[PATCH] Revert "evtchn: refuse EVTCHNOP_status for Xen-bound event channels"

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

The commit makes a claim without any kind of justification.

The claim is false, and the commit broke lsevtchn in dom0.  It is also quite
obvious from XSM_TARGET that it has broken device model stubdoms too.

Whether to return information about a xen-owned evtchn is a matter of policy,
and it's not acceptable to short circuit the XSM on the matter.

This reverts commit f60ab5337f968e2f10c639ab59db7afb0fe4f7c3.

Fixes: f60ab5337f96 ("evtchn: refuse EVTCHNOP_status for Xen-bound event channels")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: George Dunlap <George.Dunlap@citrix.com>
CC: Jan Beulich <JBeulich@suse.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Julien Grall <julien@xen.org>
CC: Daniel Smith <dpsmith@apertussolutions.com>
---
 xen/common/event_channel.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 20f586cf5ecd..ae6c2f902645 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -1040,12 +1040,6 @@ int evtchn_status(evtchn_status_t *status)
 
     read_lock(&d->event_lock);
 
-    if ( consumer_is_xen(chn) )
-    {
-        rc = -EACCES;
-        goto out;
-    }
-
     rc = xsm_evtchn_status(XSM_TARGET, d, chn);
     if ( rc )
         goto out;

base-commit: 7a09966e7b2823b70f6d56d0cf66c11124f4a3c1
-- 
2.30.2