From mboxrd@z Thu Jan 1 00:00:00 1970 From: Razvan Cojocaru Subject: Re: [PATCH] xen: Disable REP MOVSD optimization if introspection is active Date: Mon, 27 Oct 2014 15:33:44 +0200 Message-ID: <544E49B8.5030204@bitdefender.com> References: <1414406263-11421-1-git-send-email-rcojocaru@bitdefender.com> <544E2383.1020604@citrix.com> <544E27F3.2080703@bitdefender.com> <544E505302000078000426E2@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <544E505302000078000426E2@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: Andrew Cooper , keir@xen.org, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 10/27/2014 03:01 PM, Jan Beulich wrote: >>>> On 27.10.14 at 12:09, wrote: >> If you feel that the patch is acceptable, I'll correct the description >> when submitting V2. > > I think it's not unreasonable conceptually, but I somewhat doubt the > place you put the change is the right one. For one it only covers > "rep movs", but not "rep ins" or "rep outs", and then even non-rep > memory access may be broken up (due to the 8 byte limit of the > channel to qemu). For me (lacking sufficient mem-event knowledge) > it is quite hard to tell whether your change perhaps should be near > the actual generation of the mem-event (simply because I can't - > without spending more time than I have for this - right now see > where exactly that event gets generated). Perhaps > hvmemul_virtual_to_linear() should be made force *reps to 1 in > that case instead of making various functions return failure? Thank you, that's certainly a more elegant way to handle it than my hack. I'll test it with reps set to 1 in hvmemul_virtual_to_linear(), and if all goes well and there are no objections to this way of handling it, will submit a new patch. Thanks, Razvan