From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v2 19/24] vdpa: make sure set_features in invoked for legacy
Date: Thu, 6 Aug 2020 01:53:08 -0400 [thread overview]
Message-ID: <20200806015112-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <bd915b30-0604-da1b-343f-e228bce4d1d8@redhat.com>
On Thu, Aug 06, 2020 at 11:23:05AM +0800, Jason Wang wrote:
>
> On 2020/8/5 下午7:40, Michael S. Tsirkin wrote:
> > On Wed, Aug 05, 2020 at 02:14:07PM +0800, Jason Wang wrote:
> > > On 2020/8/4 上午5:00, Michael S. Tsirkin wrote:
> > > > Some legacy guests just assume features are 0 after reset.
> > > > We detect that config space is accessed before features are
> > > > set and set features to 0 automatically.
> > > > Note: some legacy guests might not even access config space, if this is
> > > > reported in the field we might need to catch a kick to handle these.
> > > I wonder whether it's easier to just support modern device?
> > >
> > > Thanks
> > Well hardware vendors are I think interested in supporting legacy
> > guests. Limiting vdpa to modern only would make it uncompetitive.
>
>
> My understanding is that, IOMMU_PLATFORM is mandatory for hardware vDPA to
> work.
Hmm I don't really see why. Assume host maps guest memory properly,
VM does not have an IOMMU, legacy guest can just work.
Care explaining what's wrong with this picture?
> So it can only work for modern device ...
>
> Thanks
>
>
> >
> >
> >
WARNING: multiple messages have this Message-ID (diff)
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org
Subject: Re: [PATCH v2 19/24] vdpa: make sure set_features in invoked for legacy
Date: Thu, 6 Aug 2020 01:53:08 -0400 [thread overview]
Message-ID: <20200806015112-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <bd915b30-0604-da1b-343f-e228bce4d1d8@redhat.com>
On Thu, Aug 06, 2020 at 11:23:05AM +0800, Jason Wang wrote:
>
> On 2020/8/5 下午7:40, Michael S. Tsirkin wrote:
> > On Wed, Aug 05, 2020 at 02:14:07PM +0800, Jason Wang wrote:
> > > On 2020/8/4 上午5:00, Michael S. Tsirkin wrote:
> > > > Some legacy guests just assume features are 0 after reset.
> > > > We detect that config space is accessed before features are
> > > > set and set features to 0 automatically.
> > > > Note: some legacy guests might not even access config space, if this is
> > > > reported in the field we might need to catch a kick to handle these.
> > > I wonder whether it's easier to just support modern device?
> > >
> > > Thanks
> > Well hardware vendors are I think interested in supporting legacy
> > guests. Limiting vdpa to modern only would make it uncompetitive.
>
>
> My understanding is that, IOMMU_PLATFORM is mandatory for hardware vDPA to
> work.
Hmm I don't really see why. Assume host maps guest memory properly,
VM does not have an IOMMU, legacy guest can just work.
Care explaining what's wrong with this picture?
> So it can only work for modern device ...
>
> Thanks
>
>
> >
> >
> >
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next prev parent reply other threads:[~2020-08-06 11:04 UTC|newest]
Thread overview: 143+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-03 20:58 [PATCH v2 00/24] virtio: config space endian-ness cleanup Michael S. Tsirkin
2020-08-03 20:58 ` Michael S. Tsirkin
2020-08-03 20:58 ` [PATCH v2 01/24] virtio_balloon: fix sparse warning Michael S. Tsirkin
2020-08-03 20:58 ` Michael S. Tsirkin
2020-08-03 21:25 ` David Hildenbrand
2020-08-03 21:25 ` David Hildenbrand
2020-08-04 14:16 ` Cornelia Huck
2020-08-04 14:16 ` Cornelia Huck
2020-08-03 20:58 ` [PATCH v2 02/24] virtio_ring: sparse warning fixup Michael S. Tsirkin
2020-08-03 20:58 ` Michael S. Tsirkin
2020-08-04 14:18 ` Cornelia Huck
2020-08-04 14:18 ` Cornelia Huck
2020-08-03 20:58 ` [PATCH v2 03/24] virtio: allow __virtioXX, __leXX in config space Michael S. Tsirkin
2020-08-03 20:58 ` Michael S. Tsirkin
2020-08-04 14:23 ` Cornelia Huck
2020-08-04 14:23 ` Cornelia Huck
2020-08-04 14:28 ` Michael S. Tsirkin
2020-08-04 14:28 ` Michael S. Tsirkin
2020-08-05 6:28 ` Jason Wang
2020-08-05 6:28 ` Jason Wang
2020-08-05 11:45 ` Michael S. Tsirkin
2020-08-05 11:45 ` Michael S. Tsirkin
2020-08-06 3:37 ` Jason Wang
2020-08-06 3:37 ` Jason Wang
2020-08-06 5:58 ` Michael S. Tsirkin
2020-08-06 5:58 ` Michael S. Tsirkin
2020-08-07 3:26 ` Jason Wang
2020-08-07 3:26 ` Jason Wang
2020-08-03 20:58 ` [PATCH v2 04/24] virtio_9p: correct tags for config space fields Michael S. Tsirkin
2020-08-03 20:58 ` Michael S. Tsirkin
2020-08-04 14:25 ` Cornelia Huck
2020-08-04 14:25 ` Cornelia Huck
2020-08-03 20:58 ` [PATCH v2 05/24] virtio_balloon: " Michael S. Tsirkin
2020-08-03 20:58 ` Michael S. Tsirkin
2020-08-03 21:26 ` David Hildenbrand
2020-08-03 21:26 ` David Hildenbrand
2020-08-04 14:26 ` Cornelia Huck
2020-08-04 14:26 ` Cornelia Huck
2020-08-03 20:58 ` [PATCH v2 06/24] virtio_blk: " Michael S. Tsirkin
2020-08-03 20:58 ` Michael S. Tsirkin
2020-08-04 14:29 ` Cornelia Huck
2020-08-04 14:29 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 07/24] virtio_console: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 14:31 ` Cornelia Huck
2020-08-04 14:31 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 08/24] virtio_crypto: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 14:32 ` Cornelia Huck
2020-08-04 14:32 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 09/24] virtio_fs: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 13:36 ` Vivek Goyal
2020-08-04 13:36 ` Vivek Goyal
2020-08-04 14:33 ` Cornelia Huck
2020-08-04 14:33 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 10/24] virtio_gpu: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 14:34 ` Cornelia Huck
2020-08-04 14:34 ` Cornelia Huck
2020-08-04 14:34 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 11/24] virtio_input: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 6:01 ` Gerd Hoffmann
2020-08-04 6:01 ` Gerd Hoffmann
2020-08-04 14:35 ` Cornelia Huck
2020-08-04 14:35 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 12/24] virtio_iommu: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 8:00 ` Jean-Philippe Brucker
2020-08-04 8:00 ` Jean-Philippe Brucker
2020-08-04 14:36 ` Cornelia Huck
2020-08-04 14:36 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 13/24] virtio_mem: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-03 21:23 ` David Hildenbrand
2020-08-03 21:23 ` David Hildenbrand
2020-08-04 14:37 ` Cornelia Huck
2020-08-04 14:37 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 14/24] virtio_net: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 14:44 ` Cornelia Huck
2020-08-04 14:44 ` Cornelia Huck
2020-08-05 13:26 ` Michael S. Tsirkin
2020-08-05 13:26 ` Michael S. Tsirkin
2020-08-03 20:59 ` [PATCH v2 15/24] virtio_pmem: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 14:46 ` Cornelia Huck
2020-08-04 14:46 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 16/24] virtio_scsi: " Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 14:48 ` Cornelia Huck
2020-08-04 14:48 ` Cornelia Huck
2020-08-03 20:59 ` [PATCH v2 17/24] virtio_config: disallow native type fields Michael S. Tsirkin
2020-08-03 20:59 ` Michael S. Tsirkin
2020-08-04 14:50 ` Cornelia Huck
2020-08-04 14:50 ` Cornelia Huck
2020-08-05 13:29 ` Michael S. Tsirkin
2020-08-05 13:29 ` Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 18/24] mlxbf-tmfifo: sparse tags for config access Michael S. Tsirkin
2020-08-03 21:00 ` Michael S. Tsirkin
2020-08-03 21:00 ` Michael S. Tsirkin
2020-08-04 14:56 ` Cornelia Huck
2020-08-04 14:56 ` Cornelia Huck
2020-08-04 14:56 ` Cornelia Huck
2020-08-05 13:29 ` Michael S. Tsirkin
2020-08-05 13:29 ` Michael S. Tsirkin
2020-08-05 13:29 ` Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 19/24] vdpa: make sure set_features in invoked for legacy Michael S. Tsirkin
2020-08-03 21:00 ` Michael S. Tsirkin
2020-08-05 6:14 ` Jason Wang
2020-08-05 6:14 ` Jason Wang
2020-08-05 11:40 ` Michael S. Tsirkin
2020-08-05 11:40 ` Michael S. Tsirkin
2020-08-06 3:23 ` Jason Wang
2020-08-06 3:23 ` Jason Wang
2020-08-06 5:53 ` Michael S. Tsirkin [this message]
2020-08-06 5:53 ` Michael S. Tsirkin
2020-08-06 7:27 ` Jason Wang
2020-08-06 7:27 ` Jason Wang
2020-08-06 10:00 ` Michael S. Tsirkin
2020-08-06 10:00 ` Michael S. Tsirkin
2020-08-07 3:00 ` Jason Wang
2020-08-07 3:00 ` Jason Wang
2020-08-03 21:00 ` [PATCH v2 20/24] vhost/vdpa: switch to new helpers Michael S. Tsirkin
2020-08-03 21:00 ` Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 21/24] virtio_vdpa: legacy features handling Michael S. Tsirkin
2020-08-03 21:00 ` Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 22/24] vdpa_sim: fix endian-ness of config space Michael S. Tsirkin
2020-08-03 21:00 ` Michael S. Tsirkin
2020-08-05 6:21 ` Jason Wang
2020-08-05 6:21 ` Jason Wang
2020-08-05 11:44 ` Michael S. Tsirkin
2020-08-05 11:44 ` Michael S. Tsirkin
2020-08-05 12:06 ` Michael S. Tsirkin
2020-08-05 12:06 ` Michael S. Tsirkin
2020-08-06 3:23 ` Jason Wang
2020-08-06 3:23 ` Jason Wang
2020-08-03 21:00 ` [PATCH v2 23/24] virtio_config: cread/write cleanup Michael S. Tsirkin
2020-08-03 21:00 ` Michael S. Tsirkin
2020-08-03 21:00 ` [PATCH v2 24/24] virtio_config: rewrite using _Generic Michael S. Tsirkin
2020-08-03 21:00 ` Michael S. Tsirkin
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