Re: [Qemu-devel] [PATCH RFC v4 3/5] ide: necessary checks corrected to treat ATAPI-SCSI bridge as CDROM

[John Snow <jsnow@redhat.com>]

On 08/19/2015 08:49 AM, Alexander Bezzubikov wrote:
> hw/ide/qdev.c: 	corrected to treat bridge as CDROM
> hw/ide/core.c: 	same corrections as in qdev.c
> hw/ide/atapi.c:	skip some CDROM checks because bridge has only fake drive
> 
> Signed-off-by: Alexander Bezzubikov <abezzubikov@ispras.ru>
> ---
>  hw/ide/atapi.c |  4 +++-
>  hw/ide/core.c  | 24 ++++++++++++++----------
>  hw/ide/qdev.c  |  2 +-
>  3 files changed, 18 insertions(+), 12 deletions(-)
> 
> diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c
> index 79dd167..f6135e1 100644
> --- a/hw/ide/atapi.c
> +++ b/hw/ide/atapi.c
> @@ -1230,6 +1230,7 @@ void ide_atapi_cmd(IDEState *s)
>       * states rely on this behavior.
>       */
>      if (!(atapi_cmd_table[s->io_buffer[0]].flags & ALLOW_UA) &&
> +        s->drive_kind != IDE_BRIDGE &&
>          !s->tray_open && blk_is_inserted(s->blk) && s->cdrom_changed) {
>  
>          if (s->cdrom_changed == 1) {
> @@ -1245,7 +1246,8 @@ void ide_atapi_cmd(IDEState *s)
>  
>      /* Report a Not Ready condition if appropriate for the command */
>      if ((atapi_cmd_table[s->io_buffer[0]].flags & CHECK_READY) &&
> -        (!media_present(s) || !blk_is_inserted(s->blk)))
> +        (s->drive_kind != IDE_BRIDGE &&
> +        (!media_present(s) || !blk_is_inserted(s->blk))))
>      {
>          ide_atapi_cmd_error(s, NOT_READY, ASC_MEDIUM_NOT_PRESENT);
>          return;
> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index 50449ca..96824ab 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -348,7 +348,7 @@ static void ide_set_signature(IDEState *s)
>      /* put signature */
>      s->nsector = 1;
>      s->sector = 1;
> -    if (s->drive_kind == IDE_CD) {
> +    if (s->drive_kind == IDE_CD || s->drive_kind == IDE_BRIDGE) {
>          s->lcyl = 0x14;
>          s->hcyl = 0xeb;
>      } else if (s->blk) {
> @@ -1144,7 +1144,7 @@ static bool cmd_data_set_management(IDEState *s, uint8_t cmd)
>  
>  static bool cmd_identify(IDEState *s, uint8_t cmd)
>  {
> -    if (s->blk && s->drive_kind != IDE_CD) {
> +    if (s->blk && s->drive_kind != IDE_CD && s->drive_kind != IDE_BRIDGE) {
>          if (s->drive_kind != IDE_CFATA) {
>              ide_identify(s);
>          } else {
> @@ -1155,7 +1155,7 @@ static bool cmd_identify(IDEState *s, uint8_t cmd)
>          ide_set_irq(s->bus);
>          return false;
>      } else {
> -        if (s->drive_kind == IDE_CD) {
> +        if (s->drive_kind == IDE_CD || s->drive_kind == IDE_BRIDGE) {
>              ide_set_signature(s);
>          }
>          ide_abort_command(s);
> @@ -1232,7 +1232,7 @@ static bool cmd_read_pio(IDEState *s, uint8_t cmd)
>  {
>      bool lba48 = (cmd == WIN_READ_EXT);
>  
> -    if (s->drive_kind == IDE_CD) {
> +    if (s->drive_kind == IDE_CD || s->drive_kind == IDE_BRIDGE) {
>          ide_set_signature(s); /* odd, but ATA4 8.27.5.2 requires it */
>          ide_abort_command(s);
>          return true;
> @@ -1426,7 +1426,7 @@ static bool cmd_exec_dev_diagnostic(IDEState *s, uint8_t cmd)
>  {
>      ide_set_signature(s);
>  
> -    if (s->drive_kind == IDE_CD) {
> +    if (s->drive_kind == IDE_CD || s->drive_kind == IDE_BRIDGE) {
>          s->status = 0; /* ATAPI spec (v6) section 9.10 defines packet
>                          * devices to return a clear status register
>                          * with READY_STAT *not* set. */
> @@ -1731,7 +1731,7 @@ abort_cmd:
>  }
>  
>  #define HD_OK (1u << IDE_HD)
> -#define CD_OK (1u << IDE_CD)
> +#define CD_OK ((1u << IDE_CD) | (1u << IDE_BRIDGE))
>  #define CFA_OK (1u << IDE_CFATA)
>  #define HD_CFA_OK (HD_OK | CFA_OK)
>  #define ALL_OK (HD_OK | CD_OK | CFA_OK)
> @@ -1978,10 +1978,11 @@ void ide_cmd_write(void *opaque, uint32_t addr, uint32_t val)
>          /* high to low */
>          for(i = 0;i < 2; i++) {
>              s = &bus->ifs[i];
> -            if (s->drive_kind == IDE_CD)
> +            if (s->drive_kind == IDE_CD || s->drive_kind == IDE_BRIDGE) {
>                  s->status = 0x00; /* NOTE: READY is _not_ set */
> -            else
> +            } else {
>                  s->status = READY_STAT | SEEK_STAT;
> +            }
>              ide_set_signature(s);
>          }
>      }
> @@ -2234,7 +2235,7 @@ static void ide_resize_cb(void *opaque)
>          ide_cfata_identify_size(s);
>      } else {
>          /* IDE_CD uses a different set of callbacks entirely. */
> -        assert(s->drive_kind != IDE_CD);
> +        assert(s->drive_kind != IDE_CD && s->drive_kind != IDE_BRIDGE);
>          ide_identify_size(s);
>      }
>  }
> @@ -2274,7 +2275,7 @@ int ide_init_drive(IDEState *s, BlockBackend *blk, IDEDriveKind kind,
>      s->smart_autosave = 1;
>      s->smart_errors = 0;
>      s->smart_selftest_count = 0;
> -    if (kind == IDE_CD) {
> +    if (kind == IDE_CD || kind == IDE_BRIDGE) {
>          blk_set_dev_ops(blk, &ide_cd_block_ops, s);
>          blk_set_guest_block_size(blk, 2048);
>      } else {
> @@ -2301,6 +2302,9 @@ int ide_init_drive(IDEState *s, BlockBackend *blk, IDEDriveKind kind,
>          case IDE_CD:
>              strcpy(s->drive_model_str, "QEMU DVD-ROM");
>              break;
> +        case IDE_BRIDGE:
> +            strcpy(s->drive_model_str, "QEMU VIRTUAL ATAPI-SCSI BRIDGE");
> +            break;
>          case IDE_CFATA:
>              strcpy(s->drive_model_str, "QEMU MICRODRIVE");
>              break;
> diff --git a/hw/ide/qdev.c b/hw/ide/qdev.c
> index 3bf3401..2ed0c39 100644
> --- a/hw/ide/qdev.c
> +++ b/hw/ide/qdev.c
> @@ -182,7 +182,7 @@ static int ide_dev_initfn(IDEDevice *dev, IDEDriveKind kind)
>      }
>  
>      blkconf_serial(&dev->conf, &dev->serial);
> -    if (kind != IDE_CD) {
> +    if (kind != IDE_CD && kind != IDE_BRIDGE) {
>          blkconf_geometry(&dev->conf, &dev->chs_trans, 65536, 16, 255, &err);
>          if (err) {
>              error_report_err(err);
> 

More comments to follow pending a more rigorous look, but there are some
checks for IDE_CD in ahci.c that we should be adjusting to work with the
bridge as well.

Maybe there's a better way to handle the signature generation, relying
on the core layer here that's already managing it, which is something I
might have to do for 2.5, but in the meantime your patches should likely
update ahci.c to understand the scsi bridge as well.

Looks good at a glance otherwise, though I have some questions about the
edits made to atapi.c here that I'll save until after I read the
subsequent patches.

--js