Re: [Qemu-devel] [PATCH] SCSI passthrough: DVD support

[Fabrice Bellard]

Can you explain why you use the block layer (block-raw-posix.c) to send
your low level SCSI commands ? I suggest to remove your patches to
block-raw-posix.c and to implement all the SCSI passthough in
scsi-generic.c.

Regards,

Fabrice.

Laurent Vivier wrote:
> This patch allows to use SCSI passthrough to read movies from DVD.
> It has been tested with PowerDVD and XP.
> 
> It also introduces some comments in block-raw-posix.c to explain behavior of
> negative offset and negative nb_sectors.
> It restores original value of aio_num and aio_threads.
> 
> Laurent
> ---
>  block-raw-posix.c |    7 +++++--
>  hw/scsi-generic.c |   14 ++++++++++++--
>  2 files changed, 17 insertions(+), 4 deletions(-)
> 
> Index: qemu/hw/scsi-generic.c
> ===================================================================
> --- qemu.orig/hw/scsi-generic.c       2008-01-06 18:43:44.000000000 +0100
> +++ qemu/hw/scsi-generic.c    2008-01-06 18:55:46.000000000 +0100
> @@ -44,9 +44,12 @@ do { fprintf(stderr, "scsi-generic: " fm
>  #include <scsi/sg.h>
>  #include <scsi/scsi.h>
>  
> +#define BLANK 0xa1
> +#define SEND_KEY 0xa3
> +#define REPORT_KEY 0xa4
>  #define LOAD_UNLOAD 0xa6
> +#define READ_DVD_STRUCTURE 0xad
>  #define SET_CD_SPEED 0xbb
> -#define BLANK 0xa1
>  
>  #define SCSI_CMD_BUF_SIZE     16
>  #define SCSI_SENSE_BUF_SIZE 32
> @@ -166,7 +169,7 @@ static void scsi_command_complete(void *
>              sense = s->sensebuf[2] & 0x0f;
>      }
>  
> -    DPRINTF("Command complete 0x%p tag=0x%x sense=%d\n", r, r->tag, sense);
> +    DPRINTF("Command complete %p tag=0x%x sense=%d\n", r, r->tag, sense);
>      tag = r->tag;
>      scsi_remove_request(r);
>      s->completion(s->opaque, SCSI_REASON_DONE, tag, sense);
> @@ -427,6 +430,12 @@ static int scsi_length(uint8_t *cmd, int
>      case READ_12:
>          *len *= blocksize;
>          break;
> +  case READ_DVD_STRUCTURE:
> +  case SEND_KEY:
> +  case REPORT_KEY:
> +      *len &= 0xffff;
> +      break;
> +
>      }
>      return 0;
>  }
> @@ -464,6 +473,7 @@ static int is_write(int command)
>      case MEDIUM_SCAN:
>      case SEND_VOLUME_TAG:
>      case WRITE_LONG_2:
> +    case SEND_KEY:
>          return 1;
>      }
>      return 0;
> Index: qemu/block-raw-posix.c
> ===================================================================
> --- qemu.orig/block-raw-posix.c       2008-01-06 18:43:44.000000000 +0100
> +++ qemu/block-raw-posix.c    2008-01-06 18:45:38.000000000 +0100
> @@ -151,6 +151,8 @@ static int raw_pread(BlockDriverState *b
>      if (ret < 0)
>          return ret;
>  
> +    /* if offset < 0, we don't make lseek() */
> +
>      if (offset >= 0 && lseek(s->fd, offset, SEEK_SET) == (off_t)-1) {
>          ++(s->lseek_err_cnt);
>          if(s->lseek_err_cnt <= 10) {
> @@ -276,8 +278,8 @@ void qemu_aio_init(void)
>             seems to fix the problem. */
>          struct aioinit ai;
>          memset(&ai, 0, sizeof(ai));
> -        ai.aio_threads = 16;
> -        ai.aio_num = 16;
> +        ai.aio_threads = 1;
> +        ai.aio_num = 1;
>          ai.aio_idle_time = 365 * 100000;
>          aio_init(&ai);
>      }
> @@ -387,6 +389,7 @@ static RawAIOCB *raw_aio_setup(BlockDriv
>      acb->aiocb.aio_sigevent.sigev_signo = aio_sig_num;
>      acb->aiocb.aio_sigevent.sigev_notify = SIGEV_SIGNAL;
>      acb->aiocb.aio_buf = buf;
> +    /* if nb_sectors < 0, -nb_sectors is a number of bytes */
>      if (nb_sectors < 0)
>          acb->aiocb.aio_nbytes = -nb_sectors;
>      else
> 
> 
> 
>