zhunxun@gmail.com 发件人： zhunxun@gmail.com 发送时间： 2016-10-23 17:42 收件人： berrange 主题： Re: Re: [libvirt] How libvirt address qemu command line args Thanks，However,I have to use this method.Now I wander how get the VM xml contents in Libvirt source code,I try output some message in qemuProcessStart function like this ,but I get nothing,anyone can help me?? thanks! my code is : in qemuStartProcess function char *str=qemuDomainDefFormatXML(driver, vm->def, 0); FILE *op=fopen("/root/libvirt.log","a"); if(op!=NULL){ if(str!=NULL) fprintf(op,"str----cmd : %s\n",str); else fprintf(op,"str is null\n"); fclose(op); }else{ fprintf(op,"open file error!\n"); } zhunxun@gmail.com From: Daniel P. Berrange Date: 2016-10-19 15:35 To: Michal Privoznik CC: zhunxun@gmail.com; libvir-list Subject: Re: [libvirt] How libvirt address qemu command line args On Wed, Oct 19, 2016 at 10:17:21AM +0800, Michal Privoznik wrote:

On 18.10.2016 14:59, zhunxun@gmail.com wrote:

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Now I want to add some args about TPM to domain's XML,so I can start a domain by virt-manager or other virsh command,and then ,I would like to use sVIrt security context to label vTPM and correspondingVM,But I do not know how to get these XML args in libvirt. the key problem is that how can i get and recognize these args!!! related XML content :

Usually, grepping the code for cmd name <-> XML element/attribute translation is sufficient (esp. if you grep tests/)

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<qemu:commandline> <qemu:arg value='-enable-kvm'/>

Firstly, this is obsolete in favour of "-machine accel=kvm". In any case, <domain type='kvm'/> will do the trick (libvirt will use whatever is supported by qemu binary in your system).

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<qemu:arg value='-drive'/> <qemu:arg value='file=/root/nvram_2.0-jin.qcow2,if=none,id=nvram0-0-0,format=qcow2'/>

Okay, this is not supported by libvirt yet. We don't really have a way how to specify NVRAM in anything other than a raw file. BTW: isn't qcow too big gun for NVRAM? I mean, NVRAM has a fixed size of what ~190 KB? QCOW header is about the same size.

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<qemu:arg value='-device'/> <qemu:arg value='tpm-tis,tpmdev=tpm-tpm0,id=tpm0'/> <qemu:arg value='-tpmdev'/> <qemu:arg value='libtpms,id=tpm-tpm0,nvram=nvram0-0-0,startup=clear'/>

I'm not sure there's a way how to put startup=clean on the cmd line. I'm not even sure what it does. And I have not idea what libtpms is either :-)

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<qemu:arg value='-bios'/> <qemu:arg value='/root/xenSeabios/out/bios.bin'/> </qemu:commandline>

On top of all that - QEMU is likely to fail to start since libvirt by default runs it as qemu:qemu user/group, and so it won't have permission to read any of the files in /root. If you have selinux/apparmour that will also block permission. This is an example of why usage of qemu:commandline is discouraged - it will always have problems with permissions if you pass files using it. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|