From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suravee Suthikulpanit Subject: Re: [PATCH] x86/ats: Disable Address Translation Services by default Date: Thu, 28 Aug 2014 03:18:03 -0500 Message-ID: <53FEE5BB.7000907@amd.com> References: <1408550481-31464-1-git-send-email-andrew.cooper3@citrix.com> <53F7563C020000780002CB46@mail.emea.novell.com> <53FED55B.5030109@amd.com> <53FEF731020000780002E7A9@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <53FEF731020000780002E7A9@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: Yang Z Zhang , Andrew Cooper , Kevin Tian , Aravind Gopalakrishnan , Xen-devel List-Id: xen-devel@lists.xenproject.org On 08/28/2014 02:32 AM, Jan Beulich wrote: >>>> On 28.08.14 at 09:08, wrote: >> I have verified that PCI device pass-through works with ATS disabled. >> Although, could you please help described how "asynchronous queued >> invalidation support" supposed to work? > > Are asking about the abstract model, or the specific implementation? > The former is quite obvious is think (utilize the respective interrupt to > get notified of completions and suspend the execution in the current > context until then), So, what Andrew is saying is that the current implementation which uses the "synchronous wait for completion" is not safe? May be I'm not getting the whole picture here of how it is unsafe. Thanks, Suravee