Re: [Qemu-devel] [PATCH 2/5][RFC] virtio-net: Add load/save for statusbits

[Dor Laor <dlaor@redhat.com>]

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Krumme, Chris wrote:
>> -----Original Message-----
>> From: 
>> qemu-devel-bounces+chris.krumme=windriver.com@nongnu.org 
>> [mailto:qemu-devel-bounces+chris.krumme=windriver.com@nongnu.o
>> rg] On Behalf Of Alex Williamson
>> Sent: Wednesday, January 07, 2009 11:38 AM
>> To: kvm; qemu-devel
>> Cc: Mark McLoughlin
>> Subject: [Qemu-devel] [PATCH 2/5][RFC] virtio-net: Add 
>> load/save for statusbits
>>
>> virtio-net: Add load/save for status bits
>>
>> Signed-off-by: Alex Williamson <alex.williamson@hp.com>
>> ---
>>
>>  hw/virtio-net.c |   10 ++++++++--
>>  1 files changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/virtio-net.c b/hw/virtio-net.c
>> index bfb7510..77e3077 100644
>> --- a/hw/virtio-net.c
>> +++ b/hw/virtio-net.c
>> @@ -16,6 +16,8 @@
>>  #include "qemu-timer.h"
>>  #include "virtio-net.h"
>>  
>> +#define VIRTIO_VM_VERSION	2
>> +
>>  typedef struct VirtIONet
>>  {
>>      VirtIODevice vdev;
>> @@ -307,13 +309,14 @@ static void virtio_net_save(QEMUFile 
>> *f, void *opaque)
>>  
>>      qemu_put_buffer(f, n->mac, 6);
>>      qemu_put_be32(f, n->tx_timer_active);
>> +    qemu_put_be16(f, n->status);
>>  }
>>  
>>  static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>>  {
>>      VirtIONet *n = opaque;
>>  
>> -    if (version_id != 1)
>> +    if (version_id < 1 || version_id > VIRTIO_VM_VERSION)
>>          return -EINVAL;
>>  
>>      virtio_load(&n->vdev, f);
>> @@ -321,6 +324,9 @@ static int virtio_net_load(QEMUFile *f, 
>> void *opaque, int version_id)
>>      qemu_get_buffer(f, n->mac, 6);
>>      n->tx_timer_active = qemu_get_be32(f);
>>  
>> +    if (version_id >= 2)
>> +        n->status = qemu_get_be16(f);
>> +
>>     
>
> Hello,
>
> I know this is a late reply, but just thought I would ask:
>
> You have the magic number 2 here, and change it to three in patch 5/5,
> should this not be VIRTIO_VM_VERSION?  Or a comment about where the
> number comes from.
>
>   
It is the version of the stated saved for virtio net device. The driver 
does not
know anything about it. The version number syncs between the source & 
destination
qemu. The numbering started with '1' and we increase it each time we 
save a new field.


> Thanks
> Chris
>
>   


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