Re: [PATCH v8 11/22] KVM: s390: pci: add basic kvm_zdev structure

[Matthew Rosato]

On 5/24/22 6:50 PM, Alex Williamson wrote:
> On Tue, 24 May 2022 14:58:56 -0400
> Matthew Rosato <mjrosato@xxxxxxxxxxxxx> wrote:
> > diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
> > new file mode 100644
> > index 000000000000..21c2be5c2713
> > --- /dev/null
> > +++ b/arch/s390/kvm/pci.c
> > @@ -0,0 +1,36 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * s390 kvm PCI passthrough support
> > + *
> > + * Copyright IBM Corp. 2022
> > + *
> > + *    Author(s): Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
> > + */
> > +
> > +#include <linux/kvm_host.h>
> > +#include <linux/pci.h>
> > +#include "pci.h"
> > +
> > +static int kvm_s390_pci_dev_open(struct zpci_dev *zdev)
> > +{
> > +	struct kvm_zdev *kzdev;
> > +
> > +	kzdev = kzalloc(sizeof(struct kvm_zdev), GFP_KERNEL);
> > +	if (!kzdev)
> > +		return -ENOMEM;
> > +
> > +	kzdev->zdev = zdev;
> > +	zdev->kzdev = kzdev;
> > +
> > +	return 0;
> > +}
> > +
> > +static void kvm_s390_pci_dev_release(struct zpci_dev *zdev)
> > +{
> > +	struct kvm_zdev *kzdev;
> > +
> > +	kzdev = zdev->kzdev;
> > +	WARN_ON(kzdev->zdev != zdev);
> > +	zdev->kzdev = 0;
>
> I imagine this should be s/0/NULL/, right?  I feel like there was a
> recent similar discussion, but I can't think of any unique search terms
> to sort it out of my inbox.  Thanks,

Yup, I recall a similar comment on a prior version but I don't recall if 
it was this particular patch or not -- anyway will change