From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars Kurth Subject: Re: [PATCH] vm_event: Implement ARM SMC events Date: Wed, 13 Apr 2016 16:06:40 +0100 Message-ID: <0307D576-2907-4B35-BFC9-FAD67E340C07@gmail.com> References: <1460404042-31179-1-git-send-email-tamas@tklengyel.com> <570CA910.8050404@bitdefender.com> <570D2135.1040204@arm.com> <570D2AC3.2040801@bitdefender.com> <570E0967.3070600@bitdefender.com> <570E1CD5.7000802@citrix.com> <570E2513.5060502@bitdefender.com> <570E3548.3040502@citrix.com> Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\)) Content-Type: multipart/mixed; boundary="===============0728024146449044945==" Return-path: Received: from mail6.bemta6.messagelabs.com ([85.158.143.247]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1aqMNR-00078h-Ib for xen-devel@lists.xenproject.org; Wed, 13 Apr 2016 15:06:45 +0000 Received: by mail-wm0-f44.google.com with SMTP id a140so107093308wma.0 for ; Wed, 13 Apr 2016 08:06:43 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Tamas K Lengyel , Razvan Cojocaru Cc: Lars Kurth , Wei Liu , Stefano Stabellini , Andrew Cooper , Ian Jackson , Julien Grall , Jan Beulich , Xen-devel , Keir Fraser , Corneliu ZUZU List-Id: xen-devel@lists.xenproject.org --===============0728024146449044945== Content-Type: multipart/alternative; boundary="Apple-Mail=_E4132F53-2F21-46D2-880B-3309DB6EC069" --Apple-Mail=_E4132F53-2F21-46D2-880B-3309DB6EC069 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii > On 13 Apr 2016, at 14:25, Tamas K Lengyel = wrote: > In the DRAKVUF system that's exactly what I do, I mark the page = execute only so that the guest is unable to locate/overwrite injected = breakpoints without notice. If it were to overwrite injected breakpoints = with its own, then we would be able to tell that the trap is both for = external and internal use. So there isn't much of an issue there. The = main issue is with the racecondition in multi-vCPU guests when the = purely external-use breakpoint has to be removed to allow the guest to = continue. It can be solved nicely though with altp2m. I did a write-up = for the Xen blog about it a couple months ago and sent it to publicity = but has not appeared yet. Lars? >=20 Tamas, it hasn't because I was under the impression that Razvan and you = disagreed on some aspects of the article. And then I forgot to chase = either of you. I am happy with the article: feel free to upload it to = the blog (or let me know, if I should) and press the button. Apologies I think there are a couple of minor knit-picks, such as replace "In the = latest release of Xen last summer several new features have been = introduced" In "Xen 4.6 several new features have been introduced" ... = assuming 4.6 is correct I will reply to publicity Regards Lars --Apple-Mail=_E4132F53-2F21-46D2-880B-3309DB6EC069 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii
On 13 Apr 2016, at 14:25, Tamas K Lengyel <tamas.k.lengyel@gmail.com> wrote:

In the DRAKVUF system that's = exactly what I do, I mark the page execute only so that the guest is = unable to locate/overwrite injected breakpoints without notice. If it = were to overwrite injected breakpoints with its own, then we would be = able to tell that the trap is both for external and internal use. So = there isn't much of an issue there. The main issue is with the = racecondition in multi-vCPU guests when the purely external-use = breakpoint has to be removed to allow the guest to continue. It can be = solved nicely though with altp2m. I did a write-up for the Xen blog = about it a couple months ago and sent it to publicity but has not = appeared yet. Lars?

Tamas,

it hasn't because I was under the impression that = Razvan and you disagreed on some aspects of the article. And then I = forgot to chase either of you. I am happy with the article: feel free to = upload it to the blog (or let me know, if I should) and press the = button. Apologies

I think there are = a couple of minor knit-picks, such as replace "In the latest release of = Xen last summer several new features have been introduced" In "Xen 4.6 = several new features have been introduced" ... assuming 4.6 is = correct

I will reply to = publicity

Regards
Lars

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