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, 88 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/fuse/nvidia,tegra20-fuse.yaml b/Documentation/devicetree/bindings/fuse/nvidia,tegra20-fuse.yaml
new file mode 100644
index 000000000..02f0b0462
--- /dev/null
+++ b/Documentation/devicetree/bindings/fuse/nvidia,tegra20-fuse.yaml
@@ -0,0 +1,88 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/fuse/nvidia,tegra20-fuse.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVIDIA Tegra FUSE block
+
+maintainers:
+  - Thierry Reding <thierry.reding@gmail.com>
+  - Jon Hunter <jonathanh@nvidia.com>
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - nvidia,tegra20-efuse
+          - nvidia,tegra30-efuse
+          - nvidia,tegra114-efuse
+          - nvidia,tegra124-efuse
+          - nvidia,tegra210-efuse
+          - nvidia,tegra186-efuse
+          - nvidia,tegra194-efuse
+          - nvidia,tegra234-efuse
+
+      - items:
+          - const: nvidia,tegra132-efuse
+          - const: nvidia,tegra124-efuse
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: fuse
+
+  resets:
+    maxItems: 1
+
+  reset-names:
+    items:
+      - const: fuse
+
+  operating-points-v2: true
+
+  power-domains:
+    items:
+      - description: phandle to the core power domain
+
+additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+
+if:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - nvidia,tegra20-efuse
+          - nvidia,tegra30-efuse
+          - nvidia,tegra114-efuse
+          - nvidia,tegra124-efuse
+          - nvidia,tegra132-efuse
+          - nvidia,tegra210-efuse
+then:
+  required:
+    - resets
+    - reset-names
+
+examples:
+  - |
+    #include <dt-bindings/clock/tegra20-car.h>
+
+    fuse@7000f800 {
+        compatible = "nvidia,tegra20-efuse";
+        reg = <0x7000f800 0x400>;
+        clocks = <&tegra_car TEGRA20_CLK_FUSE>;
+        clock-names = "fuse";
+        resets = <&tegra_car 39>;
+        reset-names = "fuse";
+    };