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, 55 insertions, 0 deletions

diff --git a/include/scsi/scsi_ioctl.h b/include/scsi/scsi_ioctl.h
new file mode 100644
index 000000000..a207c07da
--- /dev/null
+++ b/include/scsi/scsi_ioctl.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SCSI_IOCTL_H
+#define _SCSI_IOCTL_H 
+
+#define SCSI_IOCTL_SEND_COMMAND 1
+#define SCSI_IOCTL_TEST_UNIT_READY 2
+#define SCSI_IOCTL_BENCHMARK_COMMAND 3
+#define SCSI_IOCTL_SYNC 4			/* Request synchronous parameters */
+#define SCSI_IOCTL_START_UNIT 5
+#define SCSI_IOCTL_STOP_UNIT 6
+/* The door lock/unlock constants are compatible with Sun constants for
+   the cdrom */
+#define SCSI_IOCTL_DOORLOCK 0x5380		/* lock the eject mechanism */
+#define SCSI_IOCTL_DOORUNLOCK 0x5381		/* unlock the mechanism	  */
+
+#define	SCSI_REMOVAL_PREVENT	1
+#define	SCSI_REMOVAL_ALLOW	0
+
+#ifdef __KERNEL__
+
+struct gendisk;
+struct scsi_device;
+struct sg_io_hdr;
+
+/*
+ * Structures used for scsi_ioctl et al.
+ */
+
+typedef struct scsi_ioctl_command {
+	unsigned int inlen;
+	unsigned int outlen;
+	unsigned char data[];
+} Scsi_Ioctl_Command;
+
+typedef struct scsi_idlun {
+	__u32 dev_id;
+	__u32 host_unique_id;
+} Scsi_Idlun;
+
+/* Fibre Channel WWN, port_id struct */
+typedef struct scsi_fctargaddress {
+	__u32 host_port_id;
+	unsigned char host_wwn[8]; // include NULL term.
+} Scsi_FCTargAddress;
+
+int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev,
+		int cmd, bool ndelay);
+int scsi_ioctl(struct scsi_device *sdev, bool open_for_write, int cmd,
+		void __user *arg);
+int get_sg_io_hdr(struct sg_io_hdr *hdr, const void __user *argp);
+int put_sg_io_hdr(const struct sg_io_hdr *hdr, void __user *argp);
+bool scsi_cmd_allowed(unsigned char *cmd, bool open_for_write);
+
+#endif /* __KERNEL__ */
+#endif /* _SCSI_IOCTL_H */