On Mon, 2022-10-24 at 17:26 +0530, Sreekanth Reddy wrote:
On Sun, Oct 23, 2022 at 6:57 AM Bart Van Assche <bvanassche@xxxxxxx>
wrote:
On 10/21/22 02:22, Salvatore Bonaccorso wrote:
We got the following report in Debian after an update from
5.10.140 to
the current 5.10.149. Full quoting below (from
https://bugs.debian.org/1022126). Does this ring some bell about
known
regressions?
Only three mpt3sas changes are new in v5.10.149 compared to
v5.10.140:
$ git log --format=oneline v5.10.140..v5.10.149
2b9aba0c5d58e141e32bb1bb4c7cd91d19f075b8 scsi: mpt3sas: Fix return
value check of dma_get_required_mask()
e7fafef9830c4a01e60f76e3860a9bef0262378d scsi: mpt3sas: Force PCIe
scatterlist allocations to be within same 4 GB region
ea10a652ad2ae2cf3eced6f632a5c98f26727057 scsi: mpt3sas: Fix use-
after-free warning
Sreekanth and Suganath, can you help with bisecting this issue? For
the
full report, see also
https://lore.kernel.org/linux-scsi/Y1JkuKTjVYrOWbvm@xxxxxxxxxxx/.
This issue is getting observed after having the below patch changes,
2b9aba0c5d58e141e32bb1bb4c7cd91d19f075b8 scsi: mpt3sas: Fix return
value check of dma_get_required_mask()
What is happening is that on Xen hypervisor, this
dma_get_required_mask() API always returns a 32 bit DMA mask. I.e. It
says that the minimum DMA mask required to access the host memory is
32 bit and hence mpt3sas driver is setting the DMA mask to 32bit.
This sounds entirely correct because the VM is booted with (from the
original debian bug report):
dom0_mem=4096M,max:4096M dom0_max_vcpus=4 dom0_vcpus_pin
ucode=scan xpti=dom0=false,domu=true gnttab_max_frames=128
So it has no memory above 4GB and thus 32 bit addressing is the minimum
required. If you boot a machine with >4GB and Xen still returns a 32
bit mask here, then we have a Xen problem.
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