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, 36 insertions, 0 deletions

diff --git a/include/uapi/asm-generic/Kbuild b/include/uapi/asm-generic/Kbuild
new file mode 100644
index 000000000..ebb180aac
--- /dev/null
+++ b/include/uapi/asm-generic/Kbuild
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Headers that are mandatory in usr/include/asm/
+# (This file is not included when SRCARCH=um since UML does not support UAPI.)
+
+mandatory-y += auxvec.h
+mandatory-y += bitsperlong.h
+mandatory-y += bpf_perf_event.h
+mandatory-y += byteorder.h
+mandatory-y += errno.h
+mandatory-y += fcntl.h
+mandatory-y += ioctl.h
+mandatory-y += ioctls.h
+mandatory-y += ipcbuf.h
+mandatory-y += mman.h
+mandatory-y += msgbuf.h
+mandatory-y += param.h
+mandatory-y += poll.h
+mandatory-y += posix_types.h
+mandatory-y += ptrace.h
+mandatory-y += resource.h
+mandatory-y += sembuf.h
+mandatory-y += setup.h
+mandatory-y += shmbuf.h
+mandatory-y += sigcontext.h
+mandatory-y += siginfo.h
+mandatory-y += signal.h
+mandatory-y += socket.h
+mandatory-y += sockios.h
+mandatory-y += stat.h
+mandatory-y += statfs.h
+mandatory-y += swab.h
+mandatory-y += termbits.h
+mandatory-y += termios.h
+mandatory-y += types.h
+mandatory-y += unistd.h