Re: [PATCH v3 07/19] pc-bios/s390-ccw: Remove panics from ISO IPL path

[Thomas Huth <thuth@redhat.com>]

On 08/10/2024 03.15, jrossi@linux.ibm.com wrote:
> From: Jared Rossi <jrossi@linux.ibm.com>
> 
> Remove panic-on-error from IPL ISO El Torito specific functions so that error
> recovery may be possible in the future.
> 
> Functions that would previously panic now provide a return code.
> 
> Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
> ---
...
> diff --git a/pc-bios/s390-ccw/bootmap.c b/pc-bios/s390-ccw/bootmap.c
> index 414c3f1b47..7984de62fe 100644
> --- a/pc-bios/s390-ccw/bootmap.c
> +++ b/pc-bios/s390-ccw/bootmap.c
> @@ -678,8 +678,10 @@ static bool is_iso_bc_entry_compatible(IsoBcSection *s)
>       if (s->unused || !s->sector_count) {
>           return false;
>       }
> -    read_iso_sector(bswap32(s->load_rba), magic_sec,
> -                    "Failed to read image sector 0");
> +    if (virtio_read(bswap32(s->load_rba), magic_sec)) {
> +        puts("Failed to read image sector 0");
> +        return false;
> +    }
>   
>       /* Checking bytes 8 - 32 for S390 Linux magic */
>       return !memcmp(magic_sec + 8, linux_s390_magic, 24);
> @@ -699,21 +701,28 @@ static inline uint32_t iso_get_file_size(uint32_t load_rba)
>       uint8_t *temp = sec + ISO_SECTOR_SIZE;
>       int level = 0;
>   
> -    read_iso_sector(ISO_PRIMARY_VD_SECTOR, sec,
> -                    "Failed to read ISO primary descriptor");
> +    if (virtio_read(ISO_PRIMARY_VD_SECTOR, sec)) {
> +        puts("Failed to read ISO primary descriptor");
> +        return -EIO;
> +    }

iso_get_file_size() seems to return an uint32_t value, so returning a 
negative error code won't work here. I think you either have to change the 
return type to signed "long" and fix the caller site, too, or return 0 for 
errors here?

  Thomas