From: Jason Wang <jasowang@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>, Tiwei Bie <tiwei.bie@intel.com>
Cc: peterx@redhat.com, qemu-devel@nongnu.org, dan.daly@intel.com,
cunming.liang@intel.com, zhihong.wang@intel.com
Subject: Re: [Qemu-devel] [RFC] vhost-user: introduce F_NEED_ALL_IOTLB protocol feature
Date: Wed, 11 Apr 2018 21:42:36 +0800 [thread overview]
Message-ID: <b8e19751-9cb8-331d-a464-35babdfb9ca2@redhat.com> (raw)
In-Reply-To: <20180411161926-mutt-send-email-mst@kernel.org>
On 2018年04月11日 21:22, Michael S. Tsirkin wrote:
> On Wed, Apr 11, 2018 at 03:20:27PM +0800, Tiwei Bie wrote:
>> This patch introduces VHOST_USER_PROTOCOL_F_NEED_ALL_IOTLB
>> feature for vhost-user. By default, vhost-user backend needs
>> to query the IOTLBs from QEMU after meeting unknown IOVAs.
>> With this protocol feature negotiated, QEMU will provide all
>> the IOTLBs to vhost-user backend without waiting for the
>> queries from backend. This is helpful when using a hardware
>> accelerator which is not able to handle unknown IOVAs at the
>> vhost-user backend.
>>
>> Signed-off-by: Tiwei Bie<tiwei.bie@intel.com>
> This is potentially a large amount of data to be sent
> on a socket.
>
> I had an impression that a hardware accelerator was using
> VFIO anyway. Given this, can't we have QEMU program
> the shadow IOMMU tables into VFIO directly?
>
>
So if we want to do this, my understanding is we need to implement the
driver inside qemu (or link it to qemu).
Thanks
next prev parent reply other threads:[~2018-04-11 13:42 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-11 7:20 [Qemu-devel] [RFC] vhost-user: introduce F_NEED_ALL_IOTLB protocol feature Tiwei Bie
2018-04-11 8:00 ` Peter Xu
2018-04-11 8:25 ` Tiwei Bie
2018-04-11 8:37 ` Peter Xu
2018-04-11 8:55 ` Tiwei Bie
2018-04-11 9:16 ` Peter Xu
2018-04-11 9:25 ` Tiwei Bie
2018-04-11 8:01 ` Jason Wang
2018-04-11 8:38 ` Tiwei Bie
2018-04-11 13:41 ` Jason Wang
2018-04-11 17:00 ` Michael S. Tsirkin
2018-04-12 3:23 ` Jason Wang
2018-04-12 3:37 ` Michael S. Tsirkin
2018-04-12 3:56 ` Jason Wang
2018-04-11 17:37 ` Michael S. Tsirkin
2018-04-12 1:44 ` Tiwei Bie
2018-04-12 7:38 ` Jason Wang
2018-04-12 8:10 ` Tiwei Bie
2018-04-12 9:40 ` Jason Wang
2018-04-11 13:22 ` Michael S. Tsirkin
2018-04-11 13:42 ` Jason Wang [this message]
2018-04-12 1:10 ` Tiwei Bie
2018-04-12 1:29 ` Michael S. Tsirkin
2018-04-12 1:39 ` Tiwei Bie
2018-04-12 1:57 ` Michael S. Tsirkin
2018-04-12 2:35 ` Tiwei Bie
2018-04-12 3:20 ` Michael S. Tsirkin
2018-04-12 3:35 ` Michael S. Tsirkin
2018-04-12 3:43 ` Jason Wang
2018-04-12 4:19 ` Michael S. Tsirkin
2018-04-12 3:37 ` Jason Wang
2018-04-12 3:41 ` Michael S. Tsirkin
2018-04-12 7:24 ` Jason Wang
2018-04-16 7:47 ` Stefan Hajnoczi
2018-04-17 2:14 ` Jason Wang
2018-04-17 2:35 ` Tiwei Bie
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