diff mbox series

[01/14] vfio: Move vfio_iommu_group_get() to vfio_register_group_dev()

Message ID 20210824144649.1488190-2-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [01/14] vfio: Move vfio_iommu_group_get() to vfio_register_group_dev() | expand

Commit Message

Christoph Hellwig Aug. 24, 2021, 2:46 p.m. UTC 
From: Jason Gunthorpe <jgg@nvidia.com>

We don't need to hold a reference to the group in the driver as well as
obtain a reference to the same group as the first thing
vfio_register_group_dev() does.

Since the drivers never use the group move this all into the core code.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/vfio/fsl-mc/vfio_fsl_mc.c            | 17 ++-----------
 drivers/vfio/pci/vfio_pci.c                  | 15 ++----------
 drivers/vfio/platform/vfio_platform_common.c | 13 +---------
 drivers/vfio/vfio.c                          | 25 ++++++--------------
 include/linux/vfio.h                         |  3 ---
 5 files changed, 12 insertions(+), 61 deletions(-)

Comments

Alex Williamson Aug. 24, 2021, 8:25 p.m. UTC | #1 
On Tue, 24 Aug 2021 16:46:36 +0200
Christoph Hellwig <hch@lst.de> wrote:

> From: Jason Gunthorpe <jgg@nvidia.com>
> 
> We don't need to hold a reference to the group in the driver as well as
> obtain a reference to the same group as the first thing
> vfio_register_group_dev() does.
> 
> Since the drivers never use the group move this all into the core code.
> 
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/vfio/fsl-mc/vfio_fsl_mc.c            | 17 ++-----------
>  drivers/vfio/pci/vfio_pci.c                  | 15 ++----------
>  drivers/vfio/platform/vfio_platform_common.c | 13 +---------
>  drivers/vfio/vfio.c                          | 25 ++++++--------------
>  include/linux/vfio.h                         |  3 ---
>  5 files changed, 12 insertions(+), 61 deletions(-)
> 
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index a4f44ea52fa324..b01c1c6cf1f5e6 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -1875,7 +1875,6 @@ static void vfio_pci_vga_uninit(struct vfio_pci_device *vdev)
>  static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  {
>  	struct vfio_pci_device *vdev;
> -	struct iommu_group *group;
>  	int ret;
>  
>  	if (vfio_pci_is_denylisted(pdev))
> @@ -1897,15 +1896,9 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  		return -EBUSY;
>  	}
>  
> -	group = vfio_iommu_group_get(&pdev->dev);
> -	if (!group)
> -		return -EINVAL;
> -
>  	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
> -	if (!vdev) {
> -		ret = -ENOMEM;
> -		goto out_group_put;
> -	}
> +	if (!vdev)
> +		return -ENOMEM;
>  
>  	vfio_init_group_dev(&vdev->vdev, &pdev->dev, &vfio_pci_ops);
>  	vdev->pdev = pdev;
> @@ -1971,8 +1964,6 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  	vfio_uninit_group_dev(&vdev->vdev);
>  	kfree(vdev->pm_save);
>  	kfree(vdev);
> -out_group_put:
> -	vfio_iommu_group_put(group, &pdev->dev);
>  	return ret;
>  }
>  
> @@ -1988,8 +1979,6 @@ static void vfio_pci_remove(struct pci_dev *pdev)
>  	vfio_uninit_group_dev(&vdev->vdev);
>  	vfio_pci_vga_uninit(vdev);
>  
> -	vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
> -
>  	if (!disable_idle_d3)
>  		vfio_pci_set_power_state(vdev, PCI_D0);
>  


I think this turns into the patch below on top of Yishai's
vfio-pci-core series.  Please verify.  If you'd like something
different, please post an update.  Thanks,

Alex

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index c67751948504..4134dceab3f7 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1807,7 +1807,6 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_uninit_device);
 int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
 {
 	struct pci_dev *pdev = vdev->pdev;
-	struct iommu_group *group;
 	int ret;
 
 	if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
@@ -1826,10 +1825,6 @@ int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
 		return -EBUSY;
 	}
 
-	group = vfio_iommu_group_get(&pdev->dev);
-	if (!group)
-		return -EINVAL;
-
 	if (pci_is_root_bus(pdev->bus)) {
 		ret = vfio_assign_device_set(&vdev->vdev, vdev);
 	} else if (!pci_probe_reset_slot(pdev->slot)) {
@@ -1843,10 +1838,10 @@ int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
 	}
 
 	if (ret)
-		goto out_group_put;
+		return ret;
 	ret = vfio_pci_vf_init(vdev);
 	if (ret)
-		goto out_group_put;
+		return ret;
 	ret = vfio_pci_vga_init(vdev);
 	if (ret)
 		goto out_vf;
@@ -1877,8 +1872,6 @@ int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
 		vfio_pci_set_power_state(vdev, PCI_D0);
 out_vf:
 	vfio_pci_vf_uninit(vdev);
-out_group_put:
-	vfio_iommu_group_put(group, &pdev->dev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(vfio_pci_core_register_device);
@@ -1894,8 +1887,6 @@ void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev)
 	vfio_pci_vf_uninit(vdev);
 	vfio_pci_vga_uninit(vdev);
 
-	vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
-
 	if (!disable_idle_d3)
 		vfio_pci_set_power_state(vdev, PCI_D0);
 }
Jason Gunthorpe Aug. 24, 2021, 10:50 p.m. UTC | #2 
On Tue, Aug 24, 2021 at 02:25:08PM -0600, Alex Williamson wrote:
> > @@ -1988,8 +1979,6 @@ static void vfio_pci_remove(struct pci_dev *pdev)
> >  	vfio_uninit_group_dev(&vdev->vdev);
> >  	vfio_pci_vga_uninit(vdev);
> >  
> > -	vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
> > -
> >  	if (!disable_idle_d3)
> >  		vfio_pci_set_power_state(vdev, PCI_D0);
> >  
> 
> 
> I think this turns into the patch below on top of Yishai's
> vfio-pci-core series.  Please verify.  If you'd like something
> different, please post an update.  Thanks,

It appears correct to me, thanks

Jason
Christoph Hellwig Aug. 25, 2021, 12:43 p.m. UTC | #3 
On Tue, Aug 24, 2021 at 02:25:08PM -0600, Alex Williamson wrote:
> I think this turns into the patch below on top of Yishai's
> vfio-pci-core series.  Please verify.  If you'd like something
> different, please post an update.  Thanks,

The change looks fine to me.  Does that mean you want me to rebase
on top of the above series?
Alex Williamson Aug. 25, 2021, 3:48 p.m. UTC | #4 
On Wed, 25 Aug 2021 14:43:03 +0200
Christoph Hellwig <hch@lst.de> wrote:

> On Tue, Aug 24, 2021 at 02:25:08PM -0600, Alex Williamson wrote:
> > I think this turns into the patch below on top of Yishai's
> > vfio-pci-core series.  Please verify.  If you'd like something
> > different, please post an update.  Thanks,  
> 
> The change looks fine to me.  Does that mean you want me to rebase
> on top of the above series?

I wish the answer here was more obvious, but we're still waiting for
PCI and scripts/mod/ acks for that series.  I note however that while
the functionality of other driver's having a userspace driver discovery
mechanism hinges on patches 9 & 10 of Yishai's series, those patches
can also be cleanly moved to the end of the series, or a follow-on
series if necessary, and current vfio-pci binding continues to work.

Should we go ahead and get final reviews for {1-8,11-13} of Yishai's
series to get them in my next branch so we have a consistent base to
work from?  Thanks,

Alex
Jason Gunthorpe Aug. 25, 2021, 4:08 p.m. UTC | #5 
On Wed, Aug 25, 2021 at 09:48:19AM -0600, Alex Williamson wrote:
> On Wed, 25 Aug 2021 14:43:03 +0200
> Christoph Hellwig <hch@lst.de> wrote:
> 
> > On Tue, Aug 24, 2021 at 02:25:08PM -0600, Alex Williamson wrote:
> > > I think this turns into the patch below on top of Yishai's
> > > vfio-pci-core series.  Please verify.  If you'd like something
> > > different, please post an update.  Thanks,  
> > 
> > The change looks fine to me.  Does that mean you want me to rebase
> > on top of the above series?
> 
> I wish the answer here was more obvious, but we're still waiting for
> PCI and scripts/mod/ acks for that series.  I note however that while
> the functionality of other driver's having a userspace driver discovery
> mechanism hinges on patches 9 & 10 of Yishai's series, those patches
> can also be cleanly moved to the end of the series, or a follow-on
> series if necessary, and current vfio-pci binding continues to work.
> 
> Should we go ahead and get final reviews for {1-8,11-13} of Yishai's
> series to get them in my next branch so we have a consistent base to
> work from?  Thanks,

I see Bjorn has just now ack'd the PCI parts so I think it is also
fine to go ahead. A subsystem is ultimately responsible to define the
modalias format under its bus, the file2alias changes are supposed to
track it.

Also I'm looking at past changes to file2alias and I don't really see
many acks..

Thanks,
Jason
diff mbox series

Patch

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
index 0ead91bfa83867..9e838fed560339 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -505,22 +505,13 @@  static void vfio_fsl_uninit_device(struct vfio_fsl_mc_device *vdev)
 
 static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
 {
-	struct iommu_group *group;
 	struct vfio_fsl_mc_device *vdev;
 	struct device *dev = &mc_dev->dev;
 	int ret;
 
-	group = vfio_iommu_group_get(dev);
-	if (!group) {
-		dev_err(dev, "VFIO_FSL_MC: No IOMMU group\n");
-		return -EINVAL;
-	}
-
 	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
-	if (!vdev) {
-		ret = -ENOMEM;
-		goto out_group_put;
-	}
+	if (!vdev)
+		return -ENOMEM;
 
 	vfio_init_group_dev(&vdev->vdev, dev, &vfio_fsl_mc_ops);
 	vdev->mc_dev = mc_dev;
@@ -556,8 +547,6 @@  static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
 out_uninit:
 	vfio_uninit_group_dev(&vdev->vdev);
 	kfree(vdev);
-out_group_put:
-	vfio_iommu_group_put(group, dev);
 	return ret;
 }
 
@@ -574,8 +563,6 @@  static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)
 
 	vfio_uninit_group_dev(&vdev->vdev);
 	kfree(vdev);
-	vfio_iommu_group_put(mc_dev->dev.iommu_group, dev);
-
 	return 0;
 }
 
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index a4f44ea52fa324..b01c1c6cf1f5e6 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1875,7 +1875,6 @@  static void vfio_pci_vga_uninit(struct vfio_pci_device *vdev)
 static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct vfio_pci_device *vdev;
-	struct iommu_group *group;
 	int ret;
 
 	if (vfio_pci_is_denylisted(pdev))
@@ -1897,15 +1896,9 @@  static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		return -EBUSY;
 	}
 
-	group = vfio_iommu_group_get(&pdev->dev);
-	if (!group)
-		return -EINVAL;
-
 	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
-	if (!vdev) {
-		ret = -ENOMEM;
-		goto out_group_put;
-	}
+	if (!vdev)
+		return -ENOMEM;
 
 	vfio_init_group_dev(&vdev->vdev, &pdev->dev, &vfio_pci_ops);
 	vdev->pdev = pdev;
@@ -1971,8 +1964,6 @@  static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	vfio_uninit_group_dev(&vdev->vdev);
 	kfree(vdev->pm_save);
 	kfree(vdev);
-out_group_put:
-	vfio_iommu_group_put(group, &pdev->dev);
 	return ret;
 }
 
@@ -1988,8 +1979,6 @@  static void vfio_pci_remove(struct pci_dev *pdev)
 	vfio_uninit_group_dev(&vdev->vdev);
 	vfio_pci_vga_uninit(vdev);
 
-	vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
-
 	if (!disable_idle_d3)
 		vfio_pci_set_power_state(vdev, PCI_D0);
 
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 6af7ce7d619c25..256f55b84e70a0 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -642,7 +642,6 @@  static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 			       struct device *dev)
 {
-	struct iommu_group *group;
 	int ret;
 
 	vfio_init_group_dev(&vdev->vdev, dev, &vfio_platform_ops);
@@ -663,24 +662,15 @@  int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 		goto out_uninit;
 	}
 
-	group = vfio_iommu_group_get(dev);
-	if (!group) {
-		dev_err(dev, "No IOMMU group for device %s\n", vdev->name);
-		ret = -EINVAL;
-		goto put_reset;
-	}
-
 	ret = vfio_register_group_dev(&vdev->vdev);
 	if (ret)
-		goto put_iommu;
+		goto put_reset;
 
 	mutex_init(&vdev->igate);
 
 	pm_runtime_enable(dev);
 	return 0;
 
-put_iommu:
-	vfio_iommu_group_put(group, dev);
 put_reset:
 	vfio_platform_put_reset(vdev);
 out_uninit:
@@ -696,7 +686,6 @@  void vfio_platform_remove_common(struct vfio_platform_device *vdev)
 	pm_runtime_disable(vdev->device);
 	vfio_platform_put_reset(vdev);
 	vfio_uninit_group_dev(&vdev->vdev);
-	vfio_iommu_group_put(vdev->vdev.dev->iommu_group, vdev->vdev.dev);
 }
 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
 
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 3c034fe14ccb03..5bd520f0dc6107 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -169,15 +169,7 @@  static void vfio_release_device_set(struct vfio_device *device)
 	xa_unlock(&vfio_device_set_xa);
 }
 
-/*
- * vfio_iommu_group_{get,put} are only intended for VFIO bus driver probe
- * and remove functions, any use cases other than acquiring the first
- * reference for the purpose of calling vfio_register_group_dev() or removing
- * that symmetric reference after vfio_unregister_group_dev() should use the raw
- * iommu_group_{get,put} functions.  In particular, vfio_iommu_group_put()
- * removes the device from the dummy group and cannot be nested.
- */
-struct iommu_group *vfio_iommu_group_get(struct device *dev)
+static struct iommu_group *vfio_iommu_group_get(struct device *dev)
 {
 	struct iommu_group *group;
 	int __maybe_unused ret;
@@ -220,9 +212,8 @@  struct iommu_group *vfio_iommu_group_get(struct device *dev)
 
 	return group;
 }
-EXPORT_SYMBOL_GPL(vfio_iommu_group_get);
 
-void vfio_iommu_group_put(struct iommu_group *group, struct device *dev)
+static void vfio_iommu_group_put(struct iommu_group *group, struct device *dev)
 {
 #ifdef CONFIG_VFIO_NOIOMMU
 	if (iommu_group_get_iommudata(group) == &noiommu)
@@ -231,7 +222,6 @@  void vfio_iommu_group_put(struct iommu_group *group, struct device *dev)
 
 	iommu_group_put(group);
 }
-EXPORT_SYMBOL_GPL(vfio_iommu_group_put);
 
 #ifdef CONFIG_VFIO_NOIOMMU
 static void *vfio_noiommu_open(unsigned long arg)
@@ -841,7 +831,7 @@  int vfio_register_group_dev(struct vfio_device *device)
 	if (!device->dev_set)
 		vfio_assign_device_set(device, device);
 
-	iommu_group = iommu_group_get(device->dev);
+	iommu_group = vfio_iommu_group_get(device->dev);
 	if (!iommu_group)
 		return -EINVAL;
 
@@ -849,7 +839,7 @@  int vfio_register_group_dev(struct vfio_device *device)
 	if (!group) {
 		group = vfio_create_group(iommu_group);
 		if (IS_ERR(group)) {
-			iommu_group_put(iommu_group);
+			vfio_iommu_group_put(iommu_group, device->dev);
 			return PTR_ERR(group);
 		}
 	} else {
@@ -857,7 +847,7 @@  int vfio_register_group_dev(struct vfio_device *device)
 		 * A found vfio_group already holds a reference to the
 		 * iommu_group.  A created vfio_group keeps the reference.
 		 */
-		iommu_group_put(iommu_group);
+		vfio_iommu_group_put(iommu_group, device->dev);
 	}
 
 	existing_device = vfio_group_get_device(group, device->dev);
@@ -865,7 +855,7 @@  int vfio_register_group_dev(struct vfio_device *device)
 		dev_WARN(device->dev, "Device already exists on group %d\n",
 			 iommu_group_id(iommu_group));
 		vfio_device_put(existing_device);
-		vfio_group_put(group);
+		vfio_iommu_group_put(iommu_group, device->dev);
 		return -EBUSY;
 	}
 
@@ -1010,8 +1000,7 @@  void vfio_unregister_group_dev(struct vfio_device *device)
 	if (list_empty(&group->device_list))
 		wait_event(group->container_q, !group->container);
 
-	/* Matches the get in vfio_register_group_dev() */
-	vfio_group_put(group);
+	vfio_iommu_group_put(group->iommu_group, device->dev);
 }
 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
 
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index b53a9557884ada..f7083c2fd0d099 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -71,9 +71,6 @@  struct vfio_device_ops {
 	int	(*match)(struct vfio_device *vdev, char *buf);
 };
 
-extern struct iommu_group *vfio_iommu_group_get(struct device *dev);
-extern void vfio_iommu_group_put(struct iommu_group *group, struct device *dev);
-
 void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
 			 const struct vfio_device_ops *ops);
 void vfio_uninit_group_dev(struct vfio_device *device);