Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-25 Thread Auger Eric
Hi Christoph, Michael, On 7/25/19 3:04 PM, Christoph Hellwig wrote: > 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

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-25 Thread Christoph Hellwig
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

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-25 Thread Auger Eric
Hi, On 7/23/19 5:38 PM, Christoph Hellwig wrote: > On Mon, Jul 22, 2019 at 04:36:09PM +0100, Robin Murphy wrote: >>> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c >>> index c8be1c4f5b55..37c143971211 100644 >>> --- a/drivers/virtio/virtio_ring.c >>> +++

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-24 Thread Christoph Hellwig
On Wed, Jul 24, 2019 at 06:10:53PM -0400, Michael S. Tsirkin wrote: > Christoph - would a documented API wrapping dma_mask make sense? > With the documentation explaining how users must > desist from using DMA APIs if that returns false ... We have some bigger changes in this are planned,

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-24 Thread Michael S. Tsirkin
On Tue, Jul 23, 2019 at 05:38:51PM +0200, Christoph Hellwig wrote: > On Mon, Jul 22, 2019 at 04:36:09PM +0100, Robin Murphy wrote: > >> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > >> index c8be1c4f5b55..37c143971211 100644 > >> --- a/drivers/virtio/virtio_ring.c > >>

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-23 Thread Michael S. Tsirkin
On Tue, Jul 23, 2019 at 05:38:30PM +0200, Christoph Hellwig wrote: > On Mon, Jul 22, 2019 at 11:33:35AM -0400, Michael S. Tsirkin wrote: > > On Mon, Jul 22, 2019 at 04:55:09PM +0200, Eric Auger wrote: > > > Do not call dma_max_mapping_size for devices that have no DMA > > > mask set, otherwise we

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-23 Thread Christoph Hellwig
On Mon, Jul 22, 2019 at 04:36:09PM +0100, Robin Murphy wrote: >> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c >> index c8be1c4f5b55..37c143971211 100644 >> --- a/drivers/virtio/virtio_ring.c >> +++ b/drivers/virtio/virtio_ring.c >> @@ -262,7 +262,7 @@ size_t

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-23 Thread Christoph Hellwig
On Mon, Jul 22, 2019 at 11:33:35AM -0400, Michael S. Tsirkin wrote: > On Mon, Jul 22, 2019 at 04:55:09PM +0200, Eric Auger wrote: > > Do not call dma_max_mapping_size for devices that have no DMA > > mask set, otherwise we can hit a NULL pointer dereference. > > > > This occurs when a

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-22 Thread Michael S. Tsirkin
On Mon, Jul 22, 2019 at 04:36:09PM +0100, Robin Murphy wrote: > On 22/07/2019 15:55, Eric Auger wrote: > > Do not call dma_max_mapping_size for devices that have no DMA > > mask set, otherwise we can hit a NULL pointer dereference. > > > > This occurs when a virtio-blk-pci device is protected

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-22 Thread Michael S. Tsirkin
On Mon, Jul 22, 2019 at 05:27:10PM +0200, Christoph Hellwig wrote: > On Mon, Jul 22, 2019 at 04:55:09PM +0200, Eric Auger wrote: > > Do not call dma_max_mapping_size for devices that have no DMA > > mask set, otherwise we can hit a NULL pointer dereference. > > > > This occurs when a

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-22 Thread Robin Murphy
On 22/07/2019 15:55, Eric Auger wrote: Do not call dma_max_mapping_size for devices that have no DMA mask set, otherwise we can hit a NULL pointer dereference. This occurs when a virtio-blk-pci device is protected with a virtual IOMMU. Fixes: e6d6dd6c875e ("virtio: Introduce

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-22 Thread Michael S. Tsirkin
On Mon, Jul 22, 2019 at 04:55:09PM +0200, Eric Auger wrote: > Do not call dma_max_mapping_size for devices that have no DMA > mask set, otherwise we can hit a NULL pointer dereference. > > This occurs when a virtio-blk-pci device is protected with > a virtual IOMMU. > > Fixes: e6d6dd6c875e

Re: [PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-22 Thread Christoph Hellwig
On Mon, Jul 22, 2019 at 04:55:09PM +0200, Eric Auger wrote: > Do not call dma_max_mapping_size for devices that have no DMA > mask set, otherwise we can hit a NULL pointer dereference. > > This occurs when a virtio-blk-pci device is protected with > a virtual IOMMU. > > Fixes: e6d6dd6c875e

[PATCH 2/2] virtio/virtio_ring: Fix the dma_max_mapping_size call

2019-07-22 Thread Eric Auger
Do not call dma_max_mapping_size for devices that have no DMA mask set, otherwise we can hit a NULL pointer dereference. This occurs when a virtio-blk-pci device is protected with a virtual IOMMU. Fixes: e6d6dd6c875e ("virtio: Introduce virtio_max_dma_size()") Signed-off-by: Eric Auger