similar to: [PATCH v7 0/5] Fix virtio-blk issue with SWIOTLB

Both split ring and packed ring use 32bits to describe the length of a descriptor: see struct vring_desc and struct vring_packed_desc. This means the max segment size supported by virtio is U32_MAX. An example of virtio_max_dma_size in virtio_blk.c: u32 v, max_size; max_size = virtio_max_dma_size(vdev); -> implicit convert err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,

On Wed, 10 May 2023 10:54:37 +0800, zhenwei pi <pizhenwei at bytedance.com> wrote: > Both split ring and packed ring use 32bits to describe the length of > a descriptor: see struct vring_desc and struct vring_packed_desc. > This means the max segment size supported by virtio is U32_MAX. > > An example of virtio_max_dma_size in virtio_blk.c: > u32 v, max_size; > >

On Thu, Jan 31, 2019 at 05:33:58PM +0100, Joerg Roedel wrote: > Hi, > > here is the next version of this patch-set. Previous > versions can be found here: > > V1: https://lore.kernel.org/lkml/20190110134433.15672-1-joro at 8bytes.org/ > > V2: https://lore.kernel.org/lkml/20190115132257.6426-1-joro at 8bytes.org/ > > V3:

On Thu, Jan 31, 2019 at 05:33:58PM +0100, Joerg Roedel wrote: > Hi, > > here is the next version of this patch-set. Previous > versions can be found here: > > V1: https://lore.kernel.org/lkml/20190110134433.15672-1-joro at 8bytes.org/ > > V2: https://lore.kernel.org/lkml/20190115132257.6426-1-joro at 8bytes.org/ > > V3:

On Wed, May 10, 2023 at 10:54:37AM +0800, zhenwei pi wrote: > Both split ring and packed ring use 32bits to describe the length of > a descriptor: see struct vring_desc and struct vring_packed_desc. > This means the max segment size supported by virtio is U32_MAX. > > An example of virtio_max_dma_size in virtio_blk.c: > u32 v, max_size; > > max_size =

On Wed, May 10, 2023 at 10:54:37AM +0800, zhenwei pi wrote: > Both split ring and packed ring use 32bits to describe the length of > a descriptor: see struct vring_desc and struct vring_packed_desc. > This means the max segment size supported by virtio is U32_MAX. > > An example of virtio_max_dma_size in virtio_blk.c: > u32 v, max_size; > > max_size =

On Wed, May 10, 2023 at 11:26:54AM +0800, Xuan Zhuo wrote: > On Wed, 10 May 2023 10:54:37 +0800, zhenwei pi <pizhenwei at bytedance.com> wrote: > > Both split ring and packed ring use 32bits to describe the length of > > a descriptor: see struct vring_desc and struct vring_packed_desc. > > This means the max segment size supported by virtio is U32_MAX. > > >

On Wed, May 10, 2023 at 11:44?AM Michael S. Tsirkin <mst at redhat.com> wrote: > > On Wed, May 10, 2023 at 11:26:54AM +0800, Xuan Zhuo wrote: > > On Wed, 10 May 2023 10:54:37 +0800, zhenwei pi <pizhenwei at bytedance.com> wrote: > > > Both split ring and packed ring use 32bits to describe the length of > > > a descriptor: see struct vring_desc and struct

When running a guest featuring a virtio-blk-pci protected with a virtual IOMMU we hit a NULL pointer dereference. This series removes the dma_max_mapping_size() call in virtio_max_dma_size when the device does not have any dma_mask set. A check is also added to early return in dma_addressing_limited() if the dma_mask is NULL. Eric Auger (2): dma-mapping: Protect dma_addressing_limited against

tree: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next head: 104f89a60ef5ec77d6f559eac4676844b3480740 commit: 155fcd8511de5f99c27a726e9153b87cce528b6e [3/23] swiotlb: Add is_swiotlb_active() function config: i386-tinyconfig (attached as .config) compiler: gcc-8 (Debian 8.2.0-14) 8.2.0 reproduce: git checkout 155fcd8511de5f99c27a726e9153b87cce528b6e #

From: Joerg Roedel <jroedel at suse.de> The function returns the maximum size that can be mapped using DMA-API functions. The patch also adds the implementation for direct DMA and a new dma_map_ops pointer so that other implementations can expose their limit. Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com> Reviewed-by: Christoph Hellwig <hch at lst.de>

We must make sure our scatterlist segments are not too big, otherwise we might see swiotlb failures (happens with sev, also reproducable with swiotlb=force). Signed-off-by: Gerd Hoffmann <kraxel at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_object.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c

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 ("virtio: Introduce virtio_max_dma_size()") > Signed-off-by: Eric Auger

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 ("virtio: Introduce virtio_max_dma_size()") > Signed-off-by: Eric Auger

Hi all, this little series removes the last swiotlb API exposed to modules. Diffstat: arch/x86/include/asm/xen/swiotlb-xen.h | 6 ------ arch/x86/kernel/pci-dma.c | 28 ++++------------------------ drivers/gpu/drm/nouveau/nouveau_ttm.c | 10 +++------- drivers/pci/xen-pcifront.c | 6 ------ kernel/dma/swiotlb.c | 1 - 5 files changed, 7

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 virtio_max_dma_size()") > Signed-off-by: Eric Auger <eric.auger at

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 virtio_max_dma_size()") > Signed-off-by: Eric Auger <eric.auger at

From: Joerg Roedel <jroedel at suse.de> This function will be used from dma_direct code to determine the maximum segment size of a dma mapping. Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com> Reviewed-by: Christoph Hellwig <hch at lst.de> Signed-off-by: Joerg Roedel <jroedel at suse.de> --- include/linux/swiotlb.h | 6 ++++++ kernel/dma/swiotlb.c | 9

The following changes since commit 1c163f4c7b3f621efff9b28a47abb36f7378d783: Linux 5.0 (2019-03-03 15:21:29 -0800) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git tags/for_linus for you to fetch changes up to cfdbb4ed31aa777d59b288810f66eb06249ee5b7: vhost: silence an unused-variable warning (2019-03-06 11:32:37 -0500)

Drivers have no business looking into dma-mapping internals and check what backend is used. Unfortunstely the DRM core is still broken and tries to do plain page allocations instead of using DMA API allocators by default and uses various bandaids on when to use dma_alloc_coherent. Switch nouveau to use the same (broken) scheme as amdgpu and radeon to remove the last driver user of