From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v10 0/8] xen/arm: introduce GNTTABOP_cache_flush Date: Wed, 22 Oct 2014 13:40:13 +0100 Message-ID: <5447A5AD.70608@linaro.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Stefano Stabellini , xen-devel@lists.xensource.com Cc: Julien Grall , Ian Campbell , JBeulich@suse.com List-Id: xen-devel@lists.xenproject.org Hi Stefano, On 10/21/2014 07:10 PM, Stefano Stabellini wrote: > Hi all, > this patch series introduces a new hypercall to perform cache > maintenance operations on behalf of the guest. It is useful for dom0 to > be able to cache flush pages involved in a dma operation with > non-coherent devices. > > It also removes XENFEAT_grant_map_identity as the feature is no longer > necessary: it was used to achieve the same goal but the guest can now > use the hypercall instead. Keeping the flag would also have a > significant performance impact as a new p2m mapping gets created and > then destroyed for every grant that is mapped and unmapped in dom0. I don't remembered if I asked before. Do you plan to write somewhere (wiki page, release note...) that some version of Linux (IIRC Linux 3.16 and 3.17) are broken when running as DOM0? Regards, -- Julien Grall