Re: [Qemu-devel] [PATCH 0/7] virtio: avoid inappropriate QEMU termination

[Gonglei <arei.gonglei@huawei.com>]

On 2016/9/21 21:13, Greg Kurz wrote:
> This series is a follow up to Stefan's work to eradicate most calls to
> exit() we currently have in the virtio code.
> 
> It addresses all exit() call sites in the blk, net and scsi device code,
> where the error is about a missing or malformed in/out header sent by
> the guest. They are converted to use virtio_error() and stop any processing,
> instead of exiting.
> 
Actually if you just stop procesing when encounter a missing in/out header but
send a interrupt to the guest, the guest maybe be stuck. virtio_net_handle_ctrl()
is an example, the guest frontend driver infinite loop to wait the interrupt's coming.
The guest can't work anymore though you don't exit the Qemu process .

Regards,
-Gonglei

> The remaining call sites are related to a host misconfiguration or a
> migration stream issue.
> 
> The 9P code currently calls assert() instead of exit(), but it also about
> malformed or missing headers, so it gets converted the same way.
> 
> Next work will be to check all assert() call sites in the device code, in
> case some of them actually refer to a bug in the guest, and should be
> converted to use virtio_error() as well.
> 
> ---
> 
> Greg Kurz (7):
>       virtio-9p: handle handle_9p_output() error
>       virtio-blk: handle virtio_blk_handle_request() errors
>       virtio-net: handle virtio_net_handle_ctrl() error
>       virtio-net: handle virtio_net_receive() errors
>       virtio-net: handle virtio_net_flush_tx() errors
>       virtio-scsi: convert virtio_scsi_bad_req() to use virtio_error()
>       virtio-scsi: handle virtio_scsi_set_config() error
> 
> 
>  hw/9pfs/virtio-9p-device.c |   14 ++++++++++--
>  hw/block/virtio-blk.c      |   27 +++++++++++++++--------
>  hw/net/virtio-net.c        |   51 +++++++++++++++++++++++++-------------------
>  hw/scsi/virtio-scsi.c      |   21 ++++++++++--------
>  4 files changed, 70 insertions(+), 43 deletions(-)
> 
> --
> Greg
> 
> 
> 
>