From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Lan, Tianyu" <tianyu.lan@intel.com>
Subject: Re: [RFC PATCH V2 09/10] Qemu/VFIO: Add SRIOV VF migration support
Date: Wed, 25 Nov 2015 23:32:23 +0800
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To: "Michael S. Tsirkin" <mst@redhat.com>
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On 11/25/2015 5:03 AM, Michael S. Tsirkin wrote:
>> >+void vfio_migration_cap_handle(PCIDevice *pdev, uint32_t addr,
>> >+                                  uint32_t val, int len)
>> >+{
>> >+    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
>> >+
>> >+    if (addr == vdev->migration_cap + PCI_VF_MIGRATION_VF_STATUS
>> >+        && val == PCI_VF_READY_FOR_MIGRATION) {
>> >+        qemu_event_set(&migration_event);
> This would wake migration so it can proceed -
> except it needs QEMU lock to run, and that's
> taken by the migration thread.

Sorry, I seem to miss something.
Which lock may cause dead lock when calling vfio_migration_cap_handle()
and run migration?
The function is called when VF accesses faked PCI capability.

>
> It seems unlikely that this ever worked - how
> did you test this?
>