From: Christoph Hellwig <hch@lst.de>
To: Auger Eric <eric.auger@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>,
Robin Murphy <robin.murphy@arm.com>,
eric.auger.pro@gmail.com, m.szyprowski@samsung.com,
mst@redhat.com, jasowang@redhat.com,
virtualization@lists.linux-foundation.org,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call
Date: Thu, 25 Jul 2019 15:04:16 +0200 [thread overview]
Message-ID: <20190725130416.GA4992@lst.de> (raw)
In-Reply-To: <fa0fbad5-9b44-d937-e0fd-65fb20c90666@redhat.com>
On Thu, Jul 25, 2019 at 01:53:49PM +0200, Auger Eric wrote:
> I am confused: if vring_use_dma_api() returns false if the dma_mask is
> unset (ie. vring_use_dma_api() returns false), the virtio-blk-pci device
> will not be able to get translated addresses and won't work properly.
>
> The patch above allows the dma api to be used and only influences the
> max_segment_size and it works properly.
>
> So is it normal the dma_mask is unset in my case?
Its not normal. I assume you use virtio-nmio? Due to the mess with
the dma_mask being a pointer a lot of subsystems forgot to set a dma
mask up, and oddly enough seem to mostly get away with it.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Auger Eric <eric.auger@redhat.com>
Cc: mst@redhat.com, jasowang@redhat.com,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
iommu@lists.linux-foundation.org, eric.auger.pro@gmail.com,
Robin Murphy <robin.murphy@arm.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call
Date: Thu, 25 Jul 2019 15:04:16 +0200 [thread overview]
Message-ID: <20190725130416.GA4992@lst.de> (raw)
In-Reply-To: <fa0fbad5-9b44-d937-e0fd-65fb20c90666@redhat.com>
On Thu, Jul 25, 2019 at 01:53:49PM +0200, Auger Eric wrote:
> I am confused: if vring_use_dma_api() returns false if the dma_mask is
> unset (ie. vring_use_dma_api() returns false), the virtio-blk-pci device
> will not be able to get translated addresses and won't work properly.
>
> The patch above allows the dma api to be used and only influences the
> max_segment_size and it works properly.
>
> So is it normal the dma_mask is unset in my case?
Its not normal. I assume you use virtio-nmio? Due to the mess with
the dma_mask being a pointer a lot of subsystems forgot to set a dma
mask up, and oddly enough seem to mostly get away with it.
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iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2019-07-25 13:04 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-22 14:55 [PATCH 0/2] Fix NULL pointer dereference with virtio-blk-pci and virtual IOMMU Eric Auger
2019-07-22 14:55 ` Eric Auger
2019-07-22 14:55 ` [PATCH 1/2] dma-mapping: Protect dma_addressing_limited against NULL dma_mask Eric Auger
2019-07-22 14:55 ` Eric Auger
2019-07-22 15:26 ` Christoph Hellwig
2019-07-22 15:26 ` Christoph Hellwig
2019-07-22 15:46 ` Auger Eric
2019-07-22 15:46 ` Auger Eric
2019-07-22 15:46 ` Auger Eric
2019-07-22 15:26 ` Christoph Hellwig
2019-07-22 14:55 ` Eric Auger
2019-07-22 14:55 ` [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call Eric Auger
2019-07-22 14:55 ` Eric Auger
2019-07-22 14:55 ` Eric Auger
2019-07-22 15:27 ` Christoph Hellwig
2019-07-22 15:27 ` Christoph Hellwig
2019-07-22 15:39 ` Michael S. Tsirkin
2019-07-22 15:39 ` Michael S. Tsirkin
2019-07-22 15:39 ` Michael S. Tsirkin
2019-07-22 15:27 ` Christoph Hellwig
2019-07-22 15:33 ` Michael S. Tsirkin
2019-07-22 15:33 ` Michael S. Tsirkin
2019-07-22 15:33 ` Michael S. Tsirkin
2019-07-23 15:38 ` Christoph Hellwig
2019-07-23 15:38 ` Christoph Hellwig
2019-07-23 15:47 ` Michael S. Tsirkin
2019-07-23 15:47 ` Michael S. Tsirkin
2019-07-23 15:47 ` Michael S. Tsirkin
2019-07-23 15:38 ` Christoph Hellwig
2019-07-22 15:36 ` Robin Murphy
2019-07-22 15:36 ` Robin Murphy
2019-07-22 15:36 ` Robin Murphy
2019-07-22 15:45 ` Michael S. Tsirkin
2019-07-22 15:45 ` Michael S. Tsirkin
2019-07-22 15:45 ` Michael S. Tsirkin
2019-07-23 15:38 ` Christoph Hellwig
2019-07-23 15:38 ` Christoph Hellwig
2019-07-23 15:38 ` Christoph Hellwig
2019-07-24 22:10 ` Michael S. Tsirkin
2019-07-24 22:10 ` Michael S. Tsirkin
2019-07-24 22:10 ` Michael S. Tsirkin
2019-07-25 5:25 ` Christoph Hellwig
2019-07-25 5:25 ` Christoph Hellwig
2019-07-25 5:25 ` Christoph Hellwig
2019-07-25 11:53 ` Auger Eric
2019-07-25 11:53 ` Auger Eric
2019-07-25 13:04 ` Christoph Hellwig
2019-07-25 13:04 ` Christoph Hellwig [this message]
2019-07-25 13:04 ` Christoph Hellwig
2019-07-25 16:32 ` Auger Eric
2019-07-25 16:32 ` Auger Eric
2019-07-25 16:32 ` Auger Eric
2019-07-25 11:53 ` Auger Eric
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