From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bandan Das Subject: Re: [PATCH] vfio: Set PCI_DEV_FLAGS_ASSIGNED when assigning device to guest Date: Thu, 30 Jan 2014 23:36:31 +0530 Message-ID: References: <1391103225.6959.71.camel@bling.home> <1391103376.6959.72.camel@bling.home> Mime-Version: 1.0 Content-Type: text/plain Cc: kvm@vger.kernel.org, linux-pci To: Alex Williamson Return-path: In-Reply-To: <1391103376.6959.72.camel@bling.home> (Alex Williamson's message of "Thu, 30 Jan 2014 10:36:16 -0700") Sender: linux-pci-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Alex Williamson writes: > [cc +linux-pci] > > On Thu, 2014-01-30 at 10:33 -0700, Alex Williamson wrote: >> On Thu, 2014-01-30 at 22:54 +0530, Bandan Das wrote: >> > Some drivers such as ixgbe rely on pci_vfs_assigned() to prevent >> > disabling sr-iov when vfs are still assigned during hotplug >> > event or module removal. Set and unset PCI_DEV_FLAGS_ASSIGNED >> > appropriately >> >> This flag has always felt like a band-aide for KVM device assignment >> because a device could be used without an actual driver attached to the >> device. vfio-pci is an actual driver, so why should it matter whether >> the device is assigned or in use by ixgbevf or in use by pci-vfio? It >> seems like sr-iov shouldn't be disabled so long as either a driver or >> this (needs to be deprecated) flag are set. Thanks, With cases such as vfio-pci, not having this flag set will disable sriov while a guest is using it resulting in a hung guest. I am unfamiliar if similar scenarios are applicable to other test cases. If the flag needs to be set, what's a better place then ? Or how does the PF driver decide not to disable sr-iov, should it be based on - as long as the device is bound to a driver ? Bandan >> Alex >> >> > --- >> > drivers/vfio/pci/vfio_pci.c | 2 ++ >> > 1 file changed, 2 insertions(+) >> > >> > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c >> > index 7ba0424..7cc7ed6 100644 >> > --- a/drivers/vfio/pci/vfio_pci.c >> > +++ b/drivers/vfio/pci/vfio_pci.c >> > @@ -90,6 +90,7 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev) >> > vdev->has_vga = true; >> > #endif >> > >> > + pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED; >> > return 0; >> > } >> > >> > @@ -149,6 +150,7 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev) >> > __func__, dev_name(&pdev->dev), ret); >> > } >> > >> > + pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED; >> > pci_restore_state(pdev); >> > } >> > >> >> > > > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html