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, 17 insertions, 0 deletions

diff --git a/Documentation/driver-api/80211/introduction.rst b/Documentation/driver-api/80211/introduction.rst
new file mode 100644
index 000000000..4938fa876
--- /dev/null
+++ b/Documentation/driver-api/80211/introduction.rst
@@ -0,0 +1,17 @@
+============
+Introduction
+============
+
+Explaining wireless 802.11 networking in the Linux kernel
+
+Copyright 2007-2009 Johannes Berg
+
+These books attempt to give a description of the various subsystems
+that play a role in 802.11 wireless networking in Linux. Since these
+books are for kernel developers they attempts to document the
+structures and functions used in the kernel as well as giving a
+higher-level overview.
+
+The reader is expected to be familiar with the 802.11 standard as
+published by the IEEE in 802.11-2007 (or possibly later versions).
+References to this standard will be given as "802.11-2007 8.1.5".