| Message ID | 20170112071947.98071-7-bjsdjshi@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 12 Jan 2017 08:19:38 +0100 Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> wrote: > To make vfio support subchannel devices, we need to leverage the > mediated device framework to create a mediated device for the > subchannel device. > > This registers the subchannel device to the mediated device > framework during probe to enable mediated device creation. > > Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> > Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com> > --- > arch/s390/Kconfig | 2 +- > drivers/s390/cio/Makefile | 2 +- > drivers/s390/cio/vfio_ccw_drv.c | 10 ++- > drivers/s390/cio/vfio_ccw_ops.c | 149 ++++++++++++++++++++++++++++++++++++ > drivers/s390/cio/vfio_ccw_private.h | 9 +++ > 5 files changed, 169 insertions(+), 3 deletions(-) > create mode 100644 drivers/s390/cio/vfio_ccw_ops.c > > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index b920df8..32008b8 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -673,7 +673,7 @@ config EADM_SCH > config VFIO_CCW > def_tristate n > prompt "Support for VFIO-CCW subchannels" > - depends on S390_CCW_IOMMU && VFIO > + depends on S390_CCW_IOMMU && VFIO_MDEV > help > This driver allows usage of VFIO-CCW subchannels. > > diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile > index 1bec279..b0586b2 100644 > --- a/drivers/s390/cio/Makefile > +++ b/drivers/s390/cio/Makefile > @@ -18,5 +18,5 @@ obj-$(CONFIG_CCWGROUP) += ccwgroup.o > qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o > obj-$(CONFIG_QDIO) += qdio.o > > -vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o > +vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o > obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o > diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c > index 5759d2a..ef34b15 100644 > --- a/drivers/s390/cio/vfio_ccw_drv.c > +++ b/drivers/s390/cio/vfio_ccw_drv.c > @@ -23,7 +23,7 @@ > /* > * Helpers > */ > -static int vfio_ccw_sch_quiesce(struct subchannel *sch) > +int vfio_ccw_sch_quiesce(struct subchannel *sch) > { > struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); > DECLARE_COMPLETION_ONSTACK(completion); > @@ -156,8 +156,14 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) > if (ret) > goto out_disable; > > + ret = vfio_ccw_mdev_reg(sch); > + if (ret) > + goto out_rm_group; > + > return 0; > > +out_rm_group: > + sysfs_remove_group(&sch->dev.kobj, &vfio_subchannel_attr_group); > out_disable: > cio_disable_subchannel(sch); > out_free: > @@ -172,6 +178,8 @@ static int vfio_ccw_sch_remove(struct subchannel *sch) > > vfio_ccw_sch_quiesce(sch); > > + vfio_ccw_mdev_unreg(sch); > + > sysfs_remove_group(&sch->dev.kobj, &vfio_subchannel_attr_group); > > dev_set_drvdata(&sch->dev, NULL); > diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c > new file mode 100644 > index 0000000..6031a10 > --- /dev/null > +++ b/drivers/s390/cio/vfio_ccw_ops.c > @@ -0,0 +1,149 @@ > +/* > + * Physical device callbacks for vfio_ccw > + * > + * Copyright IBM Corp. 2017 > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License (version 2 only) > + * as published by the Free Software Foundation. > + * > + * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> > + * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> > + */ > + > +#include <linux/vfio.h> > +#include <linux/mdev.h> > + > +#include "vfio_ccw_private.h" > + > +#define MAX_INSTANCES 1 > +static int available_instances = MAX_INSTANCES; > + > +static int vfio_ccw_mdev_notifier(struct notifier_block *nb, > + unsigned long action, > + void *data) > +{ > + struct vfio_ccw_private *private = > + container_of(nb, struct vfio_ccw_private, nb); > + > + if (!private) > + return NOTIFY_STOP; > + > + /* > + * TODO: > + * Vendor drivers MUST unpin pages in response to an > + * invalidation. > + */ > + if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) > + return NOTIFY_BAD; > + > + return NOTIFY_DONE; > +} > + > +static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf) > +{ > + return sprintf(buf, "I/O subchannel (Non-QDIO)\n"); > +} > +MDEV_TYPE_ATTR_RO(name); > + > +static ssize_t device_api_show(struct kobject *kobj, struct device *dev, > + char *buf) > +{ > + return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING); > +} > +MDEV_TYPE_ATTR_RO(device_api); > + > +static ssize_t available_instances_show(struct kobject *kobj, > + struct device *dev, char *buf) > +{ > + return sprintf(buf, "%d\n", available_instances); > +} > +MDEV_TYPE_ATTR_RO(available_instances); > + > +static struct attribute *mdev_types_attrs[] = { > + &mdev_type_attr_name.attr, > + &mdev_type_attr_device_api.attr, > + &mdev_type_attr_available_instances.attr, > + NULL, > +}; > + > +static struct attribute_group mdev_type_group = { > + .name = "io", > + .attrs = mdev_types_attrs, > +}; > + > +struct attribute_group *mdev_type_groups[] = { > + &mdev_type_group, > + NULL, > +}; > + > +static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev) > +{ > + struct vfio_ccw_private *private = dev_get_drvdata(mdev->parent->dev); > + > + /* Only support one mediated device for each physical subchannel. */ > + if (private->mdev) > + return -EPERM; > + > + private->mdev = mdev; > + available_instances--; This looks racy and doesn't enforce the available instances. Should this maybe be an atomic_t and use atomic_dec_if_positive() to return an error if no instances are available? > + > + return 0; > +} > + > +static int vfio_ccw_mdev_remove(struct mdev_device *mdev) > +{ > + struct vfio_ccw_private *private = dev_get_drvdata(mdev->parent->dev); > + struct subchannel *sch; > + int ret; > + > + sch = private->sch; > + ret = vfio_ccw_sch_quiesce(sch); > + if (ret) > + return ret; > + ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); > + if (ret) > + return ret; > + > + private->mdev = NULL; > + available_instances++; > + > + return 0; > +} > + > +static int vfio_ccw_mdev_open(struct mdev_device *mdev) > +{ > + struct vfio_ccw_private *private = dev_get_drvdata(mdev->parent->dev); > + unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; > + > + private->nb.notifier_call = vfio_ccw_mdev_notifier; > + > + return vfio_register_notifier(&mdev->dev, VFIO_IOMMU_NOTIFY, > + &events, &private->nb); > +} > + > +void vfio_ccw_mdev_release(struct mdev_device *mdev) > +{ > + struct vfio_ccw_private *private = dev_get_drvdata(mdev->parent->dev); > + > + vfio_unregister_notifier(&mdev->dev, VFIO_IOMMU_NOTIFY, &private->nb); > +} > + > +static const struct parent_ops vfio_ccw_mdev_ops = { > + .owner = THIS_MODULE, > + .supported_type_groups = mdev_type_groups, > + .create = vfio_ccw_mdev_create, > + .remove = vfio_ccw_mdev_remove, > + .open = vfio_ccw_mdev_open, > + .release = vfio_ccw_mdev_release, > +}; > + > +int vfio_ccw_mdev_reg(struct subchannel *sch) > +{ > + return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops); > +} > + > +void vfio_ccw_mdev_unreg(struct subchannel *sch) > +{ > + mdev_unregister_device(&sch->dev); > +} > diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h > index 1617c96..4cd6657 100644 > --- a/drivers/s390/cio/vfio_ccw_private.h > +++ b/drivers/s390/cio/vfio_ccw_private.h > @@ -20,10 +20,19 @@ > * struct vfio_ccw_private > * @sch: pointor to the subchannel > * @completion: synchronization helper of the I/O completion > + * @mdev: pointor to the mediated device > + * @nb: notifier for vfio events > */ > struct vfio_ccw_private { > struct subchannel *sch; > struct completion *completion; > + struct mdev_device *mdev; > + struct notifier_block nb; > } __aligned(8); > > +extern int vfio_ccw_mdev_reg(struct subchannel *sch); > +extern void vfio_ccw_mdev_unreg(struct subchannel *sch); > + > +extern int vfio_ccw_sch_quiesce(struct subchannel *sch); > + > #endif -- 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
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index b920df8..32008b8 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -673,7 +673,7 @@ config EADM_SCH config VFIO_CCW def_tristate n prompt "Support for VFIO-CCW subchannels" - depends on S390_CCW_IOMMU && VFIO + depends on S390_CCW_IOMMU && VFIO_MDEV help This driver allows usage of VFIO-CCW subchannels. diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile index 1bec279..b0586b2 100644 --- a/drivers/s390/cio/Makefile +++ b/drivers/s390/cio/Makefile @@ -18,5 +18,5 @@ obj-$(CONFIG_CCWGROUP) += ccwgroup.o qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o obj-$(CONFIG_QDIO) += qdio.o -vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o +vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 5759d2a..ef34b15 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -23,7 +23,7 @@ /* * Helpers */ -static int vfio_ccw_sch_quiesce(struct subchannel *sch) +int vfio_ccw_sch_quiesce(struct subchannel *sch) { struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); DECLARE_COMPLETION_ONSTACK(completion); @@ -156,8 +156,14 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) if (ret) goto out_disable; + ret = vfio_ccw_mdev_reg(sch); + if (ret) + goto out_rm_group; + return 0; +out_rm_group: + sysfs_remove_group(&sch->dev.kobj, &vfio_subchannel_attr_group); out_disable: cio_disable_subchannel(sch); out_free: @@ -172,6 +178,8 @@ static int vfio_ccw_sch_remove(struct subchannel *sch) vfio_ccw_sch_quiesce(sch); + vfio_ccw_mdev_unreg(sch); + sysfs_remove_group(&sch->dev.kobj, &vfio_subchannel_attr_group); dev_set_drvdata(&sch->dev, NULL); diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c new file mode 100644 index 0000000..6031a10 --- /dev/null +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -0,0 +1,149 @@ +/* + * Physical device callbacks for vfio_ccw + * + * Copyright IBM Corp. 2017 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License (version 2 only) + * as published by the Free Software Foundation. + * + * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> + * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> + */ + +#include <linux/vfio.h> +#include <linux/mdev.h> + +#include "vfio_ccw_private.h" + +#define MAX_INSTANCES 1 +static int available_instances = MAX_INSTANCES; + +static int vfio_ccw_mdev_notifier(struct notifier_block *nb, + unsigned long action, + void *data) +{ + struct vfio_ccw_private *private = + container_of(nb, struct vfio_ccw_private, nb); + + if (!private) + return NOTIFY_STOP; + + /* + * TODO: + * Vendor drivers MUST unpin pages in response to an + * invalidation. + */ + if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) + return NOTIFY_BAD; + + return NOTIFY_DONE; +} + +static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf) +{ + return sprintf(buf, "I/O subchannel (Non-QDIO)\n"); +} +MDEV_TYPE_ATTR_RO(name); + +static ssize_t device_api_show(struct kobject *kobj, struct device *dev, + char *buf) +{ + return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING); +} +MDEV_TYPE_ATTR_RO(device_api); + +static ssize_t available_instances_show(struct kobject *kobj, + struct device *dev, char *buf) +{ + return sprintf(buf, "%d\n", available_instances); +} +MDEV_TYPE_ATTR_RO(available_instances); + +static struct attribute *mdev_types_attrs[] = { + &mdev_type_attr_name.attr, + &mdev_type_attr_device_api.attr, + &mdev_type_attr_available_instances.attr, + NULL, +}; + +static struct attribute_group mdev_type_group = { + .name = "io", + .attrs = mdev_types_attrs, +}; + +struct attribute_group *mdev_type_groups[] = { + &mdev_type_group, + NULL, +}; + +static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev) +{ + struct vfio_ccw_private *private = dev_get_drvdata(mdev->parent->dev); + + /* Only support one mediated device for each physical subchannel. */ + if (private->mdev) + return -EPERM; + + private->mdev = mdev; + available_instances--; + + return 0; +} + +static int vfio_ccw_mdev_remove(struct mdev_device *mdev) +{ + struct vfio_ccw_private *private = dev_get_drvdata(mdev->parent->dev); + struct subchannel *sch; + int ret; + + sch = private->sch; + ret = vfio_ccw_sch_quiesce(sch); + if (ret) + return ret; + ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); + if (ret) + return ret; + + private->mdev = NULL; + available_instances++; + + return 0; +} + +static int vfio_ccw_mdev_open(struct mdev_device *mdev) +{ + struct vfio_ccw_private *private = dev_get_drvdata(mdev->parent->dev); + unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP; + + private->nb.notifier_call = vfio_ccw_mdev_notifier; + + return vfio_register_notifier(&mdev->dev, VFIO_IOMMU_NOTIFY, + &events, &private->nb); +} + +void vfio_ccw_mdev_release(struct mdev_device *mdev) +{ + struct vfio_ccw_private *private = dev_get_drvdata(mdev->parent->dev); + + vfio_unregister_notifier(&mdev->dev, VFIO_IOMMU_NOTIFY, &private->nb); +} + +static const struct parent_ops vfio_ccw_mdev_ops = { + .owner = THIS_MODULE, + .supported_type_groups = mdev_type_groups, + .create = vfio_ccw_mdev_create, + .remove = vfio_ccw_mdev_remove, + .open = vfio_ccw_mdev_open, + .release = vfio_ccw_mdev_release, +}; + +int vfio_ccw_mdev_reg(struct subchannel *sch) +{ + return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops); +} + +void vfio_ccw_mdev_unreg(struct subchannel *sch) +{ + mdev_unregister_device(&sch->dev); +} diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h index 1617c96..4cd6657 100644 --- a/drivers/s390/cio/vfio_ccw_private.h +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -20,10 +20,19 @@ * struct vfio_ccw_private * @sch: pointor to the subchannel * @completion: synchronization helper of the I/O completion + * @mdev: pointor to the mediated device + * @nb: notifier for vfio events */ struct vfio_ccw_private { struct subchannel *sch; struct completion *completion; + struct mdev_device *mdev; + struct notifier_block nb; } __aligned(8); +extern int vfio_ccw_mdev_reg(struct subchannel *sch); +extern void vfio_ccw_mdev_unreg(struct subchannel *sch); + +extern int vfio_ccw_sch_quiesce(struct subchannel *sch); + #endif