[Qemu-devel] Logging dirty pages from vhost-net in-kernel with vIOMMU

[Jintack Lim]

Hi,

I'm wondering how the current implementation works when logging dirty
pages during migration from vhost-net (in kernel) when used vIOMMU.

I understand how vhost-net logs GPAs when not using vIOMMU. But when
we use vhost with vIOMMU, then shouldn't vhost-net need to log the
translated address (GPA) instead of the address written in the
descriptor (IOVA) ? The current implementation looks like vhost-net
just logs IOVA without translation in vhost_get_vq_desc() in
drivers/vhost/net.c. It seems like QEMU doesn't do any further
translation of the dirty log when syncing.

I might be missing something. Could somebody shed some light on this?

Thanks,
Jintack