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, 35 insertions, 0 deletions

diff --git a/include/uapi/asm-generic/int-l64.h b/include/uapi/asm-generic/int-l64.h
new file mode 100644
index 000000000..ed8bcd99c
--- /dev/null
+++ b/include/uapi/asm-generic/int-l64.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * asm-generic/int-l64.h
+ *
+ * Integer declarations for architectures which use "long"
+ * for 64-bit types.
+ */
+
+#ifndef _UAPI_ASM_GENERIC_INT_L64_H
+#define _UAPI_ASM_GENERIC_INT_L64_H
+
+#include <asm/bitsperlong.h>
+
+#ifndef __ASSEMBLY__
+/*
+ * __xx is ok: it doesn't pollute the POSIX namespace. Use these in the
+ * header files exported to user space
+ */
+
+typedef __signed__ char __s8;
+typedef unsigned char __u8;
+
+typedef __signed__ short __s16;
+typedef unsigned short __u16;
+
+typedef __signed__ int __s32;
+typedef unsigned int __u32;
+
+typedef __signed__ long __s64;
+typedef unsigned long __u64;
+
+#endif /* __ASSEMBLY__ */
+
+
+#endif /* _UAPI_ASM_GENERIC_INT_L64_H */