From: "hch@infradead.org" <hch@infradead.org>
To: Peng Fan <peng.fan@nxp.com>
Cc: "mst@redhat.com" <mst@redhat.com>,
"jasowang@redhat.com" <jasowang@redhat.com>,
"sstabellini@kernel.org" <sstabellini@kernel.org>,
"hch@infradead.org" <hch@infradead.org>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-remoteproc@vger.kernel.org"
<linux-remoteproc@vger.kernel.org>
Subject: Re: [RFC] virtio_ring: check dma_mem for xen_domain
Date: Mon, 21 Jan 2019 00:28:30 -0800 [thread overview]
Message-ID: <20190121082830.GC12420@infradead.org> (raw)
In-Reply-To: <20190121050056.14325-1-peng.fan@nxp.com>
On Mon, Jan 21, 2019 at 04:51:57AM +0000, Peng Fan wrote:
> on i.MX8QM, M4_1 is communicating with DomU using rpmsg with a fixed
> address as the dma mem buffer which is predefined.
>
> Without this patch, the flow is:
> vring_map_one_sg -> vring_use_dma_api
> -> dma_map_page
> -> __swiotlb_map_page
> ->swiotlb_map_page
> ->__dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
> However we are using per device dma area for rpmsg, phys_to_virt
> could not return a correct virtual address for virtual address in
> vmalloc area. Then kernel panic.
And that is the right thing to do. You must not call dma_map_* on
memory that was allocated from dma_alloc_*.
We actually have another thread which appears to be for this same issue.
next prev parent reply other threads:[~2019-01-21 8:28 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-21 4:51 [RFC] virtio_ring: check dma_mem for xen_domain Peng Fan
2019-01-21 8:28 ` hch [this message]
2019-01-22 2:32 ` Peng Fan
2019-01-22 2:36 ` Michael S. Tsirkin
2019-01-22 19:59 ` [Xen-devel] " Stefano Stabellini
2019-01-23 2:57 ` Michael S. Tsirkin
2019-01-23 7:12 ` hch
2019-01-23 21:04 ` Stefano Stabellini
2019-01-23 21:14 ` hch
2019-01-23 23:43 ` Stefano Stabellini
2019-01-24 6:47 ` Peng Fan
2019-01-24 19:14 ` Stefano Stabellini
2019-01-24 20:34 ` Michael S. Tsirkin
2019-01-25 9:45 ` Peng Fan
2019-01-25 19:18 ` Stefano Stabellini
2019-01-28 8:00 ` hch
2019-01-29 9:26 ` Peng Fan
2019-01-24 6:42 ` Peng Fan
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