Bug#1022126: mpt3sas broken with xen dom0
to be a bit more precise (sorry for being a bit sloopy). we don't see
same error with `swiotlb buffer` but rather
```
mpt3sas_cm0: failure at
drivers/scsi/mpt3sasg/mpt3sas_scsih.c:11069/_scsih_probe()!
```
as reported in `1023183@bugs.debian.org`
```
# dmesg | grep mpt
[ 0.233229] Normal empty
[ 0.233231] Device empty
[ 0.642600] MDS: Vulnerable: Clear CPU buffers attempted, no microcode
[ 0.642676] TAA: Vulnerable: Clear CPU buffers attempted, no microcode
[ 0.642752] MMIO Stale Data: Vulnerable: Clear CPU buffers attempted,
no microcode
[ 3.243654] mpt3sas version 35.100.00.00 loaded
[ 3.244357] mpt3sas_cm0: 32 BIT PCI BUS DMA ADDRESSING SUPPORTED,
total mem (917052 kB)
[ 3.302439] mpt3sas_cm0: CurrentHostPageSize is 0: Setting default
host page size to 4k
[ 3.302575] mpt3sas_cm0: MSI-X vectors supported: 96
[ 3.302733] mpt3sas_cm0: 0 40
[ 3.308666] mpt3sas_cm0: High IOPs queues : disabled
[ 3.308747] mpt3sas0-msix0: PCI-MSI-X enabled: IRQ 396
[ 3.308826] mpt3sas0-msix1: PCI-MSI-X enabled: IRQ 397
[ 3.308905] mpt3sas0-msix2: PCI-MSI-X enabled: IRQ 398
[ 3.308983] mpt3sas0-msix3: PCI-MSI-X enabled: IRQ 399
[ 3.309062] mpt3sas0-msix4: PCI-MSI-X enabled: IRQ 400
[ 3.309141] mpt3sas0-msix5: PCI-MSI-X enabled: IRQ 401
[ 3.309221] mpt3sas0-msix6: PCI-MSI-X enabled: IRQ 402
[ 3.309224] mpt3sas0-msix7: PCI-MSI-X enabled: IRQ 403
[ 3.309466] mpt3sas0-msix8: PCI-MSI-X enabled: IRQ 404
[ 3.309544] mpt3sas0-msix9: PCI-MSI-X enabled: IRQ 405
[ 3.309623] mpt3sas0-msix10: PCI-MSI-X enabled: IRQ 406
[ 3.309703] mpt3sas0-msix11: PCI-MSI-X enabled: IRQ 407
[ 3.309706] mpt3sas0-msix12: PCI-MSI-X enabled: IRQ 408
[ 3.309945] mpt3sas0-msix13: PCI-MSI-X enabled: IRQ 409
[ 3.310024] mpt3sas0-msix14: PCI-MSI-X enabled: IRQ 410
[ 3.310104] mpt3sas0-msix15: PCI-MSI-X enabled: IRQ 411
[ 3.310183] mpt3sas0-msix16: PCI-MSI-X enabled: IRQ 412
[ 3.310186] mpt3sas0-msix17: PCI-MSI-X enabled: IRQ 413
[ 3.310427] mpt3sas0-msix18: PCI-MSI-X enabled: IRQ 414
[ 3.310506] mpt3sas0-msix19: PCI-MSI-X enabled: IRQ 415
[ 3.310585] mpt3sas0-msix20: PCI-MSI-X enabled: IRQ 416
[ 3.310588] mpt3sas0-msix21: PCI-MSI-X enabled: IRQ 417
[ 3.310827] mpt3sas0-msix22: PCI-MSI-X enabled: IRQ 418
[ 3.310906] mpt3sas0-msix23: PCI-MSI-X enabled: IRQ 419
[ 3.310985] mpt3sas0-msix24: PCI-MSI-X enabled: IRQ 420
[ 3.310988] mpt3sas0-msix25: PCI-MSI-X enabled: IRQ 421
[ 3.316842] mpt3sas0-msix26: PCI-MSI-X enabled: IRQ 422
[ 3.316845] mpt3sas0-msix27: PCI-MSI-X enabled: IRQ 423
[ 3.317008] mpt3sas0-msix28: PCI-MSI-X enabled: IRQ 424
[ 3.317011] mpt3sas0-msix29: PCI-MSI-X enabled: IRQ 425
[ 3.317180] mpt3sas0-msix30: PCI-MSI-X enabled: IRQ 426
[ 3.317182] mpt3sas0-msix31: PCI-MSI-X enabled: IRQ 427
[ 3.317384] mpt3sas0-msix32: PCI-MSI-X enabled: IRQ 428
[ 3.317386] mpt3sas0-msix33: PCI-MSI-X enabled: IRQ 429
[ 3.317569] mpt3sas0-msix34: PCI-MSI-X enabled: IRQ 430
[ 3.317572] mpt3sas0-msix35: PCI-MSI-X enabled: IRQ 431
[ 3.317736] mpt3sas0-msix36: PCI-MSI-X enabled: IRQ 432
[ 3.317739] mpt3sas0-msix37: PCI-MSI-X enabled: IRQ 433
[ 3.317929] mpt3sas0-msix38: PCI-MSI-X enabled: IRQ 434
[ 3.317931] mpt3sas0-msix39: PCI-MSI-X enabled: IRQ 435
[ 3.318197] mpt3sas_cm0: iomem(0x00000000ac400000),
mapped(0x00000000a634eda5), size(65536)
[ 3.318200] mpt3sas_cm0: ioport(0x0000000000006000), size(256)
[ 3.378171] mpt3sas_cm0: CurrentHostPageSize is 0: Setting default
host page size to 4k
[ 3.406933] mpt3sas_cm0: scatter gather: sge_in_main_msg(1),
sge_per_chain(7), sge_per_io(128), chains_per_io(19)
[ 3.412485] mpt3sas_cm0: failure at
drivers/scsi/mpt3sasg/mpt3sas_scsih.c:11069/_scsih_probe()!
```
Reply to: