From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: shahafs@mellanox.com, lulu@redhat.com, saugatm@xilinx.com,
mhabets@solarflare.com, vmireyno@marvell.com,
linux-kernel@vger.kernel.org, gdawar@xilinx.com,
virtualization@lists.linux-foundation.org, eperezma@redhat.com,
hanand@xilinx.com, zhangweining@ruijie.com.cn, eli@mellanox.com,
lingshan.zhu@intel.com, rob.miller@broadcom.com
Subject: Re: [PATCH 3/4] vdpa: get_iova_range() is mandatory for device specific DMA translation
Date: Wed, 5 Aug 2020 08:55:27 -0400 [thread overview]
Message-ID: <20200805085217-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20200617032947.6371-4-jasowang@redhat.com>
On Wed, Jun 17, 2020 at 11:29:46AM +0800, Jason Wang wrote:
> In order to let userspace work correctly, get_iova_range() is a must
> for the device that has its own DMA translation logic.
I guess you mean for a device.
However in absence of ths op, I don't see what is wrong with just
assuming device can access any address.
>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> drivers/vdpa/vdpa.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> index de211ef3738c..ab7af978ef70 100644
> --- a/drivers/vdpa/vdpa.c
> +++ b/drivers/vdpa/vdpa.c
> @@ -82,6 +82,10 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
> if (!!config->dma_map != !!config->dma_unmap)
> goto err;
>
> + if ((config->dma_map || config->set_map) &&
> + !config->get_iova_range)
> + goto err;
> +
> err = -ENOMEM;
> vdev = kzalloc(size, GFP_KERNEL);
> if (!vdev)
What about devices using an IOMMU for translation?
IOMMUs generally have a limited IOVA range too, right?
> --
> 2.20.1
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next prev parent reply other threads:[~2020-08-05 12:55 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 3:29 [PATCH 0/4] vDPA: API for reporting IOVA range Jason Wang
2020-06-17 3:29 ` [PATCH 1/4] vdpa: introduce config op to get valid iova range Jason Wang
2020-08-05 12:51 ` Michael S. Tsirkin
2020-08-06 3:25 ` Jason Wang
2020-08-06 5:54 ` Michael S. Tsirkin
[not found] ` <20200806120354.GA171218@mtl-vdi-166.wap.labs.mlnx>
2020-08-06 12:29 ` Michael S. Tsirkin
2020-08-07 3:23 ` Jason Wang
[not found] ` <20200806124354.GA172661@mtl-vdi-166.wap.labs.mlnx>
2020-08-10 12:05 ` Michael S. Tsirkin
2020-08-11 2:53 ` Jason Wang
2020-08-11 8:29 ` Michael S. Tsirkin
2020-08-12 2:02 ` Jason Wang
[not found] ` <20200806121002.GA171574@mtl-vdi-166.wap.labs.mlnx>
2020-08-07 3:04 ` Jason Wang
2020-06-17 3:29 ` [PATCH 2/4] vdpa_sim: implement get_iova_range bus operation Jason Wang
2020-06-17 3:29 ` [PATCH 3/4] vdpa: get_iova_range() is mandatory for device specific DMA translation Jason Wang
2020-08-05 12:55 ` Michael S. Tsirkin [this message]
2020-08-06 3:27 ` Jason Wang
2020-06-17 3:29 ` [PATCH 4/4] vhost: vdpa: report iova range Jason Wang
2020-08-05 12:58 ` Michael S. Tsirkin
2020-08-06 3:29 ` Jason Wang
2020-08-06 5:55 ` Michael S. Tsirkin
2020-10-21 14:45 ` [PATCH 0/4] vDPA: API for reporting IOVA range Michael S. Tsirkin
2020-10-22 5:47 ` Jason Wang
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