Re: [Xen-devel] [help] problem with `tools/xenstore/xs.c: xs_talkv()`

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Fri, 2013-01-04 at 03:55 +0000, éç wrote:

> 
>     I looked into the functions for logging, in this case,  `3 = No
> such process` was from `errno` and the ` HYPERVISOR_event_channel_op
> failed: -1 ` was from hypervisor-level
> error(src/xen/common/event_channel.c).
> In my option, that's to say, error number of -1 was caused by
> hypervisor; but what was the error number of 3 caused by,  dom0?
> Do both the two error numbers refer to the description defined in
> errno.h or else hypervisor has its own error description?

This is just the usual Unix idiom where system calls (and by extension
the ioctl used to make hypercalls) fail by returning -1 (which has no
particular meaning other than "an error occurred") and set errno to
something more specific (3 in this case, indicating ESRCH).

Please see the errno(3) man page.

Ian.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel