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, 66 insertions, 0 deletions

diff --git a/drivers/hid/hid-sunplus.c b/drivers/hid/hid-sunplus.c
new file mode 100644
index 000000000..64e4cff8c
--- /dev/null
+++ b/drivers/hid/hid-sunplus.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID driver for some sunplus "special" devices
+ *
+ *  Copyright (c) 1999 Andreas Gal
+ *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
+ *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
+ *  Copyright (c) 2006-2007 Jiri Kosina
+ *  Copyright (c) 2008 Jiri Slaby
+ */
+
+/*
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+static const __u8 *sp_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
+{
+	if (*rsize >= 112 && rdesc[104] == 0x26 && rdesc[105] == 0x80 &&
+			rdesc[106] == 0x03) {
+		hid_info(hdev, "fixing up Sunplus Wireless Desktop report descriptor\n");
+		rdesc[105] = rdesc[110] = 0x03;
+		rdesc[106] = rdesc[111] = 0x21;
+	}
+	return rdesc;
+}
+
+#define sp_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
+		EV_KEY, (c))
+static int sp_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+		struct hid_field *field, struct hid_usage *usage,
+		unsigned long **bit, int *max)
+{
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_CONSUMER)
+		return 0;
+
+	switch (usage->hid & HID_USAGE) {
+	case 0x2003: sp_map_key_clear(KEY_ZOOMIN);		break;
+	case 0x2103: sp_map_key_clear(KEY_ZOOMOUT);	break;
+	default:
+		return 0;
+	}
+	return 1;
+}
+
+static const struct hid_device_id sp_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SUNPLUS, USB_DEVICE_ID_SUNPLUS_WDESKTOP) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, sp_devices);
+
+static struct hid_driver sp_driver = {
+	.name = "sunplus",
+	.id_table = sp_devices,
+	.report_fixup = sp_report_fixup,
+	.input_mapping = sp_input_mapping,
+};
+module_hid_driver(sp_driver);
+
+MODULE_DESCRIPTION("HID driver for some sunplus \"special\" devices");
+MODULE_LICENSE("GPL");