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, 27 insertions, 0 deletions

diff --git a/include/acpi/acpi_io.h b/include/acpi/acpi_io.h
new file mode 100644
index 000000000..027faa888
--- /dev/null
+++ b/include/acpi/acpi_io.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ACPI_IO_H_
+#define _ACPI_IO_H_
+
+#include <linux/io.h>
+
+#include <asm/acpi.h>
+
+#ifndef acpi_os_ioremap
+static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys,
+					    acpi_size size)
+{
+       return ioremap_cache(phys, size);
+}
+#endif
+
+extern bool acpi_permanent_mmap;
+
+void __iomem __ref
+*acpi_os_map_iomem(acpi_physical_address phys, acpi_size size);
+void __ref acpi_os_unmap_iomem(void __iomem *virt, acpi_size size);
+void __iomem *acpi_os_get_iomem(acpi_physical_address phys, unsigned int size);
+
+void __iomem *acpi_os_map_generic_address(struct acpi_generic_address *addr);
+void acpi_os_unmap_generic_address(struct acpi_generic_address *addr);
+
+#endif