From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: Returning errno values inside of hypercall structs
 (was: Re: [PATCH for-4.7 3/4] tools/xsplice: fix mixing system)
Date: Fri, 29 Apr 2016 12:22:32 -0400
Message-ID: <20160429162232.GA28172@char.us.oracle.com>
References: <20160429161619.hy57yirgq7xzwdhd@mac>
Mime-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
Return-path: <xen-devel-bounces@lists.xen.org>
Received: from mail6.bemta14.messagelabs.com ([193.109.254.103])
 by lists.xenproject.org with esmtp (Exim 4.84_2)
 (envelope-from <konrad@char.us.oracle.com>) id 1awBBl-0003XS-IL
 for xen-devel@lists.xenproject.org; Fri, 29 Apr 2016 16:22:45 +0000
Content-Disposition: inline
In-Reply-To: <20160429161619.hy57yirgq7xzwdhd@mac>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
 <mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
 <mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Errors-To: xen-devel-bounces@lists.xen.org
Sender: "Xen-devel" <xen-devel-bounces@lists.xen.org>
To: Roger Pau Monne <roger.pau@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>, andrew.cooper3@citrix.com, Ian Jackson <ian.jackson@eu.citrix.com>, Ross Lagerwall <ross.lagerwall@citrix.com>, JBeulich@suse.com, xen-devel@lists.xenproject.org
List-Id: xen-devel@lists.xenproject.org

T24gRnJpLCBBcHIgMjksIDIwMTYgYXQgMDY6MTY6MTlQTSArMDIwMCwgUm9nZXIgUGF1IE1vbm5l
IHdyb3RlOgo+IE9uIEZyaSwgQXByIDI5LCAyMDE2IGF0IDA0OjMwOjE2UE0gKzAxMDAsIFdlaSBM
aXUgd3JvdGU6Cj4gPiBPbiBGcmksIEFwciAyOSwgMjAxNiBhdCAwNToxMjo1MVBNICswMjAwLCBS
b2dlciBQYXUgTW9ubmUgd3JvdGU6Cj4gPiA+IE9uIEZyaSwgQXByIDI5LCAyMDE2IGF0IDA0OjAy
OjMzUE0gKzAxMDAsIFdlaSBMaXUgd3JvdGU6Cj4gPiA+ID4gSSBoYXZlIGEgZ3V0IGZlZWxpbmcg
dGhhdCByZXR1cm5pbmcgWEVOXyBlcnJubyB0byB1c2Vyc3BhY2UgcHJvZ3JhbSBpcwo+ID4gPiA+
IGxheWVyaW5nIHZpb2xhdGlvbi4gVGhleSBzaG91bGQgYWx3YXlzIGJlIHRyYW5zbGF0ZWQgdG8g
T1MgbGV2ZWwgZXJybm8KPiA+ID4gPiBieSBwcml2Y21kIGRyaXZlci4KPiA+ID4gCj4gPiA+IFll
cywgdGhlIGVycm9yIHZhbHVlIHJldHVybmVkIGZyb20gdGhlIGh5cGVyY2FsbCBleGVjdXRlZCBp
cyBpbmRlZWQgCj4gPiA+IHRyYW5zbGF0ZWQgaW50byB0aGUgbmF0aXZlIE9TIGVycm9yIHNwYWNl
LiBUaGUgcHJvYmxlbSBoZXJlIGlzIHRoYXQgdGhvc2UgCj4gPiA+IGVycm9yIGNvZGVzIGFyZSBy
ZXR1cm5lZCBfaW5zaWRlXyBvZiB0aGUgc3BlY2lmaWMgaHlwZXJjYWxsIHN0cnVjdCwgd2hpY2gg
Cj4gPiA+IHNhZGx5IHByaXZjbWQgZG9lc24ndCBrbm93IGFueXRoaW5nIGFib3V0Lgo+ID4gPiAK
PiA+ID4gQW5kIG9mIGNvdXJzZSB0ZWFjaGluZyBwcml2Y21kIGFib3V0IGV2ZXJ5IHBvc3NpYmxl
IGh5cGVyY2FsbCBzdHJ1Y3QgaXMgCj4gPiA+IHNpbXBseSBpbXBvc3NpYmxlLCBzaW5jZSBzb21l
IG9mIHRoZW0gYXJlIG5vdCBzdGFibGUgKGVnOiBkb21jdGxzKQo+ID4gPiAgCj4gPiA+ID4gQXJl
bid0IEZyZWVCU0QgYW5kIE5ldEJTRCBhbHJlYWR5IGRvaW5nIHRoYXQ/Cj4gPiA+IAo+ID4gPiBB
cyBzYWlkIGFib3ZlLCB0aGlzIGlzIG9ubHkgZG9uZSBmb3IgZGlyZWN0IHJldHVybiBjb2Rlcywg
ZXZlcnl0aGluZyBpbnNpZGUgCj4gPiA+IG9mIHRoZSBzdHJ1Y3QgcGFzc2VkIHRvIHRoZSBoeXBl
cmNhbGwgaXMgcmV0dXJuZWQgYXMtaXMuCj4gPiA+IAo+ID4gPiBUaGlzIGlzIGEgY29tcGxldGUg
bWVzcywgYW5kIFRCSCwgSSBkb24ndCBoYXZlIGEgY2xldmVyIGlkZWEgYWJvdXQgaG93IHRvIAo+
ID4gPiBzb2x2ZSBpdC4KPiA+ID4gCj4gPiAKPiA+IE1lIG5laXRoZXIuIE1heWJlIGEgbmV3IHRo
cmVhZCBzaG91bGQgYmUgc3RhcnRlZCB0byBkaXNjdXNzIHRoaXMuCj4gCj4gU28gaGVyZSB3ZSBh
cmUuCj4gCj4gSW4gb3JkZXIgdG8gcHV0IGV2ZXJ5b25lIGludG8gY29udGV4dDogdGhlIGlzc3Vl
IGhlcmUgaXMgdGhhdCBzb21lIAo+IGh5cGVyY2FsbHMgKHRob3NlIHRoYXQgYmF0Y2ggc2V2ZXJh
bCBvcGVyYXRpb25zKSByZXR1cm4gYW4gYXJyYXkgb2YgZXJyb3IgCj4gY29kZXMgaW5zaWRlIG9m
IHRoZSBoeXBlcmNhbGwgc3RydWN0dXJlLiBUaGlzIGFycmF5IG9mIGVycm9yIGNvZGVzIGlzIG5v
dCAKPiBzdGFuZGFyZGl6ZWQsIHNvIHRoZSBwcml2Y21kIGRyaXZlciBkb2Vzbid0IGtub3cgYW55
dGhpbmcgYWJvdXQgaXQsIGFuZCB0aHVzIAo+IGNhbm5vdCB0cmFuc2xhdGUgaXQgaW50byB0aGUg
bmF0aXZlIE9TIGVycm9yIHNwYWNlLgo+IAo+IEl0IGhhcyBhbHNvIGJlZW4gc3VnZ2VzdGVkIHRo
YXQgdGhlIHByaXZjbWQgZHJpdmVyIHNpbXBseSBkb2Vzbid0IHRyYW5zbGF0ZSAKPiBlcnJvciBj
b2RlcyBhdCBhbGwsIGFuZCB0aGVuIGxldCB0aGUgYXBwbGljYXRpb25zIGZpZ3VyZSBvdXQgaWYg
dGhlIGVycm9yIAo+IGNvZGUgY29tZXMgZnJvbSBYZW4gb3IgZnJvbSB0aGUgT1MuIElNSE8sIHRo
aXMgaXMgaW1wb3NzaWJsZSB0byBhY2hpZXZlLCAKPiBiZWNhdXNlIHRoZSBpb2N0bCBzeXNjYWxs
IGNhbiByZXR1cm4gYW4gZXJyb3IgY29kZSB0aGF0J3MgYmVlbiBmb3J3YXJkZWQgCj4gYnkgWGVu
IG9yIGEgbmF0aXZlIG9uZSwgYW5kIHRoZSBhcHBsaWNhdGlvbiBoYXMgbm8gd2F5IG9mIGtub3dp
bmcgd2hlcmUgaXMgCj4gaXQgY29taW5nIGZyb20uCj4gCj4gSSd2ZSBpZGVudGlmaWVkIGF0IGxl
YXN0IHRoZSBmb2xsb3dpbmcgaHlwZXJjYWxsIHN0cnVjdHMgdGhhdCBzdG9yZSBYRU5fKiAKPiBl
cnJvciBjb2RlcyBpbnNpZGU6Cj4gCj4gIC0geGVuX2FkZF90b19waHlzbWFwX2JhdGNoCj4gIC0g
eGVuX3hzcGxpY2Vfc3RhdHVzCj4gCj4gVEJILCBpdCdzIHF1aXRlIGhhcmQgdG8gc3BvdCB0aGVt
LCBzbyBJIG1pZ2h0IGhhdmUgbWlzc2VkIHNvbWUuIAo+IAo+IHhlbl9hZGRfdG9fcGh5c21hcF9i
YXRjaCBpcyBwYXJ0IG9mIHRoZSBwdWJsaWMgQUJJLCBhbmQgY2Fubm90IGJlIGNoYW5nZWQuIAo+
IE9uIHRoZSBicmlnaHQgc2lkZSwgeGVuX2FkZF90b19waHlzbWFwX2JhdGNoIGlzIGltcGxlbWVu
dGVkIGFzIGEgZGlmZmVyZW50IAo+IGlvY3RsIGluIHByaXZjbWQgdXN1YWxseSAoaW4gb3JkZXIg
dG8gbWFwIG1lbW9yeSBmcm9tIG90aGVyIGRvbWFpbnMpLCBzbyB0aGUgCj4gZXJyb3IgdHJhbnNs
YXRpb24gc2hvdWxkIGJlIGhhbmRsZWQgY29ycmVjdGx5Lgo+IAo+IFRoZW4gdGhlIHhzcGxpY2Ug
c3RydWN0IHRoYXQgdXNlcyBYRU5fKiB2YWx1ZXMgaXM6Cj4gCj4gc3RydWN0IHhlbl94c3BsaWNl
X3N0YXR1cyB7Cj4gI2RlZmluZSBYU1BMSUNFX1NUQVRFX0NIRUNLRUQgICAgICAxCj4gI2RlZmlu
ZSBYU1BMSUNFX1NUQVRFX0FQUExJRUQgICAgICAyCj4gICAgIHVpbnQzMl90IHN0YXRlOyAgICAg
ICAgICAgICAgICAvKiBPVVQ6IFhTUExJQ0VfU1RBVEVfKi4gKi8KPiAgICAgaW50MzJfdCByYzsg
ICAgICAgICAgICAgICAgICAgIC8qIE9VVDogMCBpZiBubyBlcnJvciwgb3RoZXJ3aXNlIC1YRU5f
RVhYLiAqLwo+IH07Cj4gCj4gV2hpY2ggaXMgaW4gdHVybiB1c2VkIGJ5Ogo+IAo+IHN0cnVjdCB4
ZW5fc3lzY3RsX3hzcGxpY2VfbGlzdCB7Cj4gICAgIHVpbnQzMl90IHZlcnNpb247ICAgICAgICAg
ICAgICAgICAgICAgICAvKiBPVVQ6IEh5cGVydmlzb3Igc3RhbXBzIHZhbHVlLgo+ICAgICAgICAg
ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgSWYgdmFyaWVzIGJldHdlZW4g
Y2FsbHMsIHdlIGFyZQo+ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg
ICAgICogZ2V0dGluZyBzdGFsZSBkYXRhLiAqLwo+ICAgICB1aW50MzJfdCBpZHg7ICAgICAgICAg
ICAgICAgICAgICAgICAgICAgLyogSU46IEluZGV4IGludG8gaHlwZXJ2aXNvciBsaXN0LiAqLwo+
ICAgICB1aW50MzJfdCBucjsgICAgICAgICAgICAgICAgICAgICAgICAgICAgLyogSU46IEhvdyBt
YW55IHN0YXR1cywgbmFtZSwgYW5kIGxlbgo+ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg
ICAgICAgICAgICAgICAgICAgc2hvdWxkIGZpbGwgb3V0LiBDYW4gYmUgemVybyB0byBnZXQKPiAg
ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIGFtb3VudCBvZiBw
YXlsb2FkcyBhbmQgdmVyc2lvbi4KPiAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg
ICAgICAgICAgICAgIE9VVDogSG93IG1hbnkgcGF5bG9hZHMgbGVmdC4gKi8KPiAgICAgdWludDMy
X3QgcGFkOyAgICAgICAgICAgICAgICAgICAgICAgICAgIC8qIElOOiBNdXN0IGJlIHplcm8uICov
Cj4gICAgIFhFTl9HVUVTVF9IQU5ETEVfNjQoeGVuX3hzcGxpY2Vfc3RhdHVzX3QpIHN0YXR1czsg
IC8qIE9VVC4gTXVzdCBoYXZlIGVub3VnaAo+ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg
ICAgICAgICAgICAgICAgICAgc3BhY2UgYWxsb2NhdGUgZm9yIG5yIG9mIHRoZW0uICovCj4gICAg
IFhFTl9HVUVTVF9IQU5ETEVfNjQoY2hhcikgbmFtZTsgICAgICAgICAvKiBPVVQ6IEFycmF5IG9m
IG5hbWVzLiBFYWNoIG1lbWJlcgo+ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg
ICAgICAgICAgICAgTVVTVCBYRU5fWFNQTElDRV9OQU1FX1NJWkUgaW4gc2l6ZS4KPiAgICAgICAg
ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIE11c3QgaGF2ZSBuciBvZiB0
aGVtLiAqLwo+ICAgICBYRU5fR1VFU1RfSEFORExFXzY0KHVpbnQzMikgbGVuOyAgICAgICAgLyog
T1VUOiBBcnJheSBvZiBsZW5ndGhzIG9mIG5hbWUncy4KPiAgICAgICAgICAgICAgICAgICAgICAg
ICAgICAgICAgICAgICAgICAgICAgICAgIE11c3QgaGF2ZSBuciBvZiB0aGVtLiAqLwo+IH07Cj4g
Cj4gSU1ITywgdGhlIGJlc3Qgd2F5IHRvIHNvbHZlIHRoaXMgaXMgdG8gZGVmaW5lIGEgc2V0IG9m
IFhTUExJQ0VfRVJST1JfKiB0aGF0IAo+IGNvdmVycyB0aGUgZXJyb3IgY29kZXMgcmV0dXJuZWQg
YnkgeHNwbGljZSwgYW5kIHVzZSB0aGF0IGluc3RlYWQgb2YgWEVOXyogCj4gZXJybm8gdmFsdWVz
LiBUaGlzIHdvdWxkIG1ha2UgaXQgbXVjaCBtb3JlIGVhc2llciB0byBhdm9pZCBtaXN0YWtlcyB3
aGVuIAo+IGNvZGluZyB0aGUgdG9vbHN0YWNrIHBhcnQgb2YgeHNwbGljZS4KCkJ1dCB3aHk/CgpJ
IG11c3QgYmUgbWlzc2luZyBzb21ldGhpbmcgaGVyZSAtIGJ1dCB0aGUgcmV0dXJuIGZyb20gdGhl
IGh5cGVyY2FsbApjYW4gcmV0dXJuIHNheSAwIGJ1dCB0aGUgc3RhdHVzLT5yYyBjYW4gYmUgLVhF
Tl9FQUdBSU4uCgpXaHkgZG9lcyBpdCBuZWVkIHRvIGJlIFhTUExJQ0VfRVJST1JfPwoKPiAKPiBS
b2dlci4KCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClhl
bi1kZXZlbCBtYWlsaW5nIGxpc3QKWGVuLWRldmVsQGxpc3RzLnhlbi5vcmcKaHR0cDovL2xpc3Rz
Lnhlbi5vcmcveGVuLWRldmVsCg==