[Qemu-devel] [RFC] ide: multi-profile DVD-ROM support v2.1

[Carlo Marcelo Arenas Belon <carenas@sajinet.com.pe>]

This is version 2.1 of the patch to re-implement the "GET CONFIGURATION"
MMC-6 command as used by the IDE emulation to match the published SPEC
and that was originally published in :

  http://lists.gnu.org/archive/html/qemu-devel/2007-11/msg00849.html

Important changes from the previous patches :

* Use a 99min CD size as the bigger possible sector count for CD profile
* Don't recalculate the number of sectors
* Use an inline helper function to set the profiles in a cleaner way
* Avoid extra computations from constants except for #define values
* Reduce the use of magic numbers and use defines when possible

Remaining issues that will need to be addressed in future versions :

* MMC-6 also applies to SCSI devices and so the definitions might need
  to be moved to a common header when that code is developed.
* The use of the buffer might not be safe for unaligned access in some
  architectures, but the same applies to all other commands that are
  currently using the io_buffer directly as the hardware does.
* The heuristic used tries to guess the kind of media from the size of
  it and is not that reliable for really small DVDs that could fit in a
  CD.
* The response uses the io_buffer and is therefore limited to the size
  of it (not really a problem now when the maximum response size will
  be 20 bytes) but could be a problem when more features/profiles are
  implemented.
* When using the host_device driver media changes could go unnoticed
  and result in the wrong profile being selected due to limitations
  in the current implementation of the ide emulation.

Testing is appreciated

Carlo
---
Index: hw/ide.c
===================================================================
RCS file: /sources/qemu/qemu/hw/ide.c,v
retrieving revision 1.79
diff -u -p -r1.79 ide.c
--- hw/ide.c	24 Dec 2007 14:33:24 -0000	1.79
+++ hw/ide.c	8 Jan 2008 12:02:40 -0000
@@ -1,5 +1,5 @@
 /*
- * QEMU IDE disk and CD-ROM Emulator
+ * QEMU IDE disk and CD/DVD-ROM Emulator
  *
  * Copyright (c) 2003 Fabrice Bellard
  * Copyright (c) 2006 Openedhand Ltd.
@@ -284,6 +284,44 @@
  * of MODE_SENSE_POWER_PAGE */
 #define GPMODE_CDROM_PAGE		0x0d
 
+/* Some generally useful CD-ROM information */
+#define CD_MINS                       99 /* max. minutes per CD */
+#define CD_SECS                       60 /* seconds per minute */
+#define CD_FRAMES                     75 /* frames per second */
+#define CD_FRAMESIZE                2048 /* bytes per frame, "cooked" mode */
+#define CD_MAX_BYTES       (CD_MINS * CD_SECS * CD_FRAMES * CD_FRAMESIZE)
+#define CD_MAX_SECTORS     (CD_MAX_BYTES / 512)
+
+/* Profile list from MMC-6 revision 1 table 91 */
+#define MMC_PROFILE_NONE                0x0000
+#define MMC_PROFILE_CD_ROM              0x0008
+#define MMC_PROFILE_CD_R                0x0009
+#define MMC_PROFILE_CD_RW               0x000A
+#define MMC_PROFILE_DVD_ROM             0x0010
+#define MMC_PROFILE_DVD_R_SR            0x0011
+#define MMC_PROFILE_DVD_RAM             0x0012
+#define MMC_PROFILE_DVD_RW_RO           0x0013
+#define MMC_PROFILE_DVD_RW_SR           0x0014
+#define MMC_PROFILE_DVD_R_DL_SR         0x0015
+#define MMC_PROFILE_DVD_R_DL_JR         0x0016
+#define MMC_PROFILE_DVD_RW_DL           0x0017
+#define MMC_PROFILE_DVD_DDR             0x0018
+#define MMC_PROFILE_DVD_PLUS_RW         0x001A
+#define MMC_PROFILE_DVD_PLUS_R          0x001B
+#define MMC_PROFILE_DVD_PLUS_RW_DL      0x002A
+#define MMC_PROFILE_DVD_PLUS_R_DL       0x002B
+#define MMC_PROFILE_BD_ROM              0x0040
+#define MMC_PROFILE_BD_R_SRM            0x0041
+#define MMC_PROFILE_BD_R_RRM            0x0042
+#define MMC_PROFILE_BD_RE               0x0043
+#define MMC_PROFILE_HDDVD_ROM           0x0050
+#define MMC_PROFILE_HDDVD_R             0x0051
+#define MMC_PROFILE_HDDVD_RAM           0x0052
+#define MMC_PROFILE_HDDVD_RW            0x0053
+#define MMC_PROFILE_HDDVD_R_DL          0x0058
+#define MMC_PROFILE_HDDVD_RW_DL         0x005A
+#define MMC_PROFILE_INVALID             0xFFFF
+
 #define ATAPI_INT_REASON_CD             0x01 /* 0 = data transfer */
 #define ATAPI_INT_REASON_IO             0x02 /* 1 = transfer to the host */
 #define ATAPI_INT_REASON_REL            0x04
@@ -540,7 +578,7 @@ static void ide_atapi_identify(IDEState 
     put_le16(p + 21, 512); /* cache size in sectors */
     put_le16(p + 22, 4); /* ecc bytes */
     padstr((char *)(p + 23), QEMU_VERSION, 8); /* firmware version */
-    padstr((char *)(p + 27), "QEMU CD-ROM", 40); /* model */
+    padstr((char *)(p + 27), "QEMU DVD-ROM", 40); /* model */
     put_le16(p + 48, 1); /* dword I/O (XXX: should not be set on CDROM) */
 #ifdef USE_DMA_CDROM
     put_le16(p + 49, 1 << 9 | 1 << 8); /* DMA and LBA supported */
@@ -1290,6 +1328,22 @@ static void ide_atapi_cmd_read(IDEState 
     }
 }
 
+static inline uint8_t ide_atapi_set_profile(uint8_t *buf, uint8_t *index,
+                                            uint16_t profile)
+{
+    uint8_t *buf_profile = buf + 12; /* start of profiles */
+
+    buf_profile += ((*index) * 4); /* start of indexed profile */
+    cpu_to_ube16 (buf_profile, profile);
+    buf_profile[2] = ((buf_profile[0] == buf[6]) && (buf_profile[1] == buf[7]));
+
+    /* each profile adds 4 bytes to the response */
+    (*index)++;
+    buf[11] += 4; /* Additional Length */
+
+    return 4;
+}
+
 static void ide_atapi_cmd(IDEState *s)
 {
     const uint8_t *packet;
@@ -1634,13 +1688,13 @@ static void ide_atapi_cmd(IDEState *s)
         buf[6] = 0; /* reserved */
         buf[7] = 0; /* reserved */
         padstr8(buf + 8, 8, "QEMU");
-        padstr8(buf + 16, 16, "QEMU CD-ROM");
+        padstr8(buf + 16, 16, "QEMU DVD-ROM");
         padstr8(buf + 32, 4, QEMU_VERSION);
         ide_atapi_cmd_reply(s, 36, max_len);
         break;
     case GPCMD_GET_CONFIGURATION:
         {
-            uint64_t total_sectors;
+            uint32_t len;
 
             /* only feature 0 is supported */
             if (packet[2] != 0 || packet[3] != 0) {
@@ -1648,17 +1702,37 @@ static void ide_atapi_cmd(IDEState *s)
                                     ASC_INV_FIELD_IN_CMD_PACKET);
                 break;
             }
-            memset(buf, 0, 32);
-            bdrv_get_geometry(s->bs, &total_sectors);
-            buf[3] = 16;
-            buf[7] = total_sectors <= 1433600 ? 0x08 : 0x10; /* current profile */
-            buf[10] = 0x10 | 0x1;
-            buf[11] = 0x08; /* size of profile list */
-            buf[13] = 0x10; /* DVD-ROM profile */
-            buf[14] = buf[7] == 0x10; /* (in)active */
-            buf[17] = 0x08; /* CD-ROM profile */
-            buf[18] = buf[7] == 0x08; /* (in)active */
-            ide_atapi_cmd_reply(s, 32, 32);
+            max_len = ube16_to_cpu(packet + 7);
+
+	    /* XXX: avoid overflow for io_buffer if max_len is too big */
+            if (max_len > 512)
+                max_len = 512;
+
+            memset(buf, 0, max_len);
+
+            /* 
+	     * the number of sectors from the media tells us which profile
+	     * to use as current.  0 means there is no media
+	     */
+            if ((s -> nb_sectors)) {
+                if ((s -> nb_sectors > CD_MAX_SECTORS))
+                    cpu_to_ube16(buf + 6, MMC_PROFILE_DVD_ROM);
+                else
+                    cpu_to_ube16(buf + 6, MMC_PROFILE_CD_ROM);
+            }
+
+            len = 8; /* header completed */
+            if (max_len > len) {
+                uint8_t index = 0;
+
+                buf[10] = 0x02 | 0x01; /* persistent and current */
+                len += 4; /* header */
+                len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_DVD_ROM);
+                len += ide_atapi_set_profile(buf, &index, MMC_PROFILE_CD_ROM);
+            }
+            cpu_to_ube32(buf, len - 4); /* data length */
+
+            ide_atapi_cmd_reply(s, len, max_len);
             break;
         }
     default: