<div>oh, there is much much much code,it's too too too hard for me. So,,,,,can i ask more question:use virt-manager create a domain,but with a result of "unsupported configuration:the ioh3420 controller is not supported in this qemu".since it's arm64 platform,and ioh3420 is a intel device.right?Why produce a intel device in arm64 platform? So, can i delete the ioh3420 only by changing the code?info: i use the libvirt-2.0.0,virt-manager create doamin succeed;when i update to libvirt-3.2.0,the issue above happened. qemu is 2.3.0 Thanks! </div>-- Have a good day <pre>> -----原始邮件----- > 发件人: Michal Privoznik <mprivozn@redhat.com> > 发送时间: 2018年4月26日星期四 > 收件人: "李卓瑶" <lizhuoyao@hikdata.com> > 抄送: libvirt-users <libvirt-users@redhat.com>, shengyizju@163.com > 主题: Re: [libvirt-users] how xml generated > > On 04/26/2018 09:50 AM, 李卓瑶 wrote: > > Thanks for your reply > > what i want to know is that why there are many devices in $domain.xml, actully , i choose nothing in virt-manager? > > so, Do i need to look at qemuDomainDefineXMLFlags()? > > Because we try to have 1:1 relationship between domain XML configuration > and devices as seen by guest. Even when you don't select anything in > virt-manager the domain will definitely have a PCI root controller, > controller for disk bus (be it sata, scsi, ide, ..), then it'll also > have a virtual NIC, some memory/cpu configuration, and so on. > > In the code, these devices are added once XML is parsed by > virDomainDefPostParseInternal(). Each driver can pass this xmlopt > structure filled in with callbacks (take a look at > virQEMUDriverCreateXMLConf()). So in the end, devices are added only > after XML is parsed. However, it is not done all in one place. For > instance, controllers are added during device address assignment, other > devices are added in PostParse callbacks, and so on. > > > hours ago, i thought it's qemuDomainCreateWithFlags. > > No. This creates so called transient domains. > > https://wiki.libvirt.org/page/VM_lifecycle#Transient_guest_domains_vs_Persistent_guest_domains > > Michal </pre>