Thread (38 messages) flat view 38 messages, 5 authors, 2021-06-04

Re: [PATCH v1 1/8] virtio: Force only split mode with protected guest

From: Jason Wang <hidden>
Date: 2021-06-04 01:29:21
Also in: linux-iommu, lkml

在 2021/6/4 上午2:00, Andi Kleen 写道:
On 6/3/2021 10:33 AM, Andy Lutomirski wrote:
quoted
On 6/2/21 5:41 PM, Andi Kleen wrote:
quoted
Only allow split mode when in a protected guest. Followon
patches harden the split mode code paths, and we don't want
an malicious host to force anything else. Also disallow
indirect mode for similar reasons.
I read this as "the virtio driver is buggy.  Let's disable most of the
buggy code in one special case in which we need a driver without bugs.
In all the other cases (e.g. hardware virtio device connected over
USB-C), driver bugs are still allowed."
My understanding is most of the other modes (except for split with 
separate descriptors) are obsolete and just there for compatibility. 
As long as they're deprecated they won't harm anyone.

-Andi
For "mode" do you packed vs split? If yes, it's not just for 
compatibility. Though packed virtqueue is designed to be more hardware 
friendly, most hardware vendors choose to start from split.

Thanks

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help