From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Biedermann Subject: Re: Logging Access to HDD Date: Tue, 19 Apr 2011 14:52:42 +0200 Message-ID: <4DAD859A.5010006@seceng.informatik.tu-darmstadt.de> References: <4DAD5296.70204@seceng.informatik.tu-darmstadt.de> <4DAD5968.1030408@seceng.informatik.tu-darmstadt.de> <4DAD5BD6.7090809@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <4DAD5BD6.7090809@redhat.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Michal Novotny Cc: James Harper , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Am 19.04.2011 11:54, schrieb Michal Novotny: > On 04/19/2011 11:44 AM, Sebastian Biedermann wrote: >> Am 19.04.2011 11:35, schrieb James Harper: >>>> Dear List, >>>> >>>> I=C2=B4m working in research and I tought this list could be >>>> a good adress for my questions. >>>> >>>> I want to log the disk accesses of the virtual hvm instances running= in Xen. >>>> That means for the start I want to log the write querys of a running >>>> domU instance in the dom0 instance. >>>> >>>> So I=C2=B4m trying to modify the Xen 3.2.1 source code, >>>> but actually I was not able to find a good entry point to do this. >>>> >>>> For now, I want to log the disk accesses of a running windows 7 domU >>>> instance. >>>> The best what could happenis that I could see even the source and ta= rget >>>> of a hdd write query. >>>> >>>> Does anyone have an idea how I could do this on a good way? >>>> Which Xen source file / function should I modify? Where is the best >>>> entry point to do this? >>> HVM access can either be emulated PCI IDE, or PV. For the emulated ac= cess you would hook into qemu, I think. For PV access you would need to h= ook into whatever block device backend you are using. >>> >>> Do you just want to count reads and writes, or do you want to log eve= ry single byte read/written? >>> >>> James >> I dont need to log every single byte, it would be enough to know which >> file is accessed by the domU inside its image. >> So when I use HVM I need to modify qemu and not the xen source? >> >> thanks >> > Sebastian, QEMU is used by Xen for HVM guests. It's in the Xen source > codes in the tools/ioemu-dir so look there and here it depends on disk > type you're having - whether SCSI or IDE disk or whether you're using P= V > drivers. This can be found in the Xen domain configuration, i.e. if > you're using file:/path/to/image,xvda then you're using PV drivers (the= y > have to be installed in the guest), for hda instead of xvda you're usin= g > IDE disk and for sda instead of xvda you're using SCSI disk. If you're > using PV drivers then you have to modify the PV drivers themselves and > not QEMU so I'd recommend to use SCSI or IDE disk instead. For SCSI dis= k > it's the best since you have the logic in the ioemu-dir/hw/scsi-disk.c > AFAIK. > > Michal > Okay, that sounds good, I will try to modifiy the ioemu ide drivers to see which sectors are used and I will try to match these sectors to the upper layer of the image of the guestU tofind out which data files are accessed. Hope that works :-) Thank you! --=20 Sebastian Biedermann Security Engineering Group Technische Universit=C3=A4t Darmstadt Mornewegstra=C3=9Fe 32, 64293 Darmstadt Phone: +49-6151-16-75146 This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the sender.