Re: pci_enable_msix() fails with ENOMEM/EINVAL

[Alex Williamson <alex.williamson@redhat.com>]

On Thu, 2012-11-29 at 10:42 +0200, Alex Lyakas wrote:
> Hi Alex,
> did I understand correctly that "vector" value with which the call to 
> request_threaded_irq() is made is *not* supposed to be zero? Because in my 
> case, it is always zero, and still the failure I observe is not happening 
> always. Usually, 3 unique (non-zero) IRQ numbers are assigned to each 
> attached PCI device of each KVM VM.
> I will try to repro this like you suggested and let you know.

pci_enable_msix should be setting vectors for all the host_msix_entries.
That non-zero vector is the first parameter to request_threaded_irq.  If
I put a printk in the loop installing the interrupt handler, I get:

assigned_device_enable_host_msix entry 0, vector 44
assigned_device_enable_host_msix entry 0, vector 44
assigned_device_enable_host_msix entry 1, vector 45
assigned_device_enable_host_msix entry 0, vector 44
assigned_device_enable_host_msix entry 1, vector 45
assigned_device_enable_host_msix entry 2, vector 103

So we enable MSI-X with only one vector enabled, then a second vector
gets enabled and we disable and re-enable with two, and so on with
three.  This is for an assigned e1000e device.  Thanks,

Alex