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, 63 insertions, 0 deletions

diff --git a/include/video/sa1100fb.h b/include/video/sa1100fb.h
new file mode 100644
index 000000000..4ab409653
--- /dev/null
+++ b/include/video/sa1100fb.h
@@ -0,0 +1,63 @@
+/*
+ * StrongARM 1100 LCD Controller Frame Buffer Device
+ *
+ * Copyright (C) 1999 Eric A. Thomas
+ *  Based on acornfb.c Copyright (C) Russell King.
+ *  
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+#ifndef _VIDEO_SA1100FB_H
+#define _VIDEO_SA1100FB_H
+
+#include <linux/fb.h>
+#include <linux/types.h>
+
+#define RGB_4	0
+#define RGB_8	1
+#define RGB_16	2
+#define NR_RGB	3
+
+/* These are the bitfields for each display depth that we support. */
+struct sa1100fb_rgb {
+	struct fb_bitfield	red;
+	struct fb_bitfield	green;
+	struct fb_bitfield	blue;
+	struct fb_bitfield	transp;
+};
+
+/* This structure describes the machine which we are running on. */
+struct sa1100fb_mach_info {
+	u_long		pixclock;
+
+	u_short		xres;
+	u_short		yres;
+
+	u_char		bpp;
+	u_char		hsync_len;
+	u_char		left_margin;
+	u_char		right_margin;
+
+	u_char		vsync_len;
+	u_char		upper_margin;
+	u_char		lower_margin;
+	u_char		sync;
+
+	u_int		cmap_greyscale:1,
+			cmap_inverse:1,
+			cmap_static:1,
+			unused:29;
+
+	u_int		lccr0;
+	u_int		lccr3;
+
+	/* Overrides for the default RGB maps */
+	const struct sa1100fb_rgb *rgb[NR_RGB];
+
+	void (*backlight_power)(int);
+	void (*lcd_power)(int);
+	void (*set_visual)(u32);
+};
+
+#endif