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, 98 insertions, 0 deletions

diff --git a/drivers/hid/hid-glorious.c b/drivers/hid/hid-glorious.c
new file mode 100644
index 000000000..5bbd81248
--- /dev/null
+++ b/drivers/hid/hid-glorious.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  USB HID driver for Glorious PC Gaming Race
+ *  Glorious Model O, O- and D mice.
+ *
+ *  Copyright (c) 2020 Samuel Čavoj <sammko@sammserver.com>
+ */
+
+/*
+ */
+
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+MODULE_AUTHOR("Samuel Čavoj <sammko@sammserver.com>");
+MODULE_DESCRIPTION("HID driver for Glorious PC Gaming Race mice");
+
+/*
+ * Glorious Model O and O- specify the const flag in the consumer input
+ * report descriptor, which leads to inputs being ignored. Fix this
+ * by patching the descriptor.
+ *
+ * Glorious Model I incorrectly specifes the Usage Minimum for its
+ * keyboard HID report, causing keycodes to be misinterpreted.
+ * Fix this by setting Usage Minimum to 0 in that report.
+ */
+static const __u8 *glorious_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
+{
+	if (*rsize == 213 &&
+		rdesc[84] == 129 && rdesc[112] == 129 && rdesc[140] == 129 &&
+		rdesc[85] == 3   && rdesc[113] == 3   && rdesc[141] == 3) {
+		hid_info(hdev, "patching Glorious Model O consumer control report descriptor\n");
+		rdesc[85] = rdesc[113] = rdesc[141] = \
+			HID_MAIN_ITEM_VARIABLE | HID_MAIN_ITEM_RELATIVE;
+	}
+	if (*rsize == 156 && rdesc[41] == 1) {
+		hid_info(hdev, "patching Glorious Model I keyboard report descriptor\n");
+		rdesc[41] = 0;
+	}
+	return rdesc;
+}
+
+static void glorious_update_name(struct hid_device *hdev)
+{
+	const char *model = "Device";
+
+	switch (hdev->product) {
+	case USB_DEVICE_ID_GLORIOUS_MODEL_O:
+		model = "Model O"; break;
+	case USB_DEVICE_ID_GLORIOUS_MODEL_D:
+		model = "Model D"; break;
+	case USB_DEVICE_ID_GLORIOUS_MODEL_I:
+		model = "Model I"; break;
+	}
+
+	snprintf(hdev->name, sizeof(hdev->name), "%s %s", "Glorious", model);
+}
+
+static int glorious_probe(struct hid_device *hdev,
+		const struct hid_device_id *id)
+{
+	int ret;
+
+	hdev->quirks |= HID_QUIRK_INPUT_PER_APP;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return ret;
+
+	glorious_update_name(hdev);
+
+	return hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+}
+
+static const struct hid_device_id glorious_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SINOWEALTH,
+		USB_DEVICE_ID_GLORIOUS_MODEL_O) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SINOWEALTH,
+		USB_DEVICE_ID_GLORIOUS_MODEL_D) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_LAVIEW,
+		USB_DEVICE_ID_GLORIOUS_MODEL_I) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, glorious_devices);
+
+static struct hid_driver glorious_driver = {
+	.name = "glorious",
+	.id_table = glorious_devices,
+	.probe = glorious_probe,
+	.report_fixup = glorious_report_fixup
+};
+
+module_hid_driver(glorious_driver);
+
+MODULE_LICENSE("GPL");