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, 38 insertions, 0 deletions

diff --git a/drivers/net/pcs/Kconfig b/drivers/net/pcs/Kconfig
new file mode 100644
index 000000000..e417fd66f
--- /dev/null
+++ b/drivers/net/pcs/Kconfig
@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# PCS Layer Configuration
+#
+
+menu "PCS device drivers"
+
+config PCS_XPCS
+	tristate "Synopsys DesignWare Ethernet XPCS"
+	select PHYLINK
+	help
+	  This module provides a driver and helper functions for Synopsys
+	  DesignWare XPCS controllers.
+
+config PCS_LYNX
+	tristate
+	help
+	  This module provides helpers to phylink for managing the Lynx PCS
+	  which is part of the Layerscape and QorIQ Ethernet SERDES.
+
+config PCS_MTK_LYNXI
+	tristate
+	select PHY_COMMON_PROPS
+	select REGMAP
+	help
+	  This module provides helpers to phylink for managing the LynxI PCS
+	  which is part of MediaTek's SoC and Ethernet switch ICs.
+
+config PCS_RZN1_MIIC
+	tristate "Renesas RZ/N1, RZ/N2H, RZ/T2H MII converter"
+	depends on OF
+	depends on ARCH_RENESAS || COMPILE_TEST
+	help
+	  This module provides a driver for the MII converter available on
+	  Renesas RZ/N1, RZ/N2H, and RZ/T2H SoCs. This PCS converts MII to
+	  RMII/RGMII, or can be set in pass-through mode for MII.
+
+endmenu