From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40016) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fDAsq-0000GS-P1 for qemu-devel@nongnu.org; Mon, 30 Apr 2018 11:38:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fDAsm-000117-M8 for qemu-devel@nongnu.org; Mon, 30 Apr 2018 11:38:32 -0400 Date: Mon, 30 Apr 2018 16:28:26 +0100 From: Roger Pau =?utf-8?B?TW9ubsOp?= Message-ID: <20180430152826.puhl4lzvbdpdmomj@MacBook-Pro-de-Roger.local> References: <1525089699-13411-1-git-send-email-paul.durrant@citrix.com> <1525089699-13411-3-git-send-email-paul.durrant@citrix.com> <20180430151145.iyou5pisaclvvn3v@MacBook-Pro-de-Roger.local> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [Xen-devel] [PATCH 2/4] block/xen_disk: remove use of grant map/unmap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Durrant Cc: "xen-devel@lists.xenproject.org" , "qemu-block@nongnu.org" , "qemu-devel@nongnu.org" , Anthony Perard , Kevin Wolf , Stefano Stabellini , Max Reitz On Mon, Apr 30, 2018 at 04:16:52PM +0100, Paul Durrant wrote: > > -----Original Message----- > > From: Roger Pau Monne > > Sent: 30 April 2018 16:12 > > To: Paul Durrant > > Cc: xen-devel@lists.xenproject.org; qemu-block@nongnu.org; qemu- > > devel@nongnu.org; Anthony Perard ; Kevin > > Wolf ; Stefano Stabellini ; Max > > Reitz > > Subject: Re: [Xen-devel] [PATCH 2/4] block/xen_disk: remove use of grant > > map/unmap > > > > On Mon, Apr 30, 2018 at 01:01:37PM +0100, Paul Durrant wrote: > > > The grant copy operation was added to libxengnttab in Xen 4.8.0. If grant > > > copy is available then data from the guest will be copied rather than > > > mapped. > > > The xen_disk source can be significantly simplified by removing this now > > > redundant code. > > > > Hm, I know this is a PITA, but FreeBSD gntdev hasn't implemented the > > grant-copy operation yet. > > > > I could try to implement it, but I can't make any promises on the time > > ATM, since I'm quite busy. > > > > I guess we could carry a compat patch in QEMU that implements grant copy by doing a map/memcpy/unmap , but QEMU feels like the wrong place for that. I could try putting together a similar patch for the freebsd.c component of libxengnttab in the xen source rather than it simply failing with ENOSYS as it does now. Would either of those help? Maybe this could be implemented in gnttab_core.c, so it can also be used by MiniOS and Linux versions not supporting the copy ioctl as a fallback? Roger. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Pau =?utf-8?B?TW9ubsOp?= Subject: Re: [PATCH 2/4] block/xen_disk: remove use of grant map/unmap Date: Mon, 30 Apr 2018 16:28:26 +0100 Message-ID: <20180430152826.puhl4lzvbdpdmomj@MacBook-Pro-de-Roger.local> References: <1525089699-13411-1-git-send-email-paul.durrant@citrix.com> <1525089699-13411-3-git-send-email-paul.durrant@citrix.com> <20180430151145.iyou5pisaclvvn3v@MacBook-Pro-de-Roger.local> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1fDAjE-0005k6-Hh for xen-devel@lists.xenproject.org; Mon, 30 Apr 2018 15:28:36 +0000 Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" To: Paul Durrant Cc: Kevin Wolf , Stefano Stabellini , "qemu-block@nongnu.org" , "qemu-devel@nongnu.org" , Max Reitz , Anthony Perard , "xen-devel@lists.xenproject.org" List-Id: xen-devel@lists.xenproject.org T24gTW9uLCBBcHIgMzAsIDIwMTggYXQgMDQ6MTY6NTJQTSArMDEwMCwgUGF1bCBEdXJyYW50IHdy b3RlOgo+ID4gLS0tLS1PcmlnaW5hbCBNZXNzYWdlLS0tLS0KPiA+IEZyb206IFJvZ2VyIFBhdSBN b25uZQo+ID4gU2VudDogMzAgQXByaWwgMjAxOCAxNjoxMgo+ID4gVG86IFBhdWwgRHVycmFudCA8 UGF1bC5EdXJyYW50QGNpdHJpeC5jb20+Cj4gPiBDYzogeGVuLWRldmVsQGxpc3RzLnhlbnByb2pl Y3Qub3JnOyBxZW11LWJsb2NrQG5vbmdudS5vcmc7IHFlbXUtCj4gPiBkZXZlbEBub25nbnUub3Jn OyBBbnRob255IFBlcmFyZCA8YW50aG9ueS5wZXJhcmRAY2l0cml4LmNvbT47IEtldmluCj4gPiBX b2xmIDxrd29sZkByZWRoYXQuY29tPjsgU3RlZmFubyBTdGFiZWxsaW5pIDxzc3RhYmVsbGluaUBr ZXJuZWwub3JnPjsgTWF4Cj4gPiBSZWl0eiA8bXJlaXR6QHJlZGhhdC5jb20+Cj4gPiBTdWJqZWN0 OiBSZTogW1hlbi1kZXZlbF0gW1BBVENIIDIvNF0gYmxvY2sveGVuX2Rpc2s6IHJlbW92ZSB1c2Ug b2YgZ3JhbnQKPiA+IG1hcC91bm1hcAo+ID4gCj4gPiBPbiBNb24sIEFwciAzMCwgMjAxOCBhdCAw MTowMTozN1BNICswMTAwLCBQYXVsIER1cnJhbnQgd3JvdGU6Cj4gPiA+IFRoZSBncmFudCBjb3B5 IG9wZXJhdGlvbiB3YXMgYWRkZWQgdG8gbGlieGVuZ250dGFiIGluIFhlbiA0LjguMC4gSWYgZ3Jh bnQKPiA+ID4gY29weSBpcyBhdmFpbGFibGUgdGhlbiBkYXRhIGZyb20gdGhlIGd1ZXN0IHdpbGwg YmUgY29waWVkIHJhdGhlciB0aGFuCj4gPiA+IG1hcHBlZC4KPiA+ID4gVGhlIHhlbl9kaXNrIHNv dXJjZSBjYW4gYmUgc2lnbmlmaWNhbnRseSBzaW1wbGlmaWVkIGJ5IHJlbW92aW5nIHRoaXMgbm93 Cj4gPiA+IHJlZHVuZGFudCBjb2RlLgo+ID4gCj4gPiBIbSwgSSBrbm93IHRoaXMgaXMgYSBQSVRB LCBidXQgRnJlZUJTRCBnbnRkZXYgaGFzbid0IGltcGxlbWVudGVkIHRoZQo+ID4gZ3JhbnQtY29w eSBvcGVyYXRpb24geWV0Lgo+ID4gCj4gPiBJIGNvdWxkIHRyeSB0byBpbXBsZW1lbnQgaXQsIGJ1 dCBJIGNhbid0IG1ha2UgYW55IHByb21pc2VzIG9uIHRoZSB0aW1lCj4gPiBBVE0sIHNpbmNlIEkn bSBxdWl0ZSBidXN5Lgo+ID4gCj4gCj4gSSBndWVzcyB3ZSBjb3VsZCBjYXJyeSBhIGNvbXBhdCBw YXRjaCBpbiBRRU1VIHRoYXQgaW1wbGVtZW50cyBncmFudCBjb3B5IGJ5IGRvaW5nIGEgbWFwL21l bWNweS91bm1hcCAsIGJ1dCBRRU1VIGZlZWxzIGxpa2UgdGhlIHdyb25nIHBsYWNlIGZvciB0aGF0 LiBJIGNvdWxkIHRyeSBwdXR0aW5nIHRvZ2V0aGVyIGEgc2ltaWxhciBwYXRjaCBmb3IgdGhlIGZy ZWVic2QuYyBjb21wb25lbnQgb2YgbGlieGVuZ250dGFiIGluIHRoZSB4ZW4gc291cmNlIHJhdGhl ciB0aGFuIGl0IHNpbXBseSBmYWlsaW5nIHdpdGggRU5PU1lTIGFzIGl0IGRvZXMgbm93LiBXb3Vs ZCBlaXRoZXIgb2YgdGhvc2UgaGVscD8KCk1heWJlIHRoaXMgY291bGQgYmUgaW1wbGVtZW50ZWQg aW4gZ250dGFiX2NvcmUuYywgc28gaXQgY2FuIGFsc28gYmUKdXNlZCBieSBNaW5pT1MgYW5kIExp bnV4IHZlcnNpb25zIG5vdCBzdXBwb3J0aW5nIHRoZSBjb3B5IGlvY3RsIGFzIGEKZmFsbGJhY2s/ CgpSb2dlci4KCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f Clhlbi1kZXZlbCBtYWlsaW5nIGxpc3QKWGVuLWRldmVsQGxpc3RzLnhlbnByb2plY3Qub3JnCmh0 dHBzOi8vbGlzdHMueGVucHJvamVjdC5vcmcvbWFpbG1hbi9saXN0aW5mby94ZW4tZGV2ZWw=