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, 82 insertions, 0 deletions

diff --git a/drivers/hid/hid-topseed.c b/drivers/hid/hid-topseed.c
new file mode 100644
index 000000000..645e36cd8
--- /dev/null
+++ b/drivers/hid/hid-topseed.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  HID driver for TopSeed Cyberlink remote
+ *
+ *  Copyright (c) 2008 Lev Babiev
+ *  based on hid-cherry driver
+ *
+ *  Modified to also support BTC "Emprex 3009URF III Vista MCE Remote" by
+ *  Wayne Thomas 2010.
+ *
+ *  Modified to support Conceptronic CLLRCMCE by
+ *  Kees Bakker 2010.
+ */
+
+/*
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define ts_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
+					EV_KEY, (c))
+static int ts_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_LOGIVENDOR)
+		return 0;
+
+	switch (usage->hid & HID_USAGE) {
+	case 0x00c: ts_map_key_clear(KEY_WLAN);		break;
+	case 0x00d: ts_map_key_clear(KEY_MEDIA);	break;
+	case 0x010: ts_map_key_clear(KEY_ZOOM);		break;
+	case 0x024: ts_map_key_clear(KEY_MENU);		break;
+	case 0x025: ts_map_key_clear(KEY_TV);		break;
+	case 0x027: ts_map_key_clear(KEY_MODE);		break;
+	case 0x031: ts_map_key_clear(KEY_AUDIO);	break;
+	case 0x032: ts_map_key_clear(KEY_TEXT);		break;
+	case 0x033: ts_map_key_clear(KEY_CHANNEL);	break;
+	case 0x047: ts_map_key_clear(KEY_MP3);		break;
+	case 0x048: ts_map_key_clear(KEY_TV2);		break;
+	case 0x049: ts_map_key_clear(KEY_CAMERA);	break;
+	case 0x04a: ts_map_key_clear(KEY_VIDEO);	break;
+	case 0x04b: ts_map_key_clear(KEY_ANGLE);	break;
+	case 0x04c: ts_map_key_clear(KEY_LANGUAGE);	break;
+	case 0x04d: ts_map_key_clear(KEY_SUBTITLE);	break;
+	case 0x050: ts_map_key_clear(KEY_RADIO);	break;
+	case 0x05a: ts_map_key_clear(KEY_TEXT);		break;
+	case 0x05b: ts_map_key_clear(KEY_RED);		break;
+	case 0x05c: ts_map_key_clear(KEY_GREEN);	break;
+	case 0x05d: ts_map_key_clear(KEY_YELLOW);	break;
+	case 0x05e: ts_map_key_clear(KEY_BLUE);		break;
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+static const struct hid_device_id ts_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_TOPSEED, USB_DEVICE_ID_TOPSEED_CYBERLINK) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_BTC, USB_DEVICE_ID_BTC_EMPREX_REMOTE) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_BTC, USB_DEVICE_ID_BTC_EMPREX_REMOTE_2) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_TOPSEED2, USB_DEVICE_ID_TOPSEED2_RF_COMBO) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_TOSHIBA_WT10A) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, ts_devices);
+
+static struct hid_driver ts_driver = {
+	.name = "topseed",
+	.id_table = ts_devices,
+	.input_mapping = ts_input_mapping,
+};
+module_hid_driver(ts_driver);
+
+MODULE_DESCRIPTION("HID driver for TopSeed Cyberlink remote");
+MODULE_LICENSE("GPL");