From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49854) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cXqFU-0000Ye-Qz for qemu-devel@nongnu.org; Sun, 29 Jan 2017 09:14:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cXqFP-0003Fb-Pl for qemu-devel@nongnu.org; Sun, 29 Jan 2017 09:14:32 -0500 Received: from mout.web.de ([212.227.15.14]:59265) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cXqFP-0003F5-0v for qemu-devel@nongnu.org; Sun, 29 Jan 2017 09:14:27 -0500 References: <8a51513f-59d7-a361-a4ef-99679aa460fb@siemens.com> <874m0peu50.fsf@dusky.pond.sub.org> <533e0b17-4d60-a584-5680-559834013c68@web.de> <87inp05m8m.fsf@dusky.pond.sub.org> <4504afce-c62e-c54f-33a3-483f16dc4530@web.de> From: Jan Kiszka Message-ID: Date: Sun, 29 Jan 2017 15:14:06 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] Towards an ivshmem 2.0? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= Cc: Jailhouse , Markus Armbruster , qemu-devel , Wei Wang On 2017-01-29 15:00, Marc-André Lureau wrote: > Hi > > On Sun, Jan 29, 2017 at 12:44 PM Jan Kiszka > wrote: > > >> Of course, I'm careful with investing much time into expanding the > >> existing, for Jailhouse possibly sufficient design if there no real > >> interest in continuing the ivshmem support in QEMU - because of > >> vhost-pci or other reasons. But if that interest exists, it would be > >> beneficial for us to have QEMU supporting a compatible version > and using > >> the same guest drivers. Then I would start looking into concrete > patches > >> for it as well. > > > > Interest is difficult for me to gauge, not least because alternatives > > are still being worked on. > > I'm considering to suggest this as GSoC project now. > > > It's better for a student and for the community if the work get accepted > in the end. > > So, I think that could be an intersting GSoC (implementing your ivshmem > 2 proposal). However, if the qemu community isn't ready to accept a new > ivshmem, and would rather have vhost-pci based solution, I would suggest > a different project (hopefully Wei Wang can help define it and mentor): > work on a vhost-pci using dedicated shared PCI BARs (and kernel support > to avoid extra copy - if I understand the extra copy situation correctly). It's still open if vhost-pci can replace ivshmem (not to speak of being desirable for Jailhouse - I'm still studying). In that light, having both implementations available to do real comparisons is valuable IMHO. That said, we will play with open cards, explain the student the situation and let her/him decide knowingly. Jan PS: We have a mixed history /wrt actually merging student projects.