Hi On Mon, Jul 13, 2015 at 4:27 AM, Linhaifeng <haifeng....@huawei.com> wrote: >> When a packet is received by vhost-user, the vhost-user writes the >> packet in guest memory. QEMU must then copy that page of guest memory >> from source to destination; it uses a dirty bitmap for this purpose. >> >> How does vhost-user do this? I can see this patch providing enough >> support for *non*live migration. However, it cannot be enough for live >> migration unless I'm missing something obvious. >> >> Paolo > > Agree. vhost-user should mmap the log memory and mark dirty pages when send > or receive packets.
This is already supported by vhost-user protocol, isn't it? The LOG_BASE/FD and vring log_guest_addr are provided. I can't find any vhost-user backend implementing dirty bitmaps yet though, but it looks like it should work. I suppose the backend should stop all IO after RESET_OWNER is received. -- Marc-André Lureau
