Re: [PATCH 1/1] virt/kvm/iommu.c: Add leading zeros to device's BDFnotation in debug messages

From: Alex Williamson
Date: Wed Oct 02 2013 - 11:41:25 EST


On Wed, 2013-10-02 at 13:35 +0300, Gleb Natapov wrote:
> On Wed, Oct 02, 2013 at 12:23:26PM +0200, Andre Richter wrote:
> > When KVM (de)assigns PCI(e) devices to VMs, a debug message is printed
> > including the BDF notation of the respective device. Currently, the BDF
> > notation does not have the commonly used leading zeros. This produces
> > messages like "assign device 0:1:8.0", which look strange at first sight.
> >
> > The patch fixes this by exchanging the printk(KERN_DEBUG ...) with dev_info()
> > and also inserts "kvm" into the debug message, so that it is obvious where
> > the message comes from. Also reduces LoC.
> Legacy assigned device is deprecated, but this looks nice enough to
> apply. Alex can you glance at it?

Seems ok to me, my only question would be why are we promoting this from
KERN_DEBUG to KERN_INFO. We could use dev_dbg() to maintain the same
kernel log level. A nice feature of either is that it prints out the
attached driver so we can see in dmesg whether the device is attached to
a host driver, nothing, or pci-stub. Thanks,

Alex

> >
> > Signed-off-by: Andre Richter <andre.o.richter@xxxxxxxxx>
> > ---
> > virt/kvm/iommu.c | 12 ++----------
> > 1 file changed, 2 insertions(+), 10 deletions(-)
> >
> > diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
> > index 72a130b..a3b1410 100644
> > --- a/virt/kvm/iommu.c
> > +++ b/virt/kvm/iommu.c
> > @@ -190,11 +190,7 @@ int kvm_assign_device(struct kvm *kvm,
> >
> > pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
> >
> > - printk(KERN_DEBUG "assign device %x:%x:%x.%x\n",
> > - assigned_dev->host_segnr,
> > - assigned_dev->host_busnr,
> > - PCI_SLOT(assigned_dev->host_devfn),
> > - PCI_FUNC(assigned_dev->host_devfn));
> > + dev_info(&pdev->dev, "kvm assign device\n");
> >
> > return 0;
> > out_unmap:
> > @@ -220,11 +216,7 @@ int kvm_deassign_device(struct kvm *kvm,
> >
> > pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
> >
> > - printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n",
> > - assigned_dev->host_segnr,
> > - assigned_dev->host_busnr,
> > - PCI_SLOT(assigned_dev->host_devfn),
> > - PCI_FUNC(assigned_dev->host_devfn));
> > + dev_info(&pdev->dev, "kvm deassign device\n");
> >
> > return 0;
> > }
> > --
> > 1.8.1.2
>
> --
> Gleb.



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