Re: [PATCH 4/4] kexec/xen: directly load images images into Xen

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 04/10/2013 22:33, Daniel Kiper wrote:
>
> +	xch = xc_interface_open(NULL, NULL, 0);
> +	if (!xch)
> +		return -1;
> +
> +	type = kexec_flags & KEXEC_TYPE_CRASH;
> Why? Could not we unload normal kexec images?

type is 0 for normal images and 1 for crash images.  This line does not
prevent unloading of normal images in the slightest.

>
>> +	ret = xc_kexec_unload(xch, type);
>> +
>> +	xc_interface_close(xch);
>> +
>> +	return ret;
>> +}
>> +
>> @@ -823,7 +830,10 @@ static int my_shutdown(void)
>>   */
>>  static int my_exec(void)
>>  {
>> -	reboot(LINUX_REBOOT_CMD_KEXEC);
>> +	if (xen_present())
>> +		xen_kexec_exec();
>> +	else
>> +		reboot(LINUX_REBOOT_CMD_KEXEC);
>>  	/* I have failed if I make it here */
>>  	fprintf(stderr, "kexec failed: %s\n",
>>  		strerror(errno));
>> @@ -928,6 +938,10 @@ static int kexec_loaded(void)
>>  	char *p;
>>  	char line[3];
>>
>> +	/* No way to tell if an image is loaded under Xen, assume it is. */
>> +	if (xen_present())
>> +		return 1;
>> +
> Why? I think that we should have relevant machanism to do that.
>
> Please take into account Konrad's comments too
> (http://lists.xenproject.org/archives/html/xen-devel/2013-09/msg02364.html).
>
> Daniel

Here I would agree.  As we are redefining all the hypercalls, a
KEXEC_loaded_status hypercall (or equiv) would certainly not go amis.

~Andrew