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Date: Thu, 13 Feb 2014 07:15:54 -0800
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Subject: Re: [Qemu-devel] [PULL 1/3] s390-ccw.img: Fix sporadic reboot
 hangs: Initialize next_idx
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To: Christian Borntraeger <borntraeger@de.ibm.com>, Anthony Liguori <anthony@codemonkey.ws>, Peter Maydell <peter.maydell@linaro.org>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>, Jens Freimann <jfrei@linux.vnet.ibm.com>, Alexander Graf <agraf@suse.de>, =?ISO-8859-1?Q?Andreas_F=E4rber?= <afaerber@suse.de>, qemu-devel <qemu-devel@nongnu.org>

On 02/13/2014 01:17 AM, Christian Borntraeger wrote:
> The current code does not initialize next_idx as the qemu
> elf loader does not zero the bss section.
> Make the initialization explicit.
> 
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>  pc-bios/s390-ccw/virtio.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
> index 4d6e48f..a46914d 100644
> --- a/pc-bios/s390-ccw/virtio.c
> +++ b/pc-bios/s390-ccw/virtio.c
> @@ -124,6 +124,7 @@ static void vring_init(struct vring *vr, unsigned int num, void *p,
>      vr->used->flags = VRING_USED_F_NO_NOTIFY;
>      vr->used->idx = 0;
>      vr->used_idx = 0;
> +    vr->next_idx = 0;
>  
>      debug_print_addr("init vr", vr);
>  }
> 

FWIW, I believe that rom_reset needs to do this re-zeroing of the bss.
That seems to be the only place we don't take care for datasize != romsize.


r~