Re: [PATCH v3 vfio 1/3] pds/vfio: Fix spinlock bad magic BUG

[Brett Creeley <bcreeley@amd.com>]

On 10/30/2023 11:13 PM, Tian, Kevin wrote:
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> 
>> From: Brett Creeley <brett.creeley@amd.com>
>> Sent: Saturday, October 28, 2023 6:37 AM
>>
>> The following BUG was found when running on a kernel with
>> CONFIG_DEBUG_SPINLOCK=y set:
>>
>> BUG: spinlock bad magic on CPU#2, bash/2481
>>   lock: 0xffff8d6052a88f50, .magic: 00000000, .owner: <none>/-1, .owner_cpu:
>> 0
>> Call Trace:
>>   <TASK>
>>   dump_stack_lvl+0x36/0x50
>>   do_raw_spin_lock+0x79/0xc0
>>   pds_vfio_reset+0x1d/0x60 [pds_vfio_pci]
>>   pci_reset_function+0x4b/0x70
>>   reset_store+0x5b/0xa0
>>   kernfs_fop_write_iter+0x137/0x1d0
>>   vfs_write+0x2de/0x410
>>   ksys_write+0x5d/0xd0
>>   do_syscall_64+0x3b/0x90
>>   entry_SYSCALL_64_after_hwframe+0x6e/0xd8
>>
>> As shown, the .magic: 00000000, does not match the expected value. This
>> is because spin_lock_init() is never called for the reset_lock. Fix
>> this by calling spin_lock_init(&pds_vfio->reset_lock) when initializing
>> the device.
>>
>> Signed-off-by: Brett Creeley <brett.creeley@amd.com>
>> Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
> 
> is this patch still required with patch3?

Good point. It's not required anymore since there is no spinlock.

Thanks,

Brett