ruby young
2008-Jun-13 08:53 UTC
[Xen-devel] can I boot privilleged dom like dom0 via xm create
Hi all,
I'm using vmlinuz-2.6.18-xen0 as domU kernel and I boot it via *xm
create.* But the kernel didn't panic, it's running but all of xen tools
can
not work. I am surprised at this.
Now My question whether I can boot privilleged dom like dom0 via xm
create ? and how can I do it?
I am looking forwards to your suggestions.
Best wishes
Ruby Young
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
杨漾
北京航空航天大学计算机学院体系结构研究所
电话:010-82338059-132
邮件:9907yruby@gmail.com
地址：北京市海淀区学院路37号北京航空航天大学新主楼 G座1026
--------------------------------------------------------------------------------
Yang Yang
Institute of Computer Architecture and System
BeiHang University（BUAA）
Tel: (86-10)82338059-132
Email: 9907yruby@gmail.com
Addr: Room 1026,Building G,The New Main Building,37# Xueyuan Rd.,Haidian
District, Beijing 100083, PRC
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Derek Murray
2008-Jun-13 10:02 UTC
Re: [Xen-devel] can I boot privilleged dom like dom0 via xm create
Hi Ruby, At present, there is no way to do this with xm. In the hypervisor, each struct domain has an is_privileged attribute (which is at present only set when dom0 is created at boot). You could add a domctl to control the setting of this bit, and then write a small C program that uses do_domctl from libxc to set the privilege on a domain. However, simply running two privileged domains with parallel sets of Xen tools is unlikely to work, for example because you will end up with two instances of XenStore. Regards, Derek Murray. 2008/6/13 ruby young <yangyang@les.buaa.edu.cn>:> Hi all, > I'm using vmlinuz-2.6.18-xen0 as domU kernel and I boot it via xm > create. But the kernel didn't panic, it's running but all of xen tools can > not work. I am surprised at this. > Now My question whether I can boot privilleged dom like dom0 via xm > create ? and how can I do it? > I am looking forwards to your suggestions. > > Best wishes > > Ruby Young > > --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- > 杨漾 > 北京航空航天大学计算机学院体系结构研究所 > 电话:010-82338059-132 > 邮件:9907yruby@gmail.com > 地址：北京市海淀区学院路37号北京航空航天大学新主楼 G座1026 > -------------------------------------------------------------------------------- > Yang Yang > Institute of Computer Architecture and System > BeiHang University（BUAA） > Tel: (86-10)82338059-132 > Email: 9907yruby@gmail.com > Addr: Room 1026,Building G,The New Main Building,37# Xueyuan Rd.,Haidian > District, Beijing 100083, PRC > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Mark Williamson
2008-Jun-18 17:31 UTC
Re: [Xen-devel] can I boot privilleged dom like dom0 via xm create
Ruby, Further to what Derek has said, I''d like to point out that what kernel you use never affects the privilege of the guest. All the -xen0 kernel name means is that the kernel /can/ do dom0 stuff. This is as opposed to a -xenU kernel, which has had the dom0 support removed from it. Removing the dom0 support in a xenU kernel is done /only to make the kernel smaller/. It doesn''t have any effect on security or privilege. Actually, most distributions seem to now supply one -xen kernel that is used both in dom0 and domU. This is because, as Derek mentioned, Xen enforces the privileges of guests itself and doesn''t have to trust their kernels. This is different to how User Mode Linux works, since in that system the kernel itself enforces the virtual machine boundaries. You can securely run any kernel you want in a domU - even one supplied by the user - because Xen will contain it. Cheers, Mark> At present, there is no way to do this with xm. In the hypervisor, > each struct domain has an is_privileged attribute (which is at present > only set when dom0 is created at boot). You could add a domctl to > control the setting of this bit, and then write a small C program that > uses do_domctl from libxc to set the privilege on a domain. > > However, simply running two privileged domains with parallel sets of > Xen tools is unlikely to work, for example because you will end up > with two instances of XenStore. > > Regards, > > Derek Murray. > > 2008/6/13 ruby young <yangyang@les.buaa.edu.cn>: > > Hi all, > > I''m using vmlinuz-2.6.18-xen0 as domU kernel and I boot it via xm > > create. But the kernel didn''t panic, it''s running but all of xen tools > > can not work. I am surprised at this. > > Now My question whether I can boot privilleged dom like dom0 via xm > > create ? and how can I do it? > > I am looking forwards to your suggestions. > > > > Best wishes > > > > Ruby Young > > > > ------------------------------------------------------------------------- > >-------------------------------------------------------------------------- > >------------------------------------------------ 杨漾 > > 北京航空航天大学计算机学院体系结构研究所 > > 电话:010-82338059-132 > > 邮件:9907yruby@gmail.com > > 地址：北京市海淀区学院路37号北京航空航天大学新主楼 G座1026 > > ------------------------------------------------------------------------- > >------- Yang Yang > > Institute of Computer Architecture and System > > BeiHang University（BUAA） > > Tel: (86-10)82338059-132 > > Email: 9907yruby@gmail.com > > Addr: Room 1026,Building G,The New Main Building,37# Xueyuan Rd.,Haidian > > District, Beijing 100083, PRC > > _______________________________________________ > > Xen-devel mailing list > > Xen-devel@lists.xensource.com > > http://lists.xensource.com/xen-devel-- Push Me Pull You - Distributed SCM tool (http://www.cl.cam.ac.uk/~maw48/pmpu/) _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
ruby young
2008-Jun-19 16:49 UTC
Re: [Xen-devel] can I boot privilleged dom like dom0 via xm create
Thanks, Mark What you said helps me a lot! But I have an another quesiton: I compared the configuration of xen, xen0 and xenU(the config file are in the directory named build-linux-2.6.18-xen/xen0/xenU_x86_32). As my expected, xen0 and xenU config the necessary devices they want and xen config more things such as more network options and others. But the size of the kernels is below: *vmlinux-syms-2.6.18-xen 4080677* *vmlinux-syms-2.6.18-xen0 51225377* *vmlinux-syms-2.6.18-xenU 28080922* why the kernel, vmlinux-syms-2.6.18-xen, is the smallest? I think it may be largest. Eager for your answering~ Best wishes ! Ruby Young On 6/19/08, Mark Williamson <mark.williamson@cl.cam.ac.uk> wrote:> > Ruby, > > Further to what Derek has said, I'd like to point out that what kernel you > use > never affects the privilege of the guest. > > All the -xen0 kernel name means is that the kernel /can/ do dom0 > stuff. This > is as opposed to a -xenU kernel, which has had the dom0 support removed > from > it. Removing the dom0 support in a xenU kernel is done /only to make the > kernel smaller/. It doesn't have any effect on security or privilege. > > Actually, most distributions seem to now supply one -xen kernel that is > used > both in dom0 and domU. > > This is because, as Derek mentioned, Xen enforces the privileges of guests > itself and doesn't have to trust their kernels. This is different to how > User Mode Linux works, since in that system the kernel itself enforces the > virtual machine boundaries. You can securely run any kernel you want in a > domU - even one supplied by the user - because Xen will contain it. > > Cheers, > Mark > > > At present, there is no way to do this with xm. In the hypervisor, > > each struct domain has an is_privileged attribute (which is at present > > only set when dom0 is created at boot). You could add a domctl to > > control the setting of this bit, and then write a small C program that > > uses do_domctl from libxc to set the privilege on a domain. > > > > However, simply running two privileged domains with parallel sets of > > Xen tools is unlikely to work, for example because you will end up > > with two instances of XenStore. > > > > Regards, > > > > Derek Murray. > > > > 2008/6/13 ruby young <yangyang@les.buaa.edu.cn>: > > > Hi all, > > > I'm using vmlinuz-2.6.18-xen0 as domU kernel and I boot it via xm > > > create. But the kernel didn't panic, it's running but all of xen tools > > > can not work. I am surprised at this. > > > Now My question whether I can boot privilleged dom like dom0 via xm > > > create ? and how can I do it? > > > I am looking forwards to your suggestions. > > > > > > Best wishes > > > > > > Ruby Young > > > > > > > ------------------------------------------------------------------------- > > > >-------------------------------------------------------------------------- > > >------------------------------------------------ 杨漾 > > > 北京航空航天大学计算机学院体系结构研究所 > > > 电话:010-82338059-132 > > > 邮件:9907yruby@gmail.com > > > 地址：北京市海淀区学院路37号北京航空航天大学新主楼 G座1026 > > > > ------------------------------------------------------------------------- > > >------- Yang Yang > > > Institute of Computer Architecture and System > > > BeiHang University（BUAA） > > > Tel: (86-10)82338059-132 > > > Email: 9907yruby@gmail.com > > > Addr: Room 1026,Building G,The New Main Building,37# Xueyuan > Rd.,Haidian > > > District, Beijing 100083, PRC > > > _______________________________________________ > > > Xen-devel mailing list > > > Xen-devel@lists.xensource.com > > > http://lists.xensource.com/xen-devel > > > > -- > Push Me Pull You - Distributed SCM tool ( > http://www.cl.cam.ac.uk/~maw48/pmpu/) >-- Best wishes 杨漾 北京航空航天大学计算机学院体系结构研究所 电话:010-82338059-132 邮件:9907yruby@gmail.com 地址：北京市海淀区学院路37号北京航空航天大学新主楼 G座1026 -------------------------------------------------------------------------------- Yang Yang Institute of Computer Architecture and System BeiHang University（BUAA） Tel: (86-10)82338059-132 Email: 9907yruby@gmail.com Addr: Room 1026,Building G,The New Main Building,37# Xueyuan Rd.,Haidian District, Beijing 100083, PRC _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Mark Williamson
2008-Jun-20 00:48 UTC
Re: [Xen-devel] can I boot privilleged dom like dom0 via xm create
> But I have an another quesiton: > I compared the configuration of xen, xen0 and xenU(the config file are in > the directory named build-linux-2.6.18-xen/xen0/xenU_x86_32). As my > expected, xen0 and xenU config the necessary devices they want and xen > config more things such as more network options and others. But the size of > the kernels is below: > *vmlinux-syms-2.6.18-xen 4080677* > *vmlinux-syms-2.6.18-xen0 51225377* > *vmlinux-syms-2.6.18-xenU 28080922* > why the kernel, vmlinux-syms-2.6.18-xen, is the smallest? I think it may be > largest.The -xen0 kernel builds a load of drivers statically into the kernel, which is useful mainly for developers. The -xen kernel builds those drivers as modules, which will be loaded later. This makes the basic size of the kernel image smaller, although the modules that are loaded will take up some further space. This approach avoids you wasting memory space on drivers you don''t need. The on disk space is probably bigger because the -xen config builds lots of drivers. Cheers, Mark> > Eager for your answering~ > Best wishes ! > > Ruby Young > > On 6/19/08, Mark Williamson <mark.williamson@cl.cam.ac.uk> wrote: > > Ruby, > > > > Further to what Derek has said, I''d like to point out that what kernel > > you use > > never affects the privilege of the guest. > > > > All the -xen0 kernel name means is that the kernel /can/ do dom0 > > stuff. This > > is as opposed to a -xenU kernel, which has had the dom0 support removed > > from > > it. Removing the dom0 support in a xenU kernel is done /only to make the > > kernel smaller/. It doesn''t have any effect on security or privilege. > > > > Actually, most distributions seem to now supply one -xen kernel that is > > used > > both in dom0 and domU. > > > > This is because, as Derek mentioned, Xen enforces the privileges of > > guests itself and doesn''t have to trust their kernels. This is different > > to how User Mode Linux works, since in that system the kernel itself > > enforces the virtual machine boundaries. You can securely run any kernel > > you want in a domU - even one supplied by the user - because Xen will > > contain it. > > > > Cheers, > > Mark > > > > > At present, there is no way to do this with xm. In the hypervisor, > > > each struct domain has an is_privileged attribute (which is at present > > > only set when dom0 is created at boot). You could add a domctl to > > > control the setting of this bit, and then write a small C program that > > > uses do_domctl from libxc to set the privilege on a domain. > > > > > > However, simply running two privileged domains with parallel sets of > > > Xen tools is unlikely to work, for example because you will end up > > > with two instances of XenStore. > > > > > > Regards, > > > > > > Derek Murray. > > > > > > 2008/6/13 ruby young <yangyang@les.buaa.edu.cn>: > > > > Hi all, > > > > I''m using vmlinuz-2.6.18-xen0 as domU kernel and I boot it via xm > > > > create. But the kernel didn''t panic, it''s running but all of xen > > > > tools can not work. I am surprised at this. > > > > Now My question whether I can boot privilleged dom like dom0 via > > > > xm create ? and how can I do it? > > > > I am looking forwards to your suggestions. > > > > > > > > Best wishes > > > > > > > > Ruby Young > > > > ------------------------------------------------------------------------- > > > > >------------------------------------------------------------------------ > > >-- > > > > > > >------------------------------------------------ 杨漾 > > > > 北京航空航天大学计算机学院体系结构研究所 > > > > 电话:010-82338059-132 > > > > 邮件:9907yruby@gmail.com > > > > 地址：北京市海淀区学院路37号北京航空航天大学新主楼 G座1026 > > > > ------------------------------------------------------------------------- > > > > > >------- Yang Yang > > > > Institute of Computer Architecture and System > > > > BeiHang University（BUAA） > > > > Tel: (86-10)82338059-132 > > > > Email: 9907yruby@gmail.com > > > > Addr: Room 1026,Building G,The New Main Building,37# Xueyuan > > > > Rd.,Haidian > > > > > > District, Beijing 100083, PRC > > > > _______________________________________________ > > > > Xen-devel mailing list > > > > Xen-devel@lists.xensource.com > > > > http://lists.xensource.com/xen-devel > > > > -- > > Push Me Pull You - Distributed SCM tool ( > > http://www.cl.cam.ac.uk/~maw48/pmpu/)-- Push Me Pull You - Distributed SCM tool (http://www.cl.cam.ac.uk/~maw48/pmpu/) _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
tgh
2008-Jun-29 04:20 UTC
Re: [Xen-devel] can I boot privilleged dom like dom0 via xm create
hi I am interested in this issue, and I wonder wether we could manage dom0 in xen architecture, that is ,to boot dom0, to reboot it ,to store it ,or restore it ,while suspending domU in memory ,through some domctl whenever necessary, or could we develop some new hypercall to make it work ,or does xen architecture have some inherent limit in itself and have no compatibility with this potential augment? and why not or how to achieve it , could some one give some advise on it Thanks in advance Mark Williamson 写道:> Ruby, > > Further to what Derek has said, I''d like to point out that what kernel you use > never affects the privilege of the guest. > > All the -xen0 kernel name means is that the kernel /can/ do dom0 stuff. This > is as opposed to a -xenU kernel, which has had the dom0 support removed from > it. Removing the dom0 support in a xenU kernel is done /only to make the > kernel smaller/. It doesn''t have any effect on security or privilege. > > Actually, most distributions seem to now supply one -xen kernel that is used > both in dom0 and domU. > > This is because, as Derek mentioned, Xen enforces the privileges of guests > itself and doesn''t have to trust their kernels. This is different to how > User Mode Linux works, since in that system the kernel itself enforces the > virtual machine boundaries. You can securely run any kernel you want in a > domU - even one supplied by the user - because Xen will contain it. > > Cheers, > Mark > > >> At present, there is no way to do this with xm. In the hypervisor, >> each struct domain has an is_privileged attribute (which is at present >> only set when dom0 is created at boot). You could add a domctl to >> control the setting of this bit, and then write a small C program that >> uses do_domctl from libxc to set the privilege on a domain. >> >> However, simply running two privileged domains with parallel sets of >> Xen tools is unlikely to work, for example because you will end up >> with two instances of XenStore. >> >> Regards, >> >> Derek Murray. >> >> 2008/6/13 ruby young <yangyang@les.buaa.edu.cn>: >> >>> Hi all, >>> I''m using vmlinuz-2.6.18-xen0 as domU kernel and I boot it via xm >>> create. But the kernel didn''t panic, it''s running but all of xen tools >>> can not work. I am surprised at this. >>> Now My question whether I can boot privilleged dom like dom0 via xm >>> create ? and how can I do it? >>> I am looking forwards to your suggestions. >>> >>> Best wishes >>> >>> Ruby Young >>> >>> ------------------------------------------------------------------------- >>> -------------------------------------------------------------------------- >>> ------------------------------------------------ 杨漾 >>> 北京航空航天大学计算机学院体系结构研究所 >>> 电话:010-82338059-132 >>> 邮件:9907yruby@gmail.com >>> 地址：北京市海淀区学院路37号北京航空航天大学新主楼 G座1026 >>> ------------------------------------------------------------------------- >>> ------- Yang Yang >>> Institute of Computer Architecture and System >>> BeiHang University（BUAA） >>> Tel: (86-10)82338059-132 >>> Email: 9907yruby@gmail.com >>> Addr: Room 1026,Building G,The New Main Building,37# Xueyuan Rd.,Haidian >>> District, Beijing 100083, PRC >>> _______________________________________________ >>> Xen-devel mailing list >>> Xen-devel@lists.xensource.com >>> http://lists.xensource.com/xen-devel >>> > > > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Daniel Stodden
2008-Jun-29 10:23 UTC
Re: [Xen-devel] can I boot privilleged dom like dom0 via xm create
On Sun, 2008-06-29 at 12:20 +0800, tgh wrote:> hi > I am interested in this issue, and I wonder wether we could manage > dom0 in xen architecture, that is ,to boot dom0, to reboot it ,to store > it ,or restore it ,while suspending domU in memory ,through some domctl > whenever necessary, or could we develop some new hypercall to make it > work ,or does xen architecture have some inherent limit in itself and > have no compatibility with this potential augment? and why not or > how to achieve it , could some one give some advise on itDom0 maintains a lot of information reflecting overall system state, including that of other guest systems. There''s e.g. xenstore, typically most, if not all of the backend machinery used to serve guests. There''s the qemu device emulation. All of these are stateful interfaces exposed to guests. So you''d have to save/restore all that (volatile) information to rehost other guests seamlessly after a reset. Not like it''s absolutely undoable, but it''d be tricky and still easy to break during upgrades. Then there''s dom0 as the maintenance interface at the foreground of your console machine interface. If that reboot fails, you''re left with a completely nonoperational system, since the VMM provides no (or only minimal) interaction itself. It''s a neat idea, but unlikely to be practical unless you move critical parts of its duties into different VMs, and at that point maybe even not so interesting anymore. Best, Daniel -- Daniel Stodden LRR - Lehrstuhl für Rechnertechnik und Rechnerorganisation Institut für Informatik der TU München D-85748 Garching http://www.lrr.in.tum.de/~stodden mailto:stodden@cs.tum.edu PGP Fingerprint: F5A4 1575 4C56 E26A 0B33 3D80 457E 82AE B0D8 735B _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel