[ovs-dev] [PATCH V6 2/2] netdev-dpdk: vHost IOMMU support

Kevin Traynor ktraynor at redhat.com
Fri Dec 8 11:20:29 UTC 2017


On 12/08/2017 10:53 AM, Mark Kavanagh wrote:
> DPDK v17.11 introduces support for the vHost IOMMU feature.
> This is a security feature, which restricts the vhost memory
> that a virtio device may access.
> 
> This feature also enables the vhost REPLY_ACK protocol, the
> implementation of which is known to work in newer versions of
> QEMU (i.e. v2.10.0), but is buggy in older versions (v2.7.0 -
> v2.9.0, inclusive). As such, the feature is disabled by default
> in (and should remain so), for the aforementioned older QEMU
> verions. Starting with QEMU v2.9.1, vhost-iommu-support can
> safely be enabled, even without having an IOMMU device, with
> no performance penalty.
> 
> This patch adds a new global config option, vhost-iommu-support,
> that controls enablement of the vhost IOMMU feature:
> 
>     ovs-vsctl set Open_vSwitch . other_config:vhost-iommu-support=true
> 
> This value defaults to false; to enable IOMMU support, this field
> should be set to true when setting other global parameters on init
> (such as "dpdk-socket-mem", for example). Changing the value at
> runtime is not supported, and requires restarting the vswitch daemon.
> 
> Signed-off-by: Mark Kavanagh <mark.b.kavanagh at intel.com>

Acked-by: Kevin Traynor <ktraynor at redhat.com>


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