[libvirt] [PATCH v2 3/9] hostdev: Use common reattach code in virHostdevPCINodeDeviceReAttach()

[John Ferlan]

On 01/25/2016 11:20 AM, Andrea Bolognani wrote:
> This ensures the behavior for reattach is consistent, no matter how it
> was triggered (eg. 'virsh nodedev-reattach', 'virsh detach-device' or
> shutdown of a domain that is configured to use hostdevs).

Similar to 2/9 - using virHostdevOnlyReattachPCIDevice will result in a
call to virPCIDeviceGetStubDriver and virPCIDeviceWaitForCleanup - for
this path I assume this is thus desired.

> ---
>  src/util/virhostdev.c | 33 ++++++++++++++++++++++++++++++---
>  1 file changed, 30 insertions(+), 3 deletions(-)
> 
> diff --git a/src/util/virhostdev.c b/src/util/virhostdev.c
> index 586937e..f40d636 100644
> --- a/src/util/virhostdev.c
> +++ b/src/util/virhostdev.c
> @@ -1637,10 +1637,24 @@ virHostdevPCINodeDeviceDetach(virHostdevManagerPtr hostdev_mgr,
>      return ret;
>  }
>  
> +/**
> + * virHostdevPCINodeDeviceReAttach:

^^ Oy ReAttach vs. Reattach is an eye test ;-)

> + * @hostdev_mgr: hostdev manager
> + * @pci: PCI device

Perhaps better to indicate a "new"ly generated PCI device that does not
track the internal reattach states and other state information such as
the stub driver.

IOW: this is not a copy of an [in]activePCIHostdevs element

> + *
> + * Reattach a specific PCI device to the host.
> + *
> + * This function makes sure the device is not in use before reattaching it
> + * to the host; if the device has already been reattached to the host, the
> + * operation is considered successful.
> + *
> + * Returns: 0 on success, <0 on failure
> + */
>  int
>  virHostdevPCINodeDeviceReAttach(virHostdevManagerPtr hostdev_mgr,
>                                  virPCIDevicePtr pci)
>  {
> +    virPCIDevicePtr actual;
>      struct virHostdevIsPCINodeDeviceUsedData data = {hostdev_mgr, NULL,
>                                                       false};
>      int ret = -1;
> @@ -1651,10 +1665,23 @@ virHostdevPCINodeDeviceReAttach(virHostdevManagerPtr hostdev_mgr,
>      if (virHostdevIsPCINodeDeviceUsed(virPCIDeviceGetAddress(pci), &data))
>          goto out;
>  
> -    virPCIDeviceReattachInit(pci);
> +    /* We want this function to be idempotent, so if the device has already
> +     * been removed from the inactive list (and is not active either, as
> +     * per the check above) just return right away. We also need to retrieve
> +     * the actual device from the inactive list because that's the one that
> +     * contains state information such as the stub driver */
> +    if (!(actual = virPCIDeviceListFind(hostdev_mgr->inactivePCIHostdevs,
> +                                        pci))) {

As noted in my 1/9 review - this code path passes the 'actual' dev
onlist... The call we're about to make is going to repeat this search.
Something we could avoid if performance of list searches were a concern.

No other issues -

John
> +        VIR_DEBUG("PCI device %s is already attached to the host",
> +                  virPCIDeviceGetName(pci));
> +        ret = 0;
> +        goto out;
> +    }
>  
> -    if (virPCIDeviceReattach(pci, hostdev_mgr->activePCIHostdevs,
> -                             hostdev_mgr->inactivePCIHostdevs) < 0)
> +    /* Reattach the device. We don't want to skip unmanaged devices in
> +     * this case, because the user explicitly asked for the device to
> +     * be reattached to the host driver */
> +    if (virHostdevOnlyReattachPCIDevice(hostdev_mgr, actual, false) < 0)
>          goto out;
>  
>      ret = 0;
>