All of lore.kernel.org
 help / color / mirror / Atom feed
From: Alex Williamson <alex.williamson@redhat.com>
To: alex.williamson@redhat.com
Cc: cohuck@redhat.com, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, jgg@nvidia.com, peterx@redhat.com
Subject: [RFC PATCH 02/10] vfio: Update vfio_add_group_dev() API
Date: Mon, 22 Feb 2021 09:50:47 -0700	[thread overview]
Message-ID: <161401264735.16443.5908636631567017543.stgit@gimli.home> (raw)
In-Reply-To: <161401167013.16443.8389863523766611711.stgit@gimli.home>

Rather than an errno, return a pointer to the opaque vfio_device
to allow the bus driver to call into vfio-core without additional
lookups and references.  Note that bus drivers are still required
to use vfio_del_group_dev() to teardown the vfio_device.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/vfio/fsl-mc/vfio_fsl_mc.c            |    6 ++++--
 drivers/vfio/mdev/vfio_mdev.c                |    5 ++++-
 drivers/vfio/pci/vfio_pci.c                  |    7 +++++--
 drivers/vfio/platform/vfio_platform_common.c |    7 +++++--
 drivers/vfio/vfio.c                          |   23 ++++++++++-------------
 include/linux/vfio.h                         |    6 +++---
 6 files changed, 31 insertions(+), 23 deletions(-)

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
index f27e25112c40..a4c2d0b9cd51 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -592,6 +592,7 @@ 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;
+	struct vfio_device *device;
 	int ret;
 
 	group = vfio_iommu_group_get(dev);
@@ -608,8 +609,9 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
 
 	vdev->mc_dev = mc_dev;
 
-	ret = vfio_add_group_dev(dev, &vfio_fsl_mc_ops, vdev);
-	if (ret) {
+	device = vfio_add_group_dev(dev, &vfio_fsl_mc_ops, vdev);
+	if (IS_ERR(device)) {
+		ret = PTR_ERR(device);
 		dev_err(dev, "VFIO_FSL_MC: Failed to add to vfio group\n");
 		goto out_group_put;
 	}
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index b52eea128549..32901b265864 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -124,8 +124,11 @@ static const struct vfio_device_ops vfio_mdev_dev_ops = {
 static int vfio_mdev_probe(struct device *dev)
 {
 	struct mdev_device *mdev = to_mdev_device(dev);
+	struct vfio_device *device;
 
-	return vfio_add_group_dev(dev, &vfio_mdev_dev_ops, mdev);
+	device = vfio_add_group_dev(dev, &vfio_mdev_dev_ops, mdev);
+
+	return IS_ERR(device) ? PTR_ERR(device) : 0;
 }
 
 static void vfio_mdev_remove(struct device *dev)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 65e7e6b44578..f0a1d05f0137 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1926,6 +1926,7 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct vfio_pci_device *vdev;
 	struct iommu_group *group;
+	struct vfio_device *device;
 	int ret;
 
 	if (vfio_pci_is_denylisted(pdev))
@@ -1968,9 +1969,11 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	INIT_LIST_HEAD(&vdev->vma_list);
 	init_rwsem(&vdev->memory_lock);
 
-	ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
-	if (ret)
+	device = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
+	if (IS_ERR(device)) {
+		ret = PTR_ERR(device);
 		goto out_free;
+	}
 
 	ret = vfio_pci_reflck_attach(vdev);
 	if (ret)
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index fb4b385191f2..ff41fe0b758e 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -657,6 +657,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 			       struct device *dev)
 {
 	struct iommu_group *group;
+	struct vfio_device *device;
 	int ret;
 
 	if (!vdev)
@@ -685,9 +686,11 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 		goto put_reset;
 	}
 
-	ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
-	if (ret)
+	device = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
+	if (IS_ERR(device)) {
+		ret = PTR_ERR(device);
 		goto put_iommu;
+	}
 
 	mutex_init(&vdev->igate);
 
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 464caef97aff..067cd843961c 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -848,8 +848,9 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb,
 /**
  * VFIO driver API
  */
-int vfio_add_group_dev(struct device *dev,
-		       const struct vfio_device_ops *ops, void *device_data)
+struct vfio_device *vfio_add_group_dev(struct device *dev,
+				       const struct vfio_device_ops *ops,
+				       void *device_data)
 {
 	struct iommu_group *iommu_group;
 	struct vfio_group *group;
@@ -857,14 +858,14 @@ int vfio_add_group_dev(struct device *dev,
 
 	iommu_group = iommu_group_get(dev);
 	if (!iommu_group)
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 
 	group = vfio_group_get_from_iommu(iommu_group);
 	if (!group) {
 		group = vfio_create_group(iommu_group);
 		if (IS_ERR(group)) {
 			iommu_group_put(iommu_group);
-			return PTR_ERR(group);
+			return (struct vfio_device *)group;
 		}
 	} else {
 		/*
@@ -880,23 +881,19 @@ int vfio_add_group_dev(struct device *dev,
 			 iommu_group_id(iommu_group));
 		vfio_device_put(device);
 		vfio_group_put(group);
-		return -EBUSY;
+		return ERR_PTR(-EBUSY);
 	}
 
 	device = vfio_group_create_device(group, dev, ops, device_data);
-	if (IS_ERR(device)) {
-		vfio_group_put(group);
-		return PTR_ERR(device);
-	}
 
 	/*
-	 * Drop all but the vfio_device reference.  The vfio_device holds
-	 * a reference to the vfio_group, which holds a reference to the
-	 * iommu_group.
+	 * Drop all but the vfio_device reference.  The vfio_device, if
+	 * !IS_ERR() holds a reference to the vfio_group, which holds a
+	 * reference to the iommu_group.
 	 */
 	vfio_group_put(group);
 
-	return 0;
+	return device;
 }
 EXPORT_SYMBOL_GPL(vfio_add_group_dev);
 
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index b7e18bde5aa8..b784463000d4 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -48,9 +48,9 @@ struct vfio_device_ops {
 extern struct iommu_group *vfio_iommu_group_get(struct device *dev);
 extern void vfio_iommu_group_put(struct iommu_group *group, struct device *dev);
 
-extern int vfio_add_group_dev(struct device *dev,
-			      const struct vfio_device_ops *ops,
-			      void *device_data);
+extern struct vfio_device *vfio_add_group_dev(struct device *dev,
+					const struct vfio_device_ops *ops,
+					void *device_data);
 
 extern void *vfio_del_group_dev(struct device *dev);
 extern struct vfio_device *vfio_device_get_from_dev(struct device *dev);


  parent reply	other threads:[~2021-02-22 16:53 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-22 16:50 [RFC PATCH 00/10] vfio: Device memory DMA mapping improvements Alex Williamson
2021-02-22 16:50 ` [RFC PATCH 01/10] vfio: Create vfio_fs_type with inode per device Alex Williamson
2021-02-26  5:38   ` Christoph Hellwig
2021-02-26 13:15     ` Jason Gunthorpe
2021-02-22 16:50 ` Alex Williamson [this message]
2021-02-22 17:01   ` [RFC PATCH 02/10] vfio: Update vfio_add_group_dev() API Jason Gunthorpe
2021-02-22 16:50 ` [RFC PATCH 03/10] vfio: Export unmap_mapping_range() wrapper Alex Williamson
2021-02-22 16:51 ` [RFC PATCH 04/10] vfio/pci: Use vfio_device_unmap_mapping_range() Alex Williamson
2021-02-22 17:22   ` Jason Gunthorpe
2021-02-24 21:55     ` Alex Williamson
2021-02-25  0:57       ` Jason Gunthorpe
2021-02-22 16:51 ` [RFC PATCH 05/10] vfio: Create a vfio_device from vma lookup Alex Williamson
2021-02-22 17:29   ` Jason Gunthorpe
2021-02-24 21:55     ` Alex Williamson
2021-02-25  0:06       ` Jason Gunthorpe
2021-02-25 22:21         ` Alex Williamson
2021-02-25 23:49           ` Jason Gunthorpe
2021-03-04 21:37             ` Alex Williamson
2021-03-04 23:16               ` Jason Gunthorpe
2021-03-05  0:07                 ` Alex Williamson
2021-03-05  0:36                   ` Jason Gunthorpe
2021-02-22 16:51 ` [RFC PATCH 06/10] vfio: Add a device notifier interface Alex Williamson
2021-02-22 16:51 ` [RFC PATCH 07/10] vfio/pci: Notify on device release Alex Williamson
2021-02-22 16:52 ` [RFC PATCH 08/10] vfio/type1: Refactor pfn_list clearing Alex Williamson
2021-02-22 16:52 ` [RFC PATCH 09/10] vfio/type1: Pass iommu and dma objects through to vaddr_get_pfn Alex Williamson
2021-02-22 16:52 ` [RFC PATCH 10/10] vfio/type1: Register device notifier Alex Williamson
2021-02-22 17:55   ` Jason Gunthorpe
2021-02-24 21:55     ` Alex Williamson
2021-02-25  0:22       ` Jason Gunthorpe
2021-02-25 17:54         ` Peter Xu
2021-02-25 18:19           ` Jason Gunthorpe
2021-02-25 19:06             ` Peter Xu
2021-02-25 19:17               ` Jason Gunthorpe
2021-02-25 19:54                 ` Peter Xu
2021-02-26  5:47     ` Christoph Hellwig
2021-02-22 18:00 ` [RFC PATCH 00/10] vfio: Device memory DMA mapping improvements Jason Gunthorpe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=161401264735.16443.5908636631567017543.stgit@gimli.home \
    --to=alex.williamson@redhat.com \
    --cc=cohuck@redhat.com \
    --cc=jgg@nvidia.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=peterx@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.