zhunxun(a)gmail.com
发件人: zhunxun(a)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(a)gmail.com
From: Daniel P. Berrange
Date: 2016-10-19 15:35
To: Michal Privoznik
CC: zhunxun(a)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(a)gmail.com wrote:
> 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/)
>
> <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Firstly, this is obsolete in favour of "-machine accel=kvm".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).
> <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.
> <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 :-)
> <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
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