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

[Leon Romanovsky]

On Fri, Jul 05, 2024 at 10:53:06PM +0000, Chaitanya Kulkarni wrote:
> On 7/3/24 07:35, Christoph Hellwig wrote:
> > 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
> >
> 
> I tried to reproduce this issue somehow it is not reproducible.
> 
> I'll try again on Leon's setup on my Saturday night, to fix that
> case.

Chaitanya,

I added "mem_align=120" line to fio configuration file and the issue reproduced.

Thanks

> 
> -ck
> 
> 
>