From: Alex Williamson <alex.williamson@redhat.com>
To: Sreekanth Reddy <sreekanth.reddy@avagotech.com>
Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org, konrad.wilk@oracle.com,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Christoph Hellwig <hch@lst.de>,
boris.ostrovsky@oracle.com,
Sathya Prakash <sathya.prakash@avagotech.com>,
Nagalakshmi Nandigama <nagalakshmi.nandigama@avagotech.com>
Subject: Re: How to get the number of VFs assigned to the guests in XEN
Date: Wed, 20 Aug 2014 06:46:11 -0600 [thread overview]
Message-ID: <1408538771.11383.33.camel@ul30vt.home> (raw)
In-Reply-To: <CAK=zhgrv=e20s11v7Ls5ioWZrbyvp9Rzyv+QRDLR3mffr9E61A@mail.gmail.com>
On Wed, 2014-08-20 at 16:39 +0530, Sreekanth Reddy wrote:
> HI,
>
> For SRIOV support, currently in the KVM environment, mpt3sas driver
> can use the API pci_vfs_assigned() to know the number of VFs that are
> currently assigned to the running VMs. So that during the PF driver
> unload time, if the return value of this API is greater than zero the
> our driver won't call the pci_disable_sriov() to disable the VFs.
>
> Now for the same purpose in XEN environment, is there any API similar
> to pci_vfs_assigned() which the low lever device driver can use to
> know 'the number of VFs that are currently assigned to the running
> VMs'. In XEN environment this API pci_vfs_assigned() will return
> always zero even though VFs are assigned to the running VMs.
Note that pci_vfs_assigned() assigned is only used by legacy KVM device
assignment and primarily as a workaround for not using an actual
host-based device driver to manage device ownership. When using
VFIO-based device assignment with KVM, pci_vfs_assigned() is not
updated. Please don't rely on this interface. Thanks,
Alex
next prev parent reply other threads:[~2014-08-20 12:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-20 11:09 How to get the number of VFs assigned to the guests in XEN Sreekanth Reddy
2014-08-20 12:46 ` Alex Williamson [this message]
2014-08-20 13:44 ` Sreekanth Reddy
2014-08-20 14:09 ` Alex Williamson
[not found] <CAK=zhgpH2tG-EG4QP1SE46e+uHXA+GJGOPA1vi8UqAfRZ-EFTA@mail.gmail.com>
2014-08-20 22:29 ` Konrad Rzeszutek Wilk
2014-08-21 8:20 ` Sreekanth Reddy
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