Re: [Qemu-devel] [PATCH v5 06/10] hw/vfio: create common module

[Joel Schopp]

On 08/20/2014 02:41 PM, Alex Williamson wrote:
> On Wed, 2014-08-20 at 14:12 -0500, Joel Schopp wrote:
>>> +int vfio_get_device(VFIOGroup *group, const char *name,
>>> +                       VFIODevice *vbasedev)
>>> +{
>>> +    struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
>>> +    struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
>>> +    struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
>>> +    int ret;
>>> +
>>> +    ret = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
>>> +    if (ret < 0) {
>> Should be:
>> if(ret) {
>> instead of:
>> if (ret < 0) {
>>
>> The ioctl can, and sometimes does, return positive values in case of
>> errors.  This should also be fixed in vfio_container_do_ioctl()
> This particular ioctl usually does return a positive value, the file
> descriptor for the the device, so I think it's correct as written.
> Thanks,
Thanks for the catch, I stand corrected.  The kernel I am running
against contains corresponding patches that are spitting out an
erroneous pr_err() on if(ret).  In retrospect it looks like the kernel
patches and not the qemu patches are in the wrong.