ide.c

xen虚拟机源代码安装包

    s->lba = -1; /* no sector read */
    s->packet_transfer_size = size;
    s->io_buffer_size = size;    /* dma: send the reply data as one chunk */
    s->elementary_transfer_size = 0;
    s->io_buffer_index = 0;

    if (s->atapi_dma) {
    	s->status = READY_STAT | DRQ_STAT;
	ide_dma_start(s, ide_atapi_cmd_read_dma_cb);
    } else {
    	s->status = READY_STAT;
    	ide_atapi_cmd_reply_end(s);
    }
}

/* start a CD-CDROM read command */
static void ide_atapi_cmd_read_pio(IDEState *s, int lba, int nb_sectors,
                                   int sector_size)
{
    s->lba = lba;
    s->packet_transfer_size = nb_sectors * sector_size;
    s->elementary_transfer_size = 0;
    s->io_buffer_index = sector_size;
    s->cd_sector_size = sector_size;

    s->status = READY_STAT;
    ide_atapi_cmd_reply_end(s);
}

/* ATAPI DMA support */

/* XXX: handle read errors */
static void ide_atapi_cmd_read_dma_cb(void *opaque, int ret)
{
    BMDMAState *bm = opaque;
    IDEState *s = bm->ide_if;
    int data_offset, n;

    if (!s->bs) return; /* yikes */

    if (ret < 0) {
        ide_atapi_io_error(s, ret);
        goto eot;
    }

    if (s->io_buffer_size > 0) {
	/*
	 * For a cdrom read sector command (s->lba != -1),
	 * adjust the lba for the next s->io_buffer_size chunk
	 * and dma the current chunk.
	 * For a command != read (s->lba == -1), just transfer
	 * the reply data.
	 */
	if (s->lba != -1) {
	    if (s->cd_sector_size == 2352) {
		n = 1;
		cd_data_to_raw(s->io_buffer, s->lba);
	    } else {
		n = s->io_buffer_size >> 11;
	    }
	    s->lba += n;
	}
        s->packet_transfer_size -= s->io_buffer_size;
        if (dma_buf_rw(bm, 1) == 0)
            goto eot;
    }

    if (s->packet_transfer_size <= 0) {
        s->status = READY_STAT;
        s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;
        ide_set_irq(s);
    eot:
        bm->status &= ~BM_STATUS_DMAING;
        bm->status |= BM_STATUS_INT;
        bm->dma_cb = NULL;
        bm->ide_if = NULL;
        bm->aiocb = NULL;
        return;
    }
    
    s->io_buffer_index = 0;
    if (s->cd_sector_size == 2352) {
        n = 1;
        s->io_buffer_size = s->cd_sector_size;
        data_offset = 16;
    } else {
        n = s->packet_transfer_size >> 11;
        if (n > (IDE_DMA_BUF_SIZE / 2048))
            n = (IDE_DMA_BUF_SIZE / 2048);
        s->io_buffer_size = n * 2048;
        data_offset = 0;
    }
#ifdef DEBUG_AIO
    printf("aio_read_cd: lba=%u n=%d\n", s->lba, n);
#endif
    bm->aiocb = bdrv_aio_read(s->bs, (int64_t)s->lba << 2, 
                              s->io_buffer + data_offset, n * 4, 
                              ide_atapi_cmd_read_dma_cb, bm);
    if (!bm->aiocb) {
        /* Note: media not present is the most likely case */
        ide_atapi_cmd_error(s, SENSE_NOT_READY, 
                            ASC_MEDIUM_NOT_PRESENT);
        goto eot;
    }
}

/* start a CD-CDROM read command with DMA */
/* XXX: test if DMA is available */
static void ide_atapi_cmd_read_dma(IDEState *s, int lba, int nb_sectors,
                                   int sector_size)
{
    s->lba = lba;
    s->packet_transfer_size = nb_sectors * sector_size;
    s->io_buffer_index = 0;
    s->io_buffer_size = 0;
    s->cd_sector_size = sector_size;

    /* XXX: check if BUSY_STAT should be set */
    s->status = READY_STAT | DRQ_STAT | BUSY_STAT;
    ide_dma_start(s, ide_atapi_cmd_read_dma_cb);
}

static void ide_atapi_cmd_read(IDEState *s, int lba, int nb_sectors, 
                               int sector_size)
{
#ifdef DEBUG_IDE_ATAPI
    printf("read %s: LBA=%d nb_sectors=%d\n", s->atapi_dma ? "dma" : "pio",
	lba, nb_sectors);
#endif
    if (s->atapi_dma) {
        ide_atapi_cmd_read_dma(s, lba, nb_sectors, sector_size);
    } else {
        ide_atapi_cmd_read_pio(s, lba, nb_sectors, sector_size);
    }
}

static void ide_atapi_cmd(IDEState *s)
{
    const uint8_t *packet;
    uint8_t *buf;
    int max_len;

    packet = s->io_buffer;
    buf = s->io_buffer;
#ifdef DEBUG_IDE_ATAPI
    {
        int i;
        printf("ATAPI limit=0x%x packet:", s->lcyl | (s->hcyl << 8));
        for(i = 0; i < ATAPI_PACKET_SIZE; i++) {
            printf(" %02x", packet[i]);
        }
        printf("\n");
    }
#endif
    switch(s->io_buffer[0]) {
    case GPCMD_TEST_UNIT_READY:
        if (bdrv_is_inserted(s->bs)) {
            if (s->is_cdrom && s->sense_key == SENSE_NOT_READY) {
                ide_atapi_cmd_error(s, SENSE_UNIT_ATTENTION, 
                                    ASC_MEDIUM_MAY_HAVE_CHANGED);
                break;
            }
            ide_atapi_cmd_ok(s);
        } else {
            ide_atapi_cmd_error(s, SENSE_NOT_READY, 
                                ASC_MEDIUM_NOT_PRESENT);
            xenstore_check_new_media_present(1000);
        }
        break;
    case GPCMD_MODE_SENSE_10:
        {
            int action, code;
            max_len = ube16_to_cpu(packet + 7);
            action = packet[2] >> 6;
            code = packet[2] & 0x3f;
            switch(action) {
            case 0: /* current values */
                switch(code) {
                case 0x01: /* error recovery */
                    cpu_to_ube16(&buf[0], 16 + 6);
                    buf[2] = 0x70;
                    buf[3] = 0;
                    buf[4] = 0;
                    buf[5] = 0;
                    buf[6] = 0;
                    buf[7] = 0;

                    buf[8] = 0x01;
                    buf[9] = 0x06;
                    buf[10] = 0x00;
                    buf[11] = 0x05;
                    buf[12] = 0x00;
                    buf[13] = 0x00;
                    buf[14] = 0x00;
                    buf[15] = 0x00;
                    ide_atapi_cmd_reply(s, 16, max_len);
                    break;
                case 0x2a:
                    cpu_to_ube16(&buf[0], 28 + 6);
                    buf[2] = 0x70;
                    buf[3] = 0;
                    buf[4] = 0;
                    buf[5] = 0;
                    buf[6] = 0;
                    buf[7] = 0;

                    buf[8] = 0x2a;
                    buf[9] = 0x12;
                    buf[10] = 0x00;
                    buf[11] = 0x00;
                    
                    buf[12] = 0x70;
                    buf[13] = 3 << 5;
                    buf[14] = (1 << 0) | (1 << 3) | (1 << 5);
                    if (bdrv_is_locked(s->bs))
                        buf[6] |= 1 << 1;
                    buf[15] = 0x00;
                    cpu_to_ube16(&buf[16], 706);
                    buf[18] = 0;
                    buf[19] = 2;
                    cpu_to_ube16(&buf[20], 512);
                    cpu_to_ube16(&buf[22], 706);
                    buf[24] = 0;
                    buf[25] = 0;
                    buf[26] = 0;
                    buf[27] = 0;
                    ide_atapi_cmd_reply(s, 28, max_len);
                    break;
                default:
                    goto error_cmd;
                }
                break;
            case 1: /* changeable values */
                goto error_cmd;
            case 2: /* default values */
                goto error_cmd;
            default:
            case 3: /* saved values */
                ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST, 
                                    ASC_SAVING_PARAMETERS_NOT_SUPPORTED);
                break;
            }
        }
        break;
    case GPCMD_REQUEST_SENSE:
        max_len = packet[4];
        memset(buf, 0, 18);
        buf[0] = 0x70 | (1 << 7);
        buf[2] = s->sense_key;
        buf[7] = 10;
        buf[12] = s->asc;
        ide_atapi_cmd_reply(s, 18, max_len);
        break;
    case GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL:
        if (bdrv_is_inserted(s->bs)) {
            bdrv_set_locked(s->bs, packet[4] & 1);
            ide_atapi_cmd_ok(s);
        } else {
            ide_atapi_cmd_error(s, SENSE_NOT_READY, 
                                ASC_MEDIUM_NOT_PRESENT);
        }
        break;
    case GPCMD_READ_10:
    case GPCMD_READ_12:
        {
            int nb_sectors, lba;

            if (packet[0] == GPCMD_READ_10)
                nb_sectors = ube16_to_cpu(packet + 7);
            else
                nb_sectors = ube32_to_cpu(packet + 6);
            lba = ube32_to_cpu(packet + 2);
            if (nb_sectors == 0) {
                ide_atapi_cmd_ok(s);
                break;
            }
            ide_atapi_cmd_read(s, lba, nb_sectors, 2048);
        }
        break;
    case GPCMD_READ_CD:
        {
            int nb_sectors, lba, transfer_request;

            nb_sectors = (packet[6] << 16) | (packet[7] << 8) | packet[8];
            lba = ube32_to_cpu(packet + 2);
            if (nb_sectors == 0) {
                ide_atapi_cmd_ok(s);
                break;
            }
            transfer_request = packet[9];
            switch(transfer_request & 0xf8) {
            case 0x00:
                /* nothing */
                ide_atapi_cmd_ok(s);
                break;
            case 0x10:
                /* normal read */
                ide_atapi_cmd_read(s, lba, nb_sectors, 2048);
                break;
            case 0xf8:
                /* read all data */
                ide_atapi_cmd_read(s, lba, nb_sectors, 2352);
                break;
            default:
                ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST, 
                                    ASC_INV_FIELD_IN_CMD_PACKET);
                break;
            }
        }
        break;
    case GPCMD_SEEK:
        {
            int lba;
            int64_t total_sectors;

            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);
                break;
            }
            lba = ube32_to_cpu(packet + 2);
            if (lba >= total_sectors) {
                ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST, 
                                    ASC_LOGICAL_BLOCK_OOR);
                break;
            }
            ide_atapi_cmd_ok(s);
        }
        break;
    case GPCMD_START_STOP_UNIT:
        {
            int start, eject;
            start = packet[4] & 1;
            eject = (packet[4] >> 1) & 1;
            
            if (eject && !start) {
                /* eject the disk */
                bdrv_eject(s->bs, 1);
            } else if (eject && start) {
                /* close the tray */
                bdrv_eject(s->bs, 0);
            }
            ide_atapi_cmd_ok(s);
        }
        break;
    case GPCMD_MECHANISM_STATUS:
        {
            max_len = ube16_to_cpu(packet + 8);
            cpu_to_ube16(buf, 0);
            /* no current LBA */
            buf[2] = 0;
            buf[3] = 0;
            buf[4] = 0;
            buf[5] = 1;
            cpu_to_ube16(buf + 6, 0);
            ide_atapi_cmd_reply(s, 8, max_len);
        }
        break;
    case GPCMD_READ_TOC_PMA_ATIP:
        {
            int format, msf, start_track, len;
            int64_t total_sectors;

            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);
                break;
            }
            max_len = ube16_to_cpu(packet + 7);
            format = packet[9] >> 6;
            msf = (packet[1] >> 1) & 1;
            start_track = packet[6];
            switch(format) {
            case 0:
                len = cdrom_read_toc(total_sectors, buf, msf, start_track);
                if (len < 0)
                    goto error_cmd;
                ide_atapi_cmd_reply(s, len, max_len);
                break;
            case 1:
                /* multi session : only a single session defined */
                memset(buf, 0, 12);
                buf[1] = 0x0a;
                buf[2] = 0x01;
                buf[3] = 0x01;
                ide_atapi_cmd_reply(s, 12, max_len);
                break;
            case 2:
                len = cdrom_read_toc_raw(total_sectors, buf, msf, start_track);
                if (len < 0)
                    goto error_cmd;
                ide_atapi_cmd_reply(s, len, max_len);
                break;
            default:
            error_cmd:
                ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST, 
                                    ASC_INV_FIELD_IN_CMD_PACKET);
                break;
            }
        }
        break;
    case GPCMD_READ_CDVD_CAPACITY:
        {
            int64_t total_sectors;

            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);
                break;
            }
            /* NOTE: it is really the number of sectors minus 1 */
            cpu_to_ube32(buf, total_sectors - 1);
            cpu_to_ube32(buf + 4, 2048);
            ide_atapi_cmd_reply(s, 8, 8);
        }
        break;
    case GPCMD_INQUIRY:
        max_len = packet[4];
        buf[0] = 0x05; /* CD-ROM */
        buf[1] = 0x80; /* removable */
        buf[2] = 0x00; /* ISO */
        buf[3] = 0x21; /* ATAPI-2 (XXX: put ATAPI-4 ?) */
        buf[4] = 31; /* additionnal length */
        buf[5] = 0; /* reserved */
        buf[6] = 0; /* reserved */
        buf[7] = 0; /* reserved */
        padstr8(buf + 8, 8, "QEMU");
        padstr8(buf + 16, 16, "QEMU CD-ROM");