Re: [Xen-devel] [PATCH v2 07/10] vm_event: Add vm_event_ng interface

From: Paul Durrant <Paul.Durrant@citrix.com>
To: 'Jan Beulich' <JBeulich@suse.com>
Cc: 'Petre Ovidiu PIRCALABU' <ppircalabu@bitdefender.com>,
	Stefano Stabellini <sstabellini@kernel.org>, Wei Liu <wl@xen.org>,
	Razvan Cojocaru <rcojocaru@bitdefender.com>,
	KonradRzeszutek Wilk <konrad.wilk@oracle.com>,
	Andrew Cooper <Andrew.Cooper3@citrix.com>,
	"Tim \(Xen.org\)" <tim@xen.org>,
	George Dunlap <George.Dunlap@citrix.com>,
	JulienGrall <julien.grall@arm.com>,
	Tamas K Lengyel <tamas@tklengyel.com>,
	"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	Alexandru Stefan ISAILA <aisaila@bitdefender.com>,
	Ian Jackson <Ian.Jackson@citrix.com>,
	Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH v2 07/10] vm_event: Add vm_event_ng interface
Date: Fri, 19 Jul 2019 08:26:27 +0000	[thread overview]
Message-ID: <ebe52ee6d8a9483b87f21d01c5f2c435@AMSPEX02CL03.citrite.net> (raw)
In-Reply-To: <014491cd-8ee7-26ff-5619-6c5d54c51b3c@suse.com>

> -----Original Message-----
> From: Jan Beulich <JBeulich@suse.com>
> Sent: 19 July 2019 09:22
> To: Paul Durrant <Paul.Durrant@citrix.com>
> Cc: 'Petre Ovidiu PIRCALABU' <ppircalabu@bitdefender.com>; JulienGrall <julien.grall@arm.com>;
> Alexandru Stefan ISAILA <aisaila@bitdefender.com>; Razvan Cojocaru <rcojocaru@bitdefender.com>; Andrew
> Cooper <Andrew.Cooper3@citrix.com>; George Dunlap <George.Dunlap@citrix.com>; Ian Jackson
> <Ian.Jackson@citrix.com>; Roger Pau Monne <roger.pau@citrix.com>; Stefano Stabellini
> <sstabellini@kernel.org>; xen-devel@lists.xenproject.org; KonradRzeszutek Wilk
> <konrad.wilk@oracle.com>; Tamas K Lengyel <tamas@tklengyel.com>; Tim (Xen.org) <tim@xen.org>; Wei Liu
> <wl@xen.org>
> Subject: Re: [PATCH v2 07/10] vm_event: Add vm_event_ng interface
> 
> On 19.07.2019 09:56, Paul Durrant wrote:
> >> From: Petre Ovidiu PIRCALABU <ppircalabu@bitdefender.com>
> >> Sent: 18 July 2019 14:59
> >>
> >> So, at this point the most promising solution is allocating the memory
> >> in XEN, sharing it with ID using share_xen_page_with_guest, and mapping
> >> it with xenforeignmemory_map_resource (with the flag
> >> XENMEM_rsrc_acq_caller_owned set)
> >
> > If that page is shared with the ID then XENMEM_rsrc_acq_caller_owned
> > should *not* be set. Also, that flag is an 'out' flag... the caller
> > doesn't decide who owns the resource.
> 
> I had implied that it's really MD that's meant here, but maybe I was
> wrong doing so.
> 
> > TBH I regret ever introducing the flag; it caused a lot of problems,
> > which is why it is no longer used.
> 
> It's a tools only interface - why don't we drop the flag if you now
> think it was a bad idea to introduce it?

I was indeed thinking I should find enough tuits to do that in the near future.

  Paul

> 
> Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel