Re: [Qemu-devel] [PATCH] ide: fix ATAPI read drive structure command (v3)

[Alex Williamson]

Hi Alex,

I think I've incorporated all your comments.  I tested with sg_raw; the
embedded size value is constant regardless of the allocation length in
the command.  I added extra parameters to ide_dvd_read_structure() but I
still had to pass the IDEState pointer for things like the sector count,
and maybe others in the future as more command options are added.  I
implemented the 0xff command based on what I saw using sg_raw on real
hardware.  I'll note that it seems to be device dependent whether this
command works when the drive is empty or contains CD media.

Hopefully we're getting close, let me know if you have further comments.
Thanks,

        Alex

Fix ATAPI read drive structure command

Previous version ignored the allocation length parameter and read the
format byte from the wrong location.  Re-implement to support the full
requirements for DVD-ROM and allow for easy extension later.

Signed-off-by: Alex Williamson <address@hidden>
--

diff -r 1f1541286539 trunk/hw/ide.c
--- a/trunk/hw/ide.c    Sun May 25 15:01:05 2008 -0600
+++ b/trunk/hw/ide.c    Mon Jun 02 16:09:28 2008 -0600
@@ -351,6 +351,7 @@
 #define ASC_ILLEGAL_OPCODE                   0x20
 #define ASC_LOGICAL_BLOCK_OOR                0x21
 #define ASC_INV_FIELD_IN_CMD_PACKET          0x24
+#define ASC_INCOMPATIBLE_FORMAT              0x30
 #define ASC_MEDIUM_NOT_PRESENT               0x3a
 #define ASC_SAVING_PARAMETERS_NOT_SUPPORTED  0x39
 
@@ -433,6 +434,22 @@ typedef struct IDEState {
     uint8_t *mdata_storage;
     int media_changed;
 } IDEState;
+
+/* XXX: DVDs that could fit on a CD will be reported as a CD */
+static inline int media_present(IDEState *s)
+{
+    return (s->nb_sectors > 0);
+}
+
+static inline int media_is_dvd(IDEState *s)
+{
+    return (media_present(s) && s->nb_sectors > CD_MAX_SECTORS);
+}
+
+static inline int media_is_cd(IDEState *s)
+{
+    return (media_present(s) && s->nb_sectors <= CD_MAX_SECTORS);
+}
 
 #define BM_STATUS_DMAING 0x01
 #define BM_STATUS_ERROR  0x02
@@ -1364,6 +1381,93 @@ static inline uint8_t ide_atapi_set_prof
     return 4;
 }
 
+static int ide_dvd_read_structure(IDEState *s, int format,
+                                  const uint8_t *packet, uint8_t *buf)
+{
+    switch (format) {
+        case 0x0: /* Physical format information */
+            {
+                int layer = packet[6];
+                uint64_t total_sectors;
+
+                if (layer != 0)
+                    return -ASC_INV_FIELD_IN_CMD_PACKET;
+
+                bdrv_get_geometry(s->bs, &total_sectors);
+                total_sectors >>= 2;
+                if (total_sectors == 0)
+                    return -ASC_MEDIUM_NOT_PRESENT;
+
+                buf[4] = 1;   /* DVD-ROM, part version 1 */
+                buf[5] = 0xf; /* 120mm disc, minimum rate unspecified */
+                buf[6] = 1;   /* one layer, read-only (per MMC-2 spec) */
+                buf[7] = 0;   /* default densities */
+
+                /* FIXME: 0x30000 per spec? */
+                cpu_to_ube32(buf + 8, 0); /* start sector */
+                cpu_to_ube32(buf + 12, total_sectors - 1); /* end sector */
+                cpu_to_ube32(buf + 16, total_sectors - 1); /* l0 end sector */
+
+                /* Size of buffer, not including 2 byte size field */
+                cpu_to_be16wu((uint16_t *)buf, 2048 + 2);
+
+                /* 2k data + 4 byte header */
+                return (2048 + 4);
+            }
+
+        case 0x01: /* DVD copyright information */
+            buf[4] = 0; /* no copyright data */
+            buf[5] = 0; /* no region restrictions */
+
+            /* Size of buffer, not including 2 byte size field */
+            cpu_to_be16wu((uint16_t *)buf, 4 + 2);
+
+            /* 4 byte header + 4 byte data */
+            return (4 + 4);
+
+        case 0x03: /* BCA information - invalid field for no BCA info */
+            return -ASC_INV_FIELD_IN_CMD_PACKET;
+
+        case 0x04: /* DVD disc manufacturing information */
+            /* Size of buffer, not including 2 byte size field */
+            cpu_to_be16wu((uint16_t *)buf, 2048 + 2);
+
+            /* 2k data + 4 byte header */
+            return (2048 + 4);
+
+        case 0xff:
+            /*
+             * This lists all the command capabilities above.  Add new ones
+             * in order and update the length and buffer return values.
+             */
+
+            buf[4] = 0x00; /* Physical format */
+            buf[5] = 0x40; /* Not writable, is readable */
+            cpu_to_be16wu((uint16_t *)(buf + 6), 2048 + 4);
+
+            buf[8] = 0x01; /* Copyright info */
+            buf[9] = 0x40; /* Not writable, is readable */
+            cpu_to_be16wu((uint16_t *)(buf + 10), 4 + 4);
+
+            buf[12] = 0x03; /* BCA info */
+            buf[13] = 0x40; /* Not writable, is readable */
+            cpu_to_be16wu((uint16_t *)(buf + 14), 188 + 4);
+
+            buf[16] = 0x04; /* Manufacturing info */
+            buf[17] = 0x40; /* Not writable, is readable */
+            cpu_to_be16wu((uint16_t *)(buf + 18), 2048 + 4);
+
+            /* Size of buffer, not including 2 byte size field */
+            cpu_to_be16wu((uint16_t *)buf, 16 + 2);
+
+            /* data written + 4 byte header */
+            return (16 + 4);
+
+        default: /* TODO: formats beyond DVD-ROM requires */
+            return -ASC_INV_FIELD_IN_CMD_PACKET;
+    }
+}
+
 static void ide_atapi_cmd(IDEState *s)
 {
     const uint8_t *packet;
@@ -1651,42 +1755,42 @@ static void ide_atapi_cmd(IDEState *s)
     case GPCMD_READ_DVD_STRUCTURE:
         {
             int media = packet[1];
-            int layer = packet[6];
-            int format = packet[2];
-            uint64_t total_sectors;
+            int format = packet[7];
+            int ret;
 
-            if (media != 0 || layer != 0)
-            {
+            max_len = ube16_to_cpu(packet + 8);
+
+            if (format < 0xff && media_is_cd(s)) {
                 ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST,
-                                    ASC_INV_FIELD_IN_CMD_PACKET);
+                                    ASC_INCOMPATIBLE_FORMAT);
+                break;
             }
 
+            memset(buf, 0, max_len > IDE_DMA_BUF_SECTORS * 512 + 4 ?
+                   IDE_DMA_BUF_SECTORS * 512 + 4 : max_len);
+
             switch (format) {
-                case 0:
-                    bdrv_get_geometry(s->bs, &total_sectors);
-                    total_sectors >>= 2;
-                    if (total_sectors == 0) {
-                        ide_atapi_cmd_error(s, SENSE_NOT_READY,
-                                            ASC_MEDIUM_NOT_PRESENT);
+                case 0x00 ... 0x7f:
+                case 0xff:
+                    if (media == 0) {
+                        ret = ide_dvd_read_structure(s, format, packet, buf);
+
+                        if (ret < 0)
+                            ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST, 
-ret);
+                        else
+                            ide_atapi_cmd_reply(s, ret, max_len);
+
                         break;
                     }
+                    /* TODO: BD support, fall through for now */
 
-                    memset(buf, 0, 2052);
-
-                    buf[4] = 1;   // DVD-ROM, part version 1
-                    buf[5] = 0xf; // 120mm disc, maximum rate unspecified
-                    buf[6] = 0;   // one layer, embossed data
-                    buf[7] = 0;
-
-                    cpu_to_ube32(buf + 8, 0);
-                    cpu_to_ube32(buf + 12, total_sectors - 1);
-                    cpu_to_ube32(buf + 16, total_sectors - 1);
-
-                    cpu_to_be16wu((uint16_t *)buf, 2048 + 4);
-
-                    ide_atapi_cmd_reply(s, 2048 + 3, 2048 + 4);
-                    break;
-
+                /* Generic disk structures */
+                case 0x80: /* TODO: AACS volume identifier */
+                case 0x81: /* TODO: AACS media serial number */
+                case 0x82: /* TODO: AACS media identifier */
+                case 0x83: /* TODO: AACS media key block */
+                case 0x90: /* TODO: List of recognized format layers */
+                case 0xc0: /* TODO: Write protection status */
                 default:
                     ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST,
                                         ASC_INV_FIELD_IN_CMD_PACKET);
@@ -1739,16 +1843,12 @@ static void ide_atapi_cmd(IDEState *s)
             /* 
              * the number of sectors from the media tells us which profile
              * to use as current.  0 means there is no media
-             *
-             * XXX: fails to detect correctly DVDs with less data burned
-             *      than what a CD can hold
              */
-            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);
-            }
+            if (media_is_dvd(s))
+                cpu_to_ube16(buf + 6, MMC_PROFILE_DVD_ROM);
+            else if (media_is_cd(s))
+                cpu_to_ube16(buf + 6, MMC_PROFILE_CD_ROM);
+            
 
             len = 8; /* header completed */
             if (max_len > len) {