[PATCH 1/1] linux-user: Add support for SG_IO and SG_GET_VERSION_NUM raw SCSI ioctls

[Leif N Huhn]

This patch implements functionalities of following ioctls:

SG_GET_VERSION_NUM - Returns SG driver version number

    The sg version numbers are of the form "x.y.z" and the single number given
    by the SG_GET_VERSION_NUM ioctl() is calculated by
    (x * 10000 + y * 100 + z).

SG_IO - Permits user applications to send SCSI commands to a device

    It is logically equivalent to a write followed by a read.

Implementation notes:

    For SG_GET_VERSION_NUM the value is an int and the implementation is
    straightforward.

    For SG_IO, the generic thunk mechanism is used, and works correctly when
    the host and guest architecture have the same pointer size. A special ioctl
    handler may be needed in other situations and is not covered in this
    implementation.

Signed-off-by: Leif N Huhn <leif.n.huhn@gmail.com>
---
 linux-user/ioctls.h        |  2 ++
 linux-user/syscall.c       |  1 +
 linux-user/syscall_defs.h  | 33 +++++++++++++++++++++++++++++++++
 linux-user/syscall_types.h |  5 +++++
 4 files changed, 41 insertions(+)

diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h
index 0713ae1311..92e2f65e05 100644
--- a/linux-user/ioctls.h
+++ b/linux-user/ioctls.h
@@ -333,6 +333,8 @@
   IOCTL(CDROM_DRIVE_STATUS, 0, TYPE_NULL)
   IOCTL(CDROM_DISC_STATUS, 0, TYPE_NULL)
   IOCTL(CDROMAUDIOBUFSIZ, 0, TYPE_INT)
+  IOCTL(SG_GET_VERSION_NUM, 0, TYPE_INT)
+  IOCTL(SG_IO, IOC_RW, MK_PTR(MK_STRUCT(STRUCT_sg_io_hdr)))
 
 #if 0
   IOCTL(SNDCTL_COPR_HALT, IOC_RW, MK_PTR(TYPE_INT))
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 945fc25279..d846ef1af2 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -115,6 +115,7 @@
 #ifdef HAVE_DRM_H
 #include <libdrm/drm.h>
 #endif
+#include <scsi/sg.h>
 #include "linux_loop.h"
 #include "uname.h"
 
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index 3c261cff0e..0e3004eb31 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -2774,4 +2774,37 @@ struct target_statx {
    /* 0x100 */
 };
 
+/* from kernel's include/scsi/sg.h */
+
+#define TARGET_SG_GET_VERSION_NUM 0x2282 /* Example: version 2.1.34 yields 
20134 */
+/* synchronous SCSI command ioctl, (only in version 3 interface) */
+#define TARGET_SG_IO 0x2285   /* similar effect as write() followed by read() 
*/
+
+struct target_sg_io_hdr
+{
+    int interface_id;           /* [i] 'S' for SCSI generic (required) */
+    int dxfer_direction;        /* [i] data transfer direction  */
+    unsigned char cmd_len;      /* [i] SCSI command length */
+    unsigned char mx_sb_len;    /* [i] max length to write to sbp */
+    unsigned short iovec_count; /* [i] 0 implies no scatter gather */
+    unsigned int dxfer_len;     /* [i] byte count of data transfer */
+    abi_ulong    dxferp;       /* [i], [*io] points to data transfer memory
+                                             or scatter gather list */
+    abi_ulong    cmdp;          /* [i], [*i] points to command to perform */
+    abi_ulong    sbp;          /* [i], [*o] points to sense_buffer memory */
+    unsigned int timeout;       /* [i] MAX_UINT->no timeout (unit: millisec) */
+    unsigned int flags;         /* [i] 0 -> default, see SG_FLAG... */
+    int pack_id;                /* [i->o] unused internally (normally) */
+    abi_ulong     usr_ptr;      /* [i->o] unused internally */
+    unsigned char status;       /* [o] scsi status */
+    unsigned char masked_status;/* [o] shifted, masked scsi status */
+    unsigned char msg_status;   /* [o] messaging level data (optional) */
+    unsigned char sb_len_wr;    /* [o] byte count actually written to sbp */
+    unsigned short host_status; /* [o] errors from host adapter */
+    unsigned short driver_status;/* [o] errors from software driver */
+    int resid;                  /* [o] dxfer_len - actual_transferred */
+    unsigned int duration;      /* [o] time taken by cmd (unit: millisec) */
+    unsigned int info;          /* [o] auxiliary information */
+};  /* 64 bytes long (on i386) */
+
 #endif
diff --git a/linux-user/syscall_types.h b/linux-user/syscall_types.h
index 3f1f033464..3752d217e2 100644
--- a/linux-user/syscall_types.h
+++ b/linux-user/syscall_types.h
@@ -59,6 +59,11 @@ STRUCT(cdrom_read_audio,
        TYPE_CHAR, TYPE_CHAR, TYPE_CHAR, TYPE_CHAR, TYPE_CHAR, TYPE_INT, 
TYPE_PTRVOID,
        TYPE_NULL)
 
+STRUCT(sg_io_hdr,
+       TYPE_INT, TYPE_INT, TYPE_CHAR, TYPE_CHAR, TYPE_SHORT, TYPE_INT, 
TYPE_PTRVOID,
+       TYPE_PTRVOID, TYPE_PTRVOID, TYPE_INT, TYPE_INT, TYPE_INT, TYPE_PTRVOID, 
TYPE_CHAR,
+       TYPE_CHAR, TYPE_CHAR, TYPE_CHAR, TYPE_SHORT, TYPE_SHORT, TYPE_INT, 
TYPE_INT, TYPE_INT)
+
 STRUCT(hd_geometry,
        TYPE_CHAR, TYPE_CHAR, TYPE_SHORT, TYPE_ULONG)
 
-- 
2.28.0