1.Description of problem:
It report use migration with shmem device is not supported , when I use
the command "virsh migrate --live" to migrate a VM to another host.
2.Version-Release number of selected component (if applicable):
libvirt 3.9.0
qemu-kvm 2.8.1
3.Steps to Reproduce:
1) Add serveral lines below to guest configuration
<shmem name='my_shmem1'>
<model type='ivshmem-plain'/>
<size unit='M'>4</size>
</shmem>
2) virsh start guest-1
3) virsh migrate --live guest-1 qemu+ssh://target/system
Actual results:
error: Requested operation is not valid: migration with shmem device is
not supported
4.Code Review
When using the command “virsh create guset-1.xml,it produce corresponding
command below.
“qemu-kvm -device ivshmem-plain,
id=shmem0,memdev=shmmem-shmem0,bus=pci.0,addr=0xa”
I read qemu-doc.texi in qemu-2.8.1 source code, which have a explain of
migrating ivshmem below
“With device property @option{master=on}, the guest will copy the shared
memory on migration to the destination host. With @option{master=off},
the guest will not be able to migrate with the device attached.”
But libvirt library can not recognize the property “master=on”. When I directly
used command "qemu-kvm -device
ivshmem-plain,id=shmem0,memdev=shmmem-shmem0,master=on,bus=pci.0,addr=0xa” to
launch a guest, it can migrate in live.
I review the code about qemu code with branch 2.8.1 and master from
https://github.com/libvirt/libvirt, it have no configuration definition for
“master=on”
The below is the part of source code
domain_conf.h
struct _virDomainShmemDef {
char *name;
unsigned long long size;
int model; /* enum virDomainShmemModel */
struct {
bool enabled;
virDomainChrSourceDef chr;
} server;
struct {
bool enabled;
unsigned vectors;
virTristateSwitch ioeventfd;
} msi;
virDomainDeviceInfo info;
};
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