Re: [Qemu-devel] [PATCH] Fix ATAPI GET_CONFIGURATION function

[Alexander Graf]

Is there anything particularly wrong with this patch? Does it break  
any guest OSs I am not aware of?
If not, please include it as it's a pretty obvious bug.

Alex

On May 21, 2008, at 4:34 PM, Alexander Graf wrote:

> The current implementation of GET_CONFIGURATION in the ATAPI stack  
> of qemu replies a different length depending on the buffer, the data  
> should be written into.
>
> On the other hand the SCSI spec defines that length information has  
> to be consistent and independent of return buffer lengths.
>
> This patch makes the ATAPI emulation behave according to the spec  
> and fixes the Darwin DVD driver.
>
> Signed-off-by: Alexander Graf <address@hidden>
> Signed-off-by: Kevin Wolf <address@hidden>
>
>
>
> diff --git a/qemu/hw/ide.c b/qemu/hw/ide.c
> index a2a8299..6e585e1 100644
> --- a/qemu/hw/ide.c
> +++ b/qemu/hw/ide.c
> @@ -1717,6 +1717,7 @@ static void ide_atapi_cmd(IDEState *s)
>     case GPCMD_GET_CONFIGURATION:
>         {
>             uint32_t len;
> +            uint8_t index = 0;
>
>             /* only feature 0 is supported */
>             if (packet[2] != 0 || packet[3] != 0) {
> @@ -1753,14 +1754,11 @@ static void ide_atapi_cmd(IDEState *s)
>             }
>
>             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);
> -            }
> +            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);