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, 203 insertions, 0 deletions

diff --git a/Documentation/sphinx-static/custom.css b/Documentation/sphinx-static/custom.css
new file mode 100644
index 000000000..6c03dca44
--- /dev/null
+++ b/Documentation/sphinx-static/custom.css
@@ -0,0 +1,203 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * CSS tweaks for the Alabaster theme
+ */
+
+div.body {  max-width: 120em; }
+
+/* Shrink the headers a bit */
+div.body h1 { font-size: 180%; }
+div.body h2 { font-size: 150%; }
+div.body h3 { font-size: 130%; }
+div.body h4 { font-size: 110%; }
+
+/* toctree captions are styled like h2 */
+div.toctree-wrapper p.caption[role=heading] { font-size: 150%; }
+
+/* Tighten up the layout slightly */
+div.body { padding: 0 15px 0 10px; }
+div.sphinxsidebarwrapper { padding: 1em 0.4em; }
+div.sphinxsidebar { font-size: inherit;
+		    max-height: 100%;
+		    overflow-y: auto; }
+/* Tweak document margins and don't force width */
+div.document {
+    margin: 20px 10px 0 10px;
+    width: auto;
+}
+
+/* Size the logo appropriately */
+img.logo {
+    width: 104px;
+    margin-bottom: 20px;
+}
+
+/* The default is to use -1em, which makes it override text */
+li { text-indent: 0em; }
+
+/*
+ * Parameters for the display of function prototypes and such included
+ * from C source files.
+ */
+dl.function, dl.struct, dl.enum { margin-top: 2em; background-color: #ecf0f3; }
+/* indent lines 2+ of multi-line function prototypes */
+dl.function dt { margin-left: 10em; text-indent: -10em; }
+/*
+ * Preserve C API signatures on one line and apply contained horizontal
+ * scrolling to prevent them from exceeding their container width and
+ * breaking page layout.
+ */
+dl.c { overflow-x: auto; overflow-y: hidden; }
+dl.c > dt.sig.sig-object { white-space: nowrap; }
+dt.sig-object { font-size: larger; }
+div.kernelindent { margin-left: 2em; margin-right: 4em; }
+
+/*
+ * Parameters for the display of function prototypes and such included
+ * from Python source files.
+ */
+dl.py { margin-top: 2em; background-color: #ecf0f3; }
+dl.py.class { margin-left: 2em; text-indent: -2em; padding-left: 2em; }
+dl.py.method, dl.py.attribute { margin-left: 2em; text-indent: -2em; }
+dl.py li, pre { text-indent: 0em; padding-left: 0 !important; }
+
+/*
+ * Tweaks for our local TOC
+ */
+div.kerneltoc li.toctree-l1 { font-size: smaller;
+		text-indent: -1em;
+		margin-left: 1em; }
+div.kerneltoc li.current > a {font-weight: bold; }
+div.kerneltoc li.toctree-l2,li.toctree-l3 { font-size: small;
+		text-indent: -1em;
+		margin-left: 1em;
+		list-style-type: none;
+	      }
+div.kerneltoc li.current ul { margin-left: 0; }
+div.kerneltoc { background-color: #eeeeee; }
+div.kerneltoc li.current ul { background-color: white; }
+
+/*
+ * Hide toctree captions on the welcome page, they should only be shown in the
+ * sidebar.
+ */
+section#the-linux-kernel-documentation p.caption { display: none; }
+
+/*
+ * Make section titles bold in the sidebar, and decrease their bottom margin to
+ * group them with their subsections.
+ */
+div.sphinxsidebar p.caption { font-weight: bold; margin-bottom: 0; }
+div.sphinxsidebar p.caption + ul { margin-top: 0; }
+
+/*
+ * The CSS magic to toggle the contents on small screens.
+ */
+label.kernel-toc-title { display: none; }
+label.kernel-toc-title:after {
+    content: "[Hide]";
+}
+input[type=checkbox]:checked ~ label.kernel-toc-title:after {
+    content: "[Show]";
+}
+/* Hide the toggle on large screens */
+input.kernel-toc-toggle { display: none; }
+
+/*
+ * Show and implement the toggle on small screens.
+ * The 875px width seems to be wired into alabaster.
+ */
+@media screen and (max-width: 875px) {
+    label.kernel-toc-title { display: inline;
+			     font-weight: bold;
+			     font-size: larger; }
+    input[type=checkbox]:checked ~ div.kerneltoc {
+	display: none;
+    }
+    h3.kernel-toc-contents { display: inline; }
+    div.kerneltoc a { color: black; }
+}
+
+/* Language selection menu */
+
+div.admonition {
+    /*
+     * Make sure we don't overlap notes and warnings at the top of the
+     * document.
+     */
+    clear: both;
+}
+
+div.language-selection {
+    background: #eeeeee;
+    border: 1px solid #cccccc;
+    margin-bottom: 1em;
+    padding: .5em;
+
+    position: relative;
+    float: right;
+}
+
+div.language-selection a {
+    display: block;
+    padding: 0.5em;
+    color: #333333;
+    text-decoration: none;
+}
+
+div.language-selection ul {
+    display: none;
+    position: absolute;
+
+    /* Align with the parent div */
+    top: 100%;
+    right: 0;
+    margin: 0;
+
+    list-style: none;
+
+    background: #fafafa;
+    border: 1px solid #cccccc;
+
+    /* Never break menu item lines */
+    white-space: nowrap;
+}
+
+div.language-selection:hover ul {
+    display: block;
+}
+
+div.language-selection ul li:hover {
+    background: #dddddd;
+}
+
+/* Let rendered reference links in tables wrap when needed. */
+div.body table.docutils a.reference {
+    overflow-wrap: anywhere;
+}
+
+/* Let long link text wrap instead of forcing overflow. */
+a {
+    overflow-wrap: anywhere;
+}
+
+/* Make xrefs more universally visible */
+a.reference, a.reference:hover {
+    border-bottom: none;
+    text-decoration: underline;
+    text-underline-offset: 0.3em;
+}
+
+/* Slightly different style for sidebar links */
+div.sphinxsidebar a { border-bottom: none; }
+div.sphinxsidebar a:hover {
+    border-bottom: none;
+    text-decoration: underline;
+    text-underline-offset: 0.3em;
+}
+
+a.manpage {
+	font-style: normal;
+	font-weight: bold;
+	font-family: "Courier New", Courier, monospace;
+}