|
From: | Anthony Liguori |
Subject: | [Qemu-devel] Re: [PATCH 0/4] Block DMA helpers (v2) |
Date: | Sat, 07 Feb 2009 17:50:29 -0600 |
User-agent: | Thunderbird 2.0.0.19 (X11/20090105) |
Avi Kivity wrote:
Anthony Liguori wrote:This requires that the generic layer be able to tell where a request ends; don't know if that's the case now.Maybe create a sub QEMUSGList from another QEMUSGList. The other option is passing an offset and size to anything that takes a QEMUSGList. You could potentially get smart with how sub SG lists were managed by making them just store an internal offset/size. Although things start to get overly complex at some stage.Lifetime issues will kill us. I note that something resembling this sort of cleverness is holding up copyless networking -- different parts of an skb have different lifetimes.
Yup.
But I thought of something simpler: have virtio call virtio-* to inquire whether a ring entry terminates a request. This would also simplify the virtio device emulations somewhat.
I don't know that I follow what you mean by "terminates a request". I'm not sure I know what problem you're talking about solving.
Regards, Anthony Liguori
[Prev in Thread] | Current Thread | [Next in Thread] |