Re: [Qemu-devel] [PATCH 1/4] s390/kvm: Handle hosts not supporting s390-virtio.

[Avi Kivity]

On 08/07/2012 05:52 PM, Cornelia Huck wrote:
> Running under a kvm host does not necessarily imply the presence of
> a page mapped above the main memory with the virtio information;
> however, the code includes a hard coded access to that page.
> 
> Instead, check for the presence of the page and exit gracefully
> before we hit an addressing exception if it does not exist.
> 
>  /*
>   * Init function for virtio
>   * devices are in a single page above top of "normal" mem
> @@ -443,6 +458,12 @@ static int __init kvm_devices_init(void)
>       }
>  
>       kvm_devices = (void *) real_memory_size;
> +     if (test_devices_support() < 0) {
> +             vmem_remove_mapping(real_memory_size, PAGE_SIZE);
> +             root_device_unregister(kvm_root);
> +             /* No error. */
> +             return 0;
> +     }
>  

Cleaner to defer root_device_register() until after the mapping has been
verified.


-- 
error compiling committee.c: too many arguments to function