On Thu, Aug 11, 2016 at 09:27:47AM +0100, Daniel P. Berrange wrote:
On Wed, Aug 10, 2016 at 01:50:11PM +0200, Martin Kletzander wrote:QEMU added support for ivshmem-plain and ivshmem-doorbell. Those are reworked varians of legacy ivshmem that are compatible, but have sane specification and handling. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1347049 Signed-off-by: Martin Kletzander <mkletzan@xxxxxxxxxx> --- src/qemu/qemu_command.c | 66 ++++++++++++++++++++-- .../qemuxml2argv-shmem-plain-doorbell.args | 42 ++++++++++++++ .../qemuxml2argv-shmem-plain-doorbell.xml | 54 ++++++++++++++++++ tests/qemuxml2argvtest.c | 3 + 4 files changed, 161 insertions(+), 4 deletions(-) create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-shmem-plain-doorbell.args create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-shmem-plain-doorbell.xmlIsn't this going to break migration compatibility. eg if someone has a guest running on a QEMU with ivshmem, which also has the ivshmem-plain, then when they upgrade libvirt their guest will guest the different device, which has different migration ABI ? Or is there a blocker that entirely prevents migration with ivshmem, making it a non-issue ?
ivshmem migration is forbidden if the role is "master". It now makes sense with the new ivshmem-plain, but didn't make much sense with the old one, so we didn't add support for it. Thanks to that we can make old ones just role=peer and the new ones to role=master (which are the qemu defaults anyway) and then we can check that in the ABI stability check. I forgot to do that, good point. However, I need to make sure that migration works from legacy to ivshmem-plain, otherwise we'd need to either add a model (I wouldn't like that) or forbid migration based on qemu capabilities and migration cookie flag. I'll have a look at that.
Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
Attachment:
signature.asc
Description: Digital signature
-- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list