From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: kvm@vger.kernel.org, maorg@nvidia.com,
virtualization@lists.linux-foundation.org, jiri@nvidia.com,
leonro@nvidia.com
Subject: Re: [PATCH vfio 11/11] vfio/virtio: Introduce a vfio driver over virtio devices
Date: Thu, 21 Sep 2023 16:16:25 -0400 [thread overview]
Message-ID: <20230921155834-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20230921195345.GZ13733@nvidia.com>
On Thu, Sep 21, 2023 at 04:53:45PM -0300, Jason Gunthorpe wrote:
> On Thu, Sep 21, 2023 at 03:34:03PM -0400, Michael S. Tsirkin wrote:
>
> > that's easy/practical. If instead VDPA gives the same speed with just
> > shadow vq then keeping this hack in vfio seems like less of a problem.
> > Finally if VDPA is faster then maybe you will reconsider using it ;)
>
> It is not all about the speed.
>
> VDPA presents another large and complex software stack in the
> hypervisor that can be eliminated by simply using VFIO.
If all you want is passing through your card to guest
then yes this can be addressed "by simply using VFIO".
And let me give you a simple example just from this patchset:
it assumes guest uses MSIX and just breaks if it doesn't.
As VDPA emulates it can emulate INT#x for guest while doing MSI
on the host side. Yea modern guests use MSIX but this is about legacy
yes?
> VFIO is
> already required for other scenarios.
Required ... by some people? Most VMs I run don't use anything
outside of virtio.
> This is about reducing complexity, reducing attack surface and
> increasing maintainability of the hypervisor environment.
>
> Jason
Generally you get better security if you don't let guests poke at
hardware when they don't have to. But sure, matter of preference -
use VFIO, it's great. I am worried about the specific patchset though.
It seems to deal with emulating virtio which seems more like a vdpa
thing. If you start adding virtio emulation to vfio then won't
you just end up with another vdpa? And if no why not?
And I don't buy the "we already invested in this vfio based solution",
sorry - that's not a reason upstream has to maintain it.
--
MST
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next prev parent reply other threads:[~2023-09-21 20:16 UTC|newest]
Thread overview: 140+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-21 12:40 [PATCH vfio 00/11] Introduce a vfio driver over virtio devices Yishai Hadas via Virtualization
2023-09-21 12:40 ` [PATCH vfio 01/11] virtio-pci: Use virtio pci device layer vq info instead of generic one Yishai Hadas via Virtualization
2023-09-21 13:46 ` Michael S. Tsirkin
2023-09-26 19:13 ` Feng Liu via Virtualization
2023-09-27 18:09 ` Feng Liu via Virtualization
2023-09-27 21:24 ` Michael S. Tsirkin
2023-09-21 12:40 ` [PATCH vfio 02/11] virtio: Define feature bit for administration virtqueue Yishai Hadas via Virtualization
2023-09-21 12:40 ` [PATCH vfio 03/11] virtio-pci: Introduce admin virtqueue Yishai Hadas via Virtualization
2023-09-21 13:57 ` Michael S. Tsirkin
2023-09-26 19:23 ` Feng Liu via Virtualization
2023-09-27 18:12 ` Feng Liu via Virtualization
2023-09-27 21:27 ` Michael S. Tsirkin
2023-10-02 18:07 ` Feng Liu via Virtualization
2023-09-21 12:40 ` [PATCH vfio 04/11] virtio: Expose the synchronous command helper function Yishai Hadas via Virtualization
2023-09-21 12:40 ` [PATCH vfio 05/11] virtio-pci: Introduce admin command sending function Yishai Hadas via Virtualization
2023-09-21 12:40 ` [PATCH vfio 06/11] virtio-pci: Introduce API to get PF virtio device from VF PCI device Yishai Hadas via Virtualization
2023-09-21 12:40 ` [PATCH vfio 07/11] virtio-pci: Introduce admin commands Yishai Hadas via Virtualization
2023-09-24 5:18 ` kernel test robot
2023-09-25 3:18 ` kernel test robot
2023-09-21 12:40 ` [PATCH vfio 08/11] vfio/pci: Expose vfio_pci_core_setup_barmap() Yishai Hadas via Virtualization
2023-09-21 16:35 ` Alex Williamson
2023-09-26 9:45 ` Yishai Hadas via Virtualization
2023-09-21 12:40 ` [PATCH vfio 09/11] vfio/pci: Expose vfio_pci_iowrite/read##size() Yishai Hadas via Virtualization
2023-09-21 12:40 ` [PATCH vfio 10/11] vfio/virtio: Expose admin commands over virtio device Yishai Hadas via Virtualization
2023-09-21 13:08 ` Michael S. Tsirkin
2023-09-21 20:34 ` Michael S. Tsirkin
2023-09-26 10:51 ` Yishai Hadas via Virtualization
2023-09-26 11:25 ` Michael S. Tsirkin
2023-09-22 9:54 ` Michael S. Tsirkin
2023-09-26 11:14 ` Yishai Hadas via Virtualization
2023-09-26 11:41 ` Michael S. Tsirkin
[not found] ` <20230927131817.GA338226@nvidia.com>
2023-09-27 21:30 ` Michael S. Tsirkin
[not found] ` <20230927231600.GD339126@nvidia.com>
2023-09-28 5:26 ` Michael S. Tsirkin
2023-10-02 6:28 ` Christoph Hellwig
[not found] ` <20231002151320.GA650762@nvidia.com>
2023-10-05 8:49 ` Christoph Hellwig
[not found] ` <20231005111004.GK682044@nvidia.com>
2023-10-06 13:09 ` Christoph Hellwig
[not found] ` <20231010131031.GJ3952@nvidia.com>
2023-10-10 13:56 ` Michael S. Tsirkin
[not found] ` <20231010140849.GL3952@nvidia.com>
2023-10-10 14:54 ` Michael S. Tsirkin
2023-10-10 15:09 ` Yishai Hadas via Virtualization
2023-10-10 15:14 ` Michael S. Tsirkin
2023-10-10 15:43 ` Yishai Hadas via Virtualization
2023-10-10 15:58 ` Parav Pandit via Virtualization
2023-10-10 15:58 ` Michael S. Tsirkin
2023-10-10 16:09 ` Yishai Hadas via Virtualization
2023-10-10 20:42 ` Michael S. Tsirkin
2023-10-11 7:44 ` Yishai Hadas via Virtualization
2023-10-11 8:02 ` Michael S. Tsirkin
2023-10-11 8:58 ` Yishai Hadas via Virtualization
2023-10-11 9:03 ` Michael S. Tsirkin
2023-10-11 11:25 ` Yishai Hadas via Virtualization
2023-10-11 6:12 ` Christoph Hellwig
[not found] ` <20231010155937.GN3952@nvidia.com>
2023-10-10 16:03 ` Michael S. Tsirkin
[not found] ` <20231010160712.GO3952@nvidia.com>
2023-10-10 16:21 ` Parav Pandit via Virtualization
2023-10-10 20:38 ` Michael S. Tsirkin
2023-10-11 6:13 ` Christoph Hellwig
2023-10-11 6:43 ` Michael S. Tsirkin
2023-10-11 6:59 ` Christoph Hellwig
2023-10-11 8:00 ` Parav Pandit via Virtualization
2023-10-11 8:10 ` Michael S. Tsirkin
[not found] ` <20231011121849.GV3952@nvidia.com>
2023-10-11 17:03 ` Michael S. Tsirkin
2023-10-11 17:05 ` Michael S. Tsirkin
2023-10-12 10:29 ` Zhu, Lingshan
[not found] ` <20231012132749.GK3952@nvidia.com>
2023-10-13 10:28 ` Zhu, Lingshan
2023-10-13 13:50 ` Michael S. Tsirkin
2023-10-16 8:33 ` Zhu, Lingshan
2023-10-16 8:52 ` Michael S. Tsirkin
2023-10-16 9:53 ` Zhu, Lingshan
2023-10-11 8:12 ` Michael S. Tsirkin
2023-10-12 10:30 ` Zhu, Lingshan
2023-10-11 6:26 ` Christoph Hellwig
[not found] ` <20231011135709.GW3952@nvidia.com>
2023-10-11 14:17 ` Christoph Hellwig
[not found] ` <20231011145810.GZ3952@nvidia.com>
2023-10-11 16:59 ` Michael S. Tsirkin
[not found] ` <20231011171944.GA3952@nvidia.com>
2023-10-11 20:20 ` Michael S. Tsirkin
2023-09-21 12:40 ` [PATCH vfio 11/11] vfio/virtio: Introduce a vfio driver over virtio devices Yishai Hadas via Virtualization
2023-09-21 13:16 ` Michael S. Tsirkin
[not found] ` <20230921141125.GM13733@nvidia.com>
2023-09-21 14:16 ` Michael S. Tsirkin
[not found] ` <20230921164139.GP13733@nvidia.com>
2023-09-21 16:53 ` Michael S. Tsirkin
[not found] ` <20230921183926.GV13733@nvidia.com>
2023-09-21 19:13 ` Michael S. Tsirkin
[not found] ` <20230921194946.GX13733@nvidia.com>
2023-09-21 20:45 ` Michael S. Tsirkin
[not found] ` <20230921225526.GE13733@nvidia.com>
2023-09-22 3:02 ` Jason Wang
2023-09-22 11:23 ` Michael S. Tsirkin
2023-09-22 3:01 ` Jason Wang
[not found] ` <20230922121132.GK13733@nvidia.com>
2023-09-25 2:34 ` Jason Wang
[not found] ` <20230925122607.GW13733@nvidia.com>
2023-09-25 19:44 ` Michael S. Tsirkin
[not found] ` <20230926004059.GM13733@nvidia.com>
2023-09-26 5:34 ` Michael S. Tsirkin
2023-09-26 5:42 ` Michael S. Tsirkin
[not found] ` <20230926135057.GO13733@nvidia.com>
2023-09-27 21:38 ` Michael S. Tsirkin
[not found] ` <20230927232005.GE339126@nvidia.com>
2023-09-28 5:31 ` Michael S. Tsirkin
2023-09-26 4:37 ` Jason Wang
2023-09-26 5:33 ` Parav Pandit via Virtualization
2023-09-21 19:17 ` Michael S. Tsirkin
[not found] ` <20230921195115.GY13733@nvidia.com>
2023-09-21 20:55 ` Michael S. Tsirkin
2023-09-25 4:44 ` Zhu, Lingshan
2023-09-22 3:45 ` Zhu, Lingshan
2023-09-21 13:33 ` Michael S. Tsirkin
2023-09-21 16:43 ` Alex Williamson
[not found] ` <20230921165224.GR13733@nvidia.com>
2023-09-21 17:01 ` Michael S. Tsirkin
2023-09-21 17:09 ` Parav Pandit via Virtualization
2023-09-21 17:24 ` Michael S. Tsirkin
[not found] ` <20230921170709.GS13733@nvidia.com>
2023-09-21 17:21 ` Michael S. Tsirkin
[not found] ` <20230921174450.GT13733@nvidia.com>
2023-09-21 17:55 ` Michael S. Tsirkin
[not found] ` <20230921181637.GU13733@nvidia.com>
2023-09-21 19:34 ` Michael S. Tsirkin
[not found] ` <20230921195345.GZ13733@nvidia.com>
2023-09-21 20:16 ` Michael S. Tsirkin [this message]
2023-09-22 3:02 ` Jason Wang
[not found] ` <20230922122246.GN13733@nvidia.com>
2023-09-22 12:25 ` Parav Pandit via Virtualization
2023-09-22 15:13 ` Michael S. Tsirkin
[not found] ` <20230922151534.GR13733@nvidia.com>
2023-09-22 15:40 ` Michael S. Tsirkin
[not found] ` <20230922162233.GT13733@nvidia.com>
2023-09-25 17:36 ` Michael S. Tsirkin
2023-09-25 2:30 ` Jason Wang
2023-09-25 8:26 ` Parav Pandit via Virtualization
2023-09-25 18:36 ` Michael S. Tsirkin
2023-09-26 2:34 ` Zhu, Lingshan
2023-09-26 3:45 ` Parav Pandit via Virtualization
2023-09-26 4:37 ` Jason Wang
2023-10-12 10:52 ` Michael S. Tsirkin
2023-10-12 11:11 ` Parav Pandit via Virtualization
2023-10-12 11:30 ` Michael S. Tsirkin
2023-10-12 11:40 ` Parav Pandit via Virtualization
2023-09-26 2:32 ` Jason Wang
2023-09-26 4:01 ` Parav Pandit via Virtualization
2023-09-26 4:37 ` Jason Wang
2023-09-26 5:27 ` Parav Pandit via Virtualization
2023-09-26 11:49 ` Michael S. Tsirkin
2023-10-08 4:28 ` Jason Wang
[not found] ` <20230921224836.GD13733@nvidia.com>
2023-09-22 9:47 ` Michael S. Tsirkin
[not found] ` <20230922122328.GO13733@nvidia.com>
2023-09-22 15:45 ` Michael S. Tsirkin
2023-09-22 3:02 ` Jason Wang
[not found] ` <20230922122501.GP13733@nvidia.com>
2023-09-22 15:39 ` Michael S. Tsirkin
[not found] ` <20230922161928.GS13733@nvidia.com>
2023-09-25 18:16 ` Michael S. Tsirkin
[not found] ` <20230925185318.GK13733@nvidia.com>
2023-09-25 19:52 ` Michael S. Tsirkin
2023-09-21 19:58 ` Alex Williamson
[not found] ` <20230921200121.GA13733@nvidia.com>
2023-09-21 20:20 ` Michael S. Tsirkin
2023-09-21 20:59 ` Alex Williamson
[not found] ` <20230922123708.GA130749@nvidia.com>
2023-09-22 12:59 ` Parav Pandit via Virtualization
2023-09-26 15:20 ` Yishai Hadas via Virtualization
2023-09-26 17:00 ` Michael S. Tsirkin
2023-10-02 4:38 ` Parav Pandit via Virtualization
2023-09-22 10:10 ` Michael S. Tsirkin
2023-09-22 15:53 ` Michael S. Tsirkin
2023-10-02 11:23 ` Parav Pandit via Virtualization
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