From: Christoph Hellwig <hch@infradead.org>
To: Jason Wang <jasowang@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
virtualization@lists.linux-foundation.org,
Guenter Roeck <linux@roeck-us.net>,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH vhost v6 08/11] virtio_ring: introduce virtqueue_dma_dev()
Date: Mon, 10 Apr 2023 21:09:55 -0700 [thread overview]
Message-ID: <ZDTdk0K6LO5+0OLA@infradead.org> (raw)
In-Reply-To: <CACGkMEtD0BLBXv7S-TLY-Y483_Lx4UskLyPmEC2wyGa8VE_R6w@mail.gmail.com>
On Tue, Apr 11, 2023 at 11:56:47AM +0800, Jason Wang wrote:
> > The DMA device for virtio_pci is the underlying PCI device, always.
> > !VIRTIO_F_ACCESS_PLATFORM means there is no dma device at all. Because
> > of all these things you can't just expose a pointer to the dma_device
> > as that is just a completely wrong way of thinking about the problem.
>
> Ok, so if there's no DMA at all we should avoid using the DMA API
> completely. This means we should check dma_dev against NULL in
> virtio_has_dma_quirk().
No nee to add a check to virtio_has_dma_quirk.
But looking at virtio_has_dma_quirk shows that virtio-gpu is
pretty messed up already as well.
It can't really poke into the DMA details. We'll need core virtio
helpers for allocating and syncing a sg_table instead and make
virtio_has_dma_quirk private to the core.
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next prev parent reply other threads:[~2023-04-11 4:10 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-27 4:05 [PATCH vhost v6 00/11] virtio core prepares for AF_XDP Xuan Zhuo
2023-03-27 4:05 ` [PATCH vhost v6 01/11] virtio_ring: split: separate dma codes Xuan Zhuo
2023-03-28 6:26 ` Jason Wang
2023-03-27 4:05 ` [PATCH vhost v6 02/11] virtio_ring: packed: " Xuan Zhuo
2023-03-27 4:05 ` [PATCH vhost v6 03/11] virtio_ring: packed-indirect: " Xuan Zhuo
2023-03-27 4:05 ` [PATCH vhost v6 04/11] virtio_ring: split: support premapped Xuan Zhuo
2023-03-28 6:27 ` Jason Wang
2023-03-27 4:05 ` [PATCH vhost v6 05/11] virtio_ring: packed: " Xuan Zhuo
2023-03-28 6:27 ` Jason Wang
2023-03-27 4:05 ` [PATCH vhost v6 06/11] virtio_ring: packed-indirect: " Xuan Zhuo
2023-03-28 6:29 ` Jason Wang
2023-03-27 4:05 ` [PATCH vhost v6 07/11] virtio_ring: update document for virtqueue_add_* Xuan Zhuo
2023-03-28 6:30 ` Jason Wang
2023-03-27 4:05 ` [PATCH vhost v6 08/11] virtio_ring: introduce virtqueue_dma_dev() Xuan Zhuo
2023-04-06 17:20 ` Guenter Roeck
2023-04-07 3:17 ` Xuan Zhuo
2023-04-07 12:34 ` Guenter Roeck
2023-04-07 11:02 ` Michael S. Tsirkin
2023-04-10 3:29 ` Xuan Zhuo
2023-04-10 5:14 ` Jason Wang
2023-04-10 6:03 ` Xuan Zhuo
2023-04-10 6:40 ` Michael S. Tsirkin
2023-04-10 6:42 ` Xuan Zhuo
2023-04-10 15:27 ` Christoph Hellwig
2023-04-11 1:56 ` Xuan Zhuo
2023-04-11 2:09 ` Jason Wang
2023-04-11 3:31 ` Christoph Hellwig
2023-04-11 3:56 ` Jason Wang
2023-04-11 4:09 ` Christoph Hellwig [this message]
2023-04-11 4:54 ` Jason Wang
2023-04-11 5:14 ` Christoph Hellwig
2023-04-11 5:19 ` Jason Wang
2023-04-11 8:55 ` Gerd Hoffmann
2023-04-11 6:11 ` Xuan Zhuo
2023-04-11 6:20 ` Christoph Hellwig
2023-04-11 6:28 ` Xuan Zhuo
2023-04-11 6:46 ` Christoph Hellwig
2023-04-11 6:51 ` Xuan Zhuo
2023-04-11 7:04 ` Xuan Zhuo
2023-04-12 2:03 ` Xuan Zhuo
2023-04-12 11:54 ` Christoph Hellwig
2023-04-11 3:26 ` Christoph Hellwig
2023-04-11 6:23 ` Xuan Zhuo
2023-04-11 6:30 ` Christoph Hellwig
2023-04-11 6:33 ` Xuan Zhuo
2023-04-11 6:45 ` Christoph Hellwig
2023-04-11 7:23 ` Xuan Zhuo
2023-04-11 12:16 ` Christoph Hellwig
2023-04-18 6:18 ` Xuan Zhuo
2023-04-19 5:10 ` Christoph Hellwig
2023-04-19 6:16 ` Xuan Zhuo
2023-04-11 7:12 ` Xuan Zhuo
2023-04-11 8:59 ` Jason Wang
2023-04-11 12:17 ` Christoph Hellwig
2023-03-27 4:05 ` [PATCH vhost v6 09/11] virtio_ring: correct the expression of the description of virtqueue_resize() Xuan Zhuo
2023-03-27 4:05 ` [PATCH vhost v6 10/11] virtio_ring: separate the logic of reset/enable from virtqueue_resize Xuan Zhuo
2023-03-27 4:05 ` [PATCH vhost v6 11/11] virtio_ring: introduce virtqueue_reset() Xuan Zhuo
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