Hi Alex, > From: Alex Williamson [mailto:alex.williamson@xxxxxxxxxx] > Sent: Thursday, September 26, 2019 10:37 AM > To: Liu, Yi L <yi.l.liu@xxxxxxxxx> > > Subject: Re: [PATCH v2 10/13] samples: refine vfio-mdev-pci driver > > On Thu, 5 Sep 2019 15:59:27 +0800 > Liu Yi L <yi.l.liu@xxxxxxxxx> wrote: > > > From: Alex Williamson <alex.williamson@xxxxxxxxxx> > > > > This patch refines the implementation of original vfio-mdev-pci driver. > > > > And the vfio-mdev-pci-type_name will be named per the following rule: > > > > vmdev->attr.name = kasprintf(GFP_KERNEL, > > "%04x:%04x:%04x:%04x:%06x:%02x", > > pdev->vendor, pdev->device, > > pdev->subsystem_vendor, > > pdev->subsystem_device, pdev->class, > > pdev->revision); > > > > Before usage, check the > > /sys/bus/pci/devices/$bdf/mdev_supported_types/ > > to ensure the final mdev_supported_types. > > > > Cc: Kevin Tian <kevin.tian@xxxxxxxxx> > > Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> > > Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx> > > Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx> > > --- > > drivers/vfio/pci/vfio_mdev_pci.c | 123 > > +++++++++++++++++++++++---------------- > > 1 file changed, 72 insertions(+), 51 deletions(-) > > > > diff --git a/drivers/vfio/pci/vfio_mdev_pci.c > > b/drivers/vfio/pci/vfio_mdev_pci.c > > index 07c8067..09143d3 100644 > > --- a/drivers/vfio/pci/vfio_mdev_pci.c > > +++ b/drivers/vfio/pci/vfio_mdev_pci.c > > @@ -65,18 +65,22 @@ MODULE_PARM_DESC(disable_idle_d3, > > > > static struct pci_driver vfio_mdev_pci_driver; > > > > -static ssize_t > > -name_show(struct kobject *kobj, struct device *dev, char *buf) -{ > > - return sprintf(buf, "%s-type1\n", dev_name(dev)); > > -} > > - > > -MDEV_TYPE_ATTR_RO(name); > > +struct vfio_mdev_pci_device { > > + struct vfio_pci_device vdev; > > + struct mdev_parent_ops ops; > > + struct attribute_group *groups[2]; > > + struct attribute_group attr; > > + atomic_t avail; > > +}; > > > > static ssize_t > > available_instances_show(struct kobject *kobj, struct device *dev, > > char *buf) { > > - return sprintf(buf, "%d\n", 1); > > + struct vfio_mdev_pci_device *vmdev; > > + > > + vmdev = pci_get_drvdata(to_pci_dev(dev)); > > + > > + return sprintf(buf, "%d\n", atomic_read(&vmdev->avail)); > > } > > > > MDEV_TYPE_ATTR_RO(available_instances); > > @@ -90,62 +94,57 @@ static ssize_t device_api_show(struct kobject > > *kobj, struct device *dev, MDEV_TYPE_ATTR_RO(device_api); > > > > static struct attribute *vfio_mdev_pci_types_attrs[] = { > > - &mdev_type_attr_name.attr, > > &mdev_type_attr_device_api.attr, > > &mdev_type_attr_available_instances.attr, > > NULL, > > }; > > > > -static struct attribute_group vfio_mdev_pci_type_group1 = { > > - .name = "type1", > > - .attrs = vfio_mdev_pci_types_attrs, > > -}; > > - > > -struct attribute_group *vfio_mdev_pci_type_groups[] = { > > - &vfio_mdev_pci_type_group1, > > - NULL, > > -}; > > - > > struct vfio_mdev_pci { > > struct vfio_pci_device *vdev; > > struct mdev_device *mdev; > > - unsigned long handle; > > }; > > > > static int vfio_mdev_pci_create(struct kobject *kobj, struct > > mdev_device *mdev) { > > struct device *pdev; > > - struct vfio_pci_device *vdev; > > + struct vfio_mdev_pci_device *vmdev; > > struct vfio_mdev_pci *pmdev; > > int ret; > > > > pdev = mdev_parent_dev(mdev); > > - vdev = dev_get_drvdata(pdev); > > + vmdev = dev_get_drvdata(pdev); > > + > > + if (atomic_dec_if_positive(&vmdev->avail) < 0) > > + return -ENOSPC; > > + > > pmdev = kzalloc(sizeof(struct vfio_mdev_pci), GFP_KERNEL); > > - if (pmdev == NULL) { > > - ret = -EBUSY; > > - goto out; > > - } > > + if (!pmdev) > > + return -ENOMEM; > > Needs an atomic_inc(&vmdev->avail) in this error path. Thanks, Oops, yes it is. > > Alex Thanks, Yi Liu
