[Qemu-devel] [PATCH] vhost-scsi: Fix mask index err in vhost_scsi_start

[Qemu-devel] [PATCH] vhost-scsi: Fix mask index err in vhost_scsi_start

[arei.gonglei]

From: Lu Lina <lina.lulina@huawei.com>

Signed-off-by: Lu Lina <lina.lulina@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
---
 hw/scsi/vhost-scsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
index 1941aa1..174b4d2 100644
--- a/hw/scsi/vhost-scsi.c
+++ b/hw/scsi/vhost-scsi.c
@@ -117,7 +117,7 @@ static int vhost_scsi_start(VHostSCSI *s)
      * enabling/disabling irqfd.
      */
     for (i = 0; i < s->dev.nvqs; i++) {
-        vhost_virtqueue_mask(&s->dev, vdev, i, false);
+        vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
     }
 
     return ret;
-- 
1.8.5

Re: [Qemu-devel] [PATCH] vhost-scsi: Fix mask index err in vhost_scsi_start

[Paolo Bonzini]

On 27/07/2015 08:25, arei.gonglei@huawei.com wrote:
> +++ b/hw/scsi/vhost-scsi.c
> @@ -117,7 +117,7 @@ static int vhost_scsi_start(VHostSCSI *s)
>       * enabling/disabling irqfd.
>       */
>      for (i = 0; i < s->dev.nvqs; i++) {
> -        vhost_virtqueue_mask(&s->dev, vdev, i, false);
> +        vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
>      }
>  
>      return ret;

Is this fixing an actual bug, or just using the API correctly?
s->dev.vq_index is always 0, right?

Paolo

Re: [Qemu-devel] [PATCH] vhost-scsi: Fix mask index err in vhost_scsi_start

[Gonglei]

On 2015/7/27 18:20, Paolo Bonzini wrote:
> 
> 
> On 27/07/2015 08:25, arei.gonglei@huawei.com wrote:
>> +++ b/hw/scsi/vhost-scsi.c
>> @@ -117,7 +117,7 @@ static int vhost_scsi_start(VHostSCSI *s)
>>       * enabling/disabling irqfd.
>>       */
>>      for (i = 0; i < s->dev.nvqs; i++) {
>> -        vhost_virtqueue_mask(&s->dev, vdev, i, false);
>> +        vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
>>      }
>>  
>>      return ret;
> 
> Is this fixing an actual bug, or just using the API correctly?
> s->dev.vq_index is always 0, right?
> 
Yes.  At present, we found that s->dev.vq_index is always 0.

Regards,
-Gonglei

Re: [Qemu-devel] [PATCH] vhost-scsi: Fix mask index err in vhost_scsi_start

[Paolo Bonzini]

On 27/07/2015 13:11, Gonglei wrote:
> On 2015/7/27 18:20, Paolo Bonzini wrote:
>>
>>
>> On 27/07/2015 08:25, arei.gonglei@huawei.com wrote:
>>> +++ b/hw/scsi/vhost-scsi.c
>>> @@ -117,7 +117,7 @@ static int vhost_scsi_start(VHostSCSI *s)
>>>       * enabling/disabling irqfd.
>>>       */
>>>      for (i = 0; i < s->dev.nvqs; i++) {
>>> -        vhost_virtqueue_mask(&s->dev, vdev, i, false);
>>> +        vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
>>>      }
>>>  
>>>      return ret;
>>
>> Is this fixing an actual bug, or just using the API correctly?
>> s->dev.vq_index is always 0, right?
>>
> Yes.  At present, we found that s->dev.vq_index is always 0.

Ok, then I've applied the patch with this commit message:

vhost_virtqueue_mask takes an "absolute" virtqueue index, while the
code looks like it's passing an index that is relative to
s->dev.vq_index.  In reality, s->dev.vq_index is always zero, so
this patch does not make any difference, but the code is clearer.

Paolo

Re: [Qemu-devel] [PATCH] vhost-scsi: Fix mask index err in vhost_scsi_start

[Gonglei]

On 2015/7/27 19:35, Paolo Bonzini wrote:
> 
> 
> On 27/07/2015 13:11, Gonglei wrote:
>> On 2015/7/27 18:20, Paolo Bonzini wrote:
>>>
>>>
>>> On 27/07/2015 08:25, arei.gonglei@huawei.com wrote:
>>>> +++ b/hw/scsi/vhost-scsi.c
>>>> @@ -117,7 +117,7 @@ static int vhost_scsi_start(VHostSCSI *s)
>>>>       * enabling/disabling irqfd.
>>>>       */
>>>>      for (i = 0; i < s->dev.nvqs; i++) {
>>>> -        vhost_virtqueue_mask(&s->dev, vdev, i, false);
>>>> +        vhost_virtqueue_mask(&s->dev, vdev, s->dev.vq_index + i, false);
>>>>      }
>>>>  
>>>>      return ret;
>>>
>>> Is this fixing an actual bug, or just using the API correctly?
>>> s->dev.vq_index is always 0, right?
>>>
>> Yes.  At present, we found that s->dev.vq_index is always 0.
> 
> Ok, then I've applied the patch with this commit message:
> 
> vhost_virtqueue_mask takes an "absolute" virtqueue index, while the
> code looks like it's passing an index that is relative to
> s->dev.vq_index.  In reality, s->dev.vq_index is always zero, so
> this patch does not make any difference, but the code is clearer.
> 
It's better, thanks.

Regards,
-Gonglei