Re: Daily Xen Builds

[David F Barrera <dfbp@us.ibm.com>]

Ian Pratt wrote:

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>>>I can't see why creating a domU would be helped by a swiotlb. 
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>>>
>>Without it, dom0 crashes. I reported on Bugzilla #168 a 
>>couple of days ago the following crash when creating a domU 
>>on machines built with PAE:
>>
>>Fatal DMA error! Please use 'swiotlb=force'
>>kernel BUG at arch/xen/i386/kernel/pci-dma.c:30 (iommu_bug)!
>> [<c010ea0b>] iommu_bug+0x3b/0x50
>> [<c010eb6a>] dma_map_sg+0x14a/0x170
>> [<c02f5023>] ide_map_sg+0xa3/0xb0
>> [<c02fe86c>] ide_build_sglist+0x7c/0xd0  [<c02fe8ff>] 
>>ide_build_dmatable+0x3f/0x190  [<c02fedda>] 
>>ide_dma_setup+0x3a/0xe0  [<c0301120>] 
>>__ide_do_rw_disk+0x3d0/0x5a0  [<c02f6f00>] 
>>ide_wait_stat+0+30/0x230  [<c02837fc>] 
>>as_move_to_dispatch+0xec/0x220  [<c02f5550>] 
>>start_request+0x270/0x290  [<c02f581c>] 
>>ide_do_request+0x27c/0x470  [<c027940c>] 
>>elv_next_request+0x3c/0x1b0  [<c02f5a34>] 
>>do_ide_request+0x24/0x30  [<c027c62a>] 
>>generic_unplug_device+0x2a/0x70  [<c027c600>] 
>>generic_unplug_device+0x0/0x70  [<c02e74b6>] 
>>blkio_schedule+0x186/0x190  [<c011e070>] 
>>default_wake_function+0x0/0x20  [<c010a662>] 
>>ret_from_fork+0x6/0x14  [<c011e070>] 
>>default_wake_function+0x0/0x20  [<c02e7330>] 
>>blkio_schedule+0x0/0x190  [<c0108615>] 
>>kernel_thread_helper+0x5/0x10 Kernel panic - not syncing: BUG!
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>>>Precisely which adaptec card is it, what driver?
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>>SCSI storage controller: Adaptec AIC-7901 U320 (rev 10)
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>This backtrace looks like its doing ide transfers. Have you got active
>ide devices in this system?
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Actually, the trace was obtained from a machine that has an IDE drive. 
It was one of two that exhibited this behavior (the other has the SCSI 
drive), and the only one where I could capture the console log.

>Also, please can you rerun this test as the debugging output has been
>improved.
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I'll do that as soon as I can get the machine back; it is being used to 
look into another issue at the moment.

>Thanks,
>Ian
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