pinctrl_count_index_with_args(const struct device_node *np,
+				  const char *list_name);
+
+int pinctrl_parse_index_with_args(const struct device_node *np,
+				  const char *list_name, int index,
+				  struct of_phandle_args *out_args);
+
+#else
+
+static inline int pinctrl_dt_to_map(struct pinctrl *p,
+				    struct pinctrl_dev *pctldev)
+{
+	return 0;
+}
+
+static inline void pinctrl_dt_free_maps(struct pinctrl *p)
+{
+}
+
+static inline int pinctrl_count_index_with_args(const struct device_node *np,
+						const char *list_name)
+{
+	return -ENODEV;
+}
+
+static inline int
+pinctrl_parse_index_with_args(const struct device_node *np,
+			      const char *list_name, int index,
+			      struct of_phandle_args *out_args)
+{
+	return -ENODEV;
+}
+
+#endif