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, 51 insertions, 0 deletions

diff --git a/drivers/usb/common/Kconfig b/drivers/usb/common/Kconfig
new file mode 100644
index 000000000..b85662243
--- /dev/null
+++ b/drivers/usb/common/Kconfig
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config USB_COMMON
+	tristate
+
+
+config USB_LED_TRIG
+	bool "USB LED Triggers"
+	depends on LEDS_CLASS && USB_COMMON && LEDS_TRIGGERS
+	help
+	  This option adds LED triggers for USB host and/or gadget activity.
+
+	  Say Y here if you are working on a system with led-class supported
+	  LEDs and you want to use them as activity indicators for USB host or
+	  gadget.
+
+config USB_ULPI_BUS
+	tristate "USB ULPI PHY interface support"
+	select USB_COMMON
+	help
+	  UTMI+ Low Pin Interface (ULPI) is specification for a commonly used
+	  USB 2.0 PHY interface. The ULPI specification defines a standard set
+	  of registers that can be used to detect the vendor and product which
+	  allows ULPI to be handled as a bus. This module is the driver for that
+	  bus.
+
+	  The ULPI interfaces (the buses) are registered by the drivers for USB
+	  controllers which support ULPI register access and have ULPI PHY
+	  attached to them. The ULPI PHY drivers themselves are normal PHY
+	  drivers.
+
+	  ULPI PHYs provide often functions such as ADP sensing/probing (OTG
+	  protocol) and USB charger detection.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called ulpi.
+
+config USB_CONN_GPIO
+	tristate "USB GPIO Based Connection Detection Driver"
+	depends on GPIOLIB
+	select USB_ROLE_SWITCH
+	select POWER_SUPPLY
+	help
+	  The driver supports USB role switch between host and device via GPIO
+	  based USB cable detection, used typically if an input GPIO is used
+	  to detect USB ID pin, and another input GPIO may be also used to detect
+	  Vbus pin at the same time, it also can be used to enable/disable
+	  device if an input GPIO is only used to detect Vbus pin.
+
+	  To compile the driver as a module, choose M here: the module will
+	  be called usb-conn-gpio.ko