Re: [Qemu-devel] [PATCH v2 2/2] ivshmem: use irqfd to interrupt among VMs

[Cam Macdonell]

On Wed, Dec 5, 2012 at 1:50 AM, Jan Kiszka <address@hidden> wrote:
> On 2012-12-05 06:34, Cam Macdonell wrote:
>>>  static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
>>>                                  uint32_t val, int len)
>>>  {
>>> +    bool is_enabled, was_enabled = msi_enabled(pci_dev);
>>> +
>>>      pci_default_write_config(pci_dev, address, val, len);
>>> +    is_enabled = msi_enabled(pci_dev);
>>
>> Problem 1)  in my tests is_enabled is always 0, so I don't think the
>> irqfds are getting setup
>
> You likely want to call msix_enabled here.

Yup, that gets it working.

Liu Ping, can you update the patch to use msix_enabled()?

Also, it seems that with irqfd enabled the user-level handlers are not
triggered, but it may still be a better idea to not add the user-level
handlers to the char devices at all if irqfd is enabled.

Cam

>
> Jan
>
> --
> Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
> Corporate Competence Center Embedded Linux
>