scsi-disk: add SCSI_DISK_QUIRK_MODE_PAGE_VENDOR_SPECIFIC_APPLE quirk for Macintosh

Both MacOS and A/UX make use of vendor-specific MODE SELECT commands with PF=0
to identify SCSI devices:

- MacOS sends a MODE SELECT command with PF=0 for the MODE_PAGE_VENDOR_SPECIFIC
  (0x0) mode page containing 2 bytes before initialising a disk

- A/UX (installed on disk) sends a MODE SELECT command with PF=0 during SCSI
  bus enumeration, and gets stuck in an infinite loop if it fails

Add a new SCSI_DISK_QUIRK_MODE_PAGE_VENDOR_SPECIFIC_APPLE quirk to allow both
PF=0 MODE SELECT commands and implement a MODE_PAGE_VENDOR_SPECIFIC (0x0)
mode page which is compatible with MacOS.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20220622105314.802852-7-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 28 insertions, 2 deletions

diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index b1d08bfba5..2cdbba7ccc 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -1079,6 +1079,7 @@ static int mode_sense_page(SCSIDiskState *s, int page, uint8_t **p_outbuf,
                            int page_control)
 {
     static const int mode_sense_valid[0x3f] = {
+        [MODE_PAGE_VENDOR_SPECIFIC]        = (1 << TYPE_DISK) | (1 << TYPE_ROM),
         [MODE_PAGE_HD_GEOMETRY]            = (1 << TYPE_DISK),
         [MODE_PAGE_FLEXIBLE_DISK_GEOMETRY] = (1 << TYPE_DISK),
         [MODE_PAGE_CACHING]                = (1 << TYPE_DISK) | (1 << TYPE_ROM),
@@ -1244,6 +1245,22 @@ static int mode_sense_page(SCSIDiskState *s, int page, uint8_t **p_outbuf,
             return -1;
         }
 
+    case MODE_PAGE_VENDOR_SPECIFIC:
+        if (s->qdev.type == TYPE_DISK && (s->quirks &
+            (1 << SCSI_DISK_QUIRK_MODE_PAGE_VENDOR_SPECIFIC_APPLE))) {
+            length = 0x2;
+            if (page_control == 1) { /* Changeable Values */
+                p[0] = 0xff;
+                p[1] = 0xff;
+                break;
+            }
+            p[0] = 0;
+            p[1] = 0;
+            break;
+        } else {
+            return -1;
+        }
+
     default:
         return -1;
     }
@@ -1570,9 +1587,12 @@ static void scsi_disk_emulate_mode_select(SCSIDiskReq *r, uint8_t *inbuf)
     int bd_len;
     int pass;
 
-    /* We only support PF=1, SP=0.  */
     if ((r->req.cmd.buf[1] & 0x11) != 0x10) {
-        goto invalid_field;
+        if (!(s->quirks &
+            (1 << SCSI_DISK_QUIRK_MODE_PAGE_VENDOR_SPECIFIC_APPLE))) {
+            /* We only support PF=1, SP=0.  */
+            goto invalid_field;
+        }
     }
 
     if (len < hdr_len) {
@@ -3069,6 +3089,9 @@ static Property scsi_hd_properties[] = {
     DEFINE_PROP_UINT16("rotation_rate", SCSIDiskState, rotation_rate, 0),
     DEFINE_PROP_INT32("scsi_version", SCSIDiskState, qdev.default_scsi_version,
                       5),
+    DEFINE_PROP_BIT("quirk_mode_page_vendor_specific_apple", SCSIDiskState,
+                    quirks, SCSI_DISK_QUIRK_MODE_PAGE_VENDOR_SPECIFIC_APPLE,
+                    0),
     DEFINE_BLOCK_CHS_PROPERTIES(SCSIDiskState, qdev.conf),
     DEFINE_PROP_END_OF_LIST(),
 };
@@ -3121,6 +3144,9 @@ static Property scsi_cd_properties[] = {
                     SCSI_DISK_QUIRK_MODE_PAGE_APPLE_VENDOR, 0),
     DEFINE_PROP_BIT("quirk_mode_sense_rom_use_dbd", SCSIDiskState, quirks,
                     SCSI_DISK_QUIRK_MODE_SENSE_ROM_USE_DBD, 0),
+    DEFINE_PROP_BIT("quirk_mode_page_vendor_specific_apple", SCSIDiskState,
+                    quirks, SCSI_DISK_QUIRK_MODE_PAGE_VENDOR_SPECIFIC_APPLE,
+                    0),
     DEFINE_PROP_END_OF_LIST(),
 };