[RFC PATCH v1 00/18] Provide a new two step DMA API mapping API

[Christoph Hellwig]

On Wed, Jul 03, 2024 at 01:52:53PM +0300, Leon Romanovsky wrote:
> On Wed, Jul 03, 2024 at 07:42:38AM +0200, Christoph Hellwig wrote:
> > I just tried to boot this on my usual qemu test setup with emulated
> > nvme devices, and it dead-loops with messages like this fairly late
> > in the boot cycle:
> > 
> > [   43.826627] iommu: unaligned: iova 0xfff7e000 pa 0x000000010be33650 size 0x1000 min_pagesz 0x1000
> > [   43.826982] dma_mapping_error -12
> > 
> > passing intel_iommu=off instead of intel_iommu=on (expectedly) makes
> > it go away.
> 
> Can you please share your kernel command line and qemu?
> On my and Chaitanya setups it works fine.

qemu-system-x86_64 \
        -nographic \
	-enable-kvm \
	-m 6g \
	-smp 4 \
	-cpu host \
	-M q35,kernel-irqchip=split \
	-kernel arch/x86/boot/bzImage \
	-append "root=/dev/vda console=ttyS0,115200n8 intel_iommu=on" \
        -device intel-iommu,intremap=on \
	-device ioh3420,multifunction=on,bus=pcie.0,id=port9-0,addr=9.0,chassis=0 \	
        -blockdev driver=file,cache.direct=on,node-name=root,filename=/home/hch/images/bookworm.img \
	-blockdev driver=host_device,cache.direct=on,node-name=test,filename=/dev/nvme0n1p4 \
	-device virtio-blk,drive=root \
	-device nvme,drive=test,serial=1234