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, 70 insertions, 0 deletions

diff --git a/security/ipe/eval.h b/security/ipe/eval.h
new file mode 100644
index 000000000..fef65a364
--- /dev/null
+++ b/security/ipe/eval.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef _IPE_EVAL_H
+#define _IPE_EVAL_H
+
+#include <linux/file.h>
+#include <linux/types.h>
+
+#include "policy.h"
+#include "hooks.h"
+
+#define IPE_EVAL_CTX_INIT ((struct ipe_eval_ctx){ 0 })
+
+extern struct ipe_policy __rcu *ipe_active_policy;
+extern bool success_audit;
+extern bool enforce;
+
+struct ipe_superblock {
+	bool initramfs;
+};
+
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+struct ipe_bdev {
+#ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE
+	bool dm_verity_signed;
+#endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */
+	struct digest_info *root_hash;
+};
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+struct ipe_inode {
+	bool fs_verity_signed;
+};
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+
+struct ipe_eval_ctx {
+	enum ipe_op_type op;
+	enum ipe_hook_type hook;
+
+	const struct file *file;
+	bool initramfs;
+#ifdef CONFIG_IPE_PROP_DM_VERITY
+	const struct ipe_bdev *ipe_bdev;
+#endif /* CONFIG_IPE_PROP_DM_VERITY */
+#ifdef CONFIG_IPE_PROP_FS_VERITY
+	const struct inode *ino;
+#endif /* CONFIG_IPE_PROP_FS_VERITY */
+#ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
+	const struct ipe_inode *ipe_inode;
+#endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
+};
+
+enum ipe_match {
+	IPE_MATCH_RULE = 0,
+	IPE_MATCH_TABLE,
+	IPE_MATCH_GLOBAL,
+	__IPE_MATCH_MAX
+};
+
+void ipe_build_eval_ctx(struct ipe_eval_ctx *ctx,
+			const struct file *file,
+			enum ipe_op_type op,
+			enum ipe_hook_type hook);
+int ipe_evaluate_event(const struct ipe_eval_ctx *const ctx);
+
+#endif /* _IPE_EVAL_H */