diff mbox

[RFC,2/3] vfio: report group noiommu status

Message ID 1460973374-32719-3-git-send-email-mst@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Michael S. Tsirkin April 18, 2016, 9:58 a.m. UTC 
When using vfio, callers might want to know whether device is added to a
regular group or an non-iommu group.

Report this status from vfio_add_group_dev.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/vfio/pci/vfio_pci.c                  | 2 +-
 drivers/vfio/platform/vfio_platform_common.c | 2 +-
 drivers/vfio/vfio.c                          | 5 ++++-
 Documentation/vfio.txt                       | 4 +++-
 4 files changed, 9 insertions(+), 4 deletions(-)

Comments

Alex Williamson April 18, 2016, 6:56 p.m. UTC | #1 
On Mon, 18 Apr 2016 12:58:20 +0300
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> When using vfio, callers might want to know whether device is added to a
> regular group or an non-iommu group.
> 
> Report this status from vfio_add_group_dev.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---

What about making an interface to query this rather than playing games
with magic return values?

bool vfio_iommu_group_is_noiommu(struct iommu_group *group)
{
    return iommu_group_get_iommudata(group) == &noiommu;
}

>  drivers/vfio/pci/vfio_pci.c                  | 2 +-
>  drivers/vfio/platform/vfio_platform_common.c | 2 +-
>  drivers/vfio/vfio.c                          | 5 ++++-
>  Documentation/vfio.txt                       | 4 +++-
>  4 files changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> index 712a849..d622a41 100644
> --- a/drivers/vfio/pci/vfio_pci.c
> +++ b/drivers/vfio/pci/vfio_pci.c
> @@ -1119,7 +1119,7 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  	spin_lock_init(&vdev->irqlock);
>  
>  	ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
> -	if (ret) {
> +	if (ret < 0) {
>  		vfio_iommu_group_put(group, &pdev->dev);
>  		kfree(vdev);
>  		return ret;
> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> index e65b142..bf74e21 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -568,7 +568,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>  	}
>  
>  	ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
> -	if (ret) {
> +	if (ret < 0) {
>  		iommu_group_put(group);
>  		return ret;
>  	}
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 6fd6fa5..67db231 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -756,6 +756,7 @@ int vfio_add_group_dev(struct device *dev,
>  	struct iommu_group *iommu_group;
>  	struct vfio_group *group;
>  	struct vfio_device *device;
> +	int noiommu;
>  
>  	iommu_group = iommu_group_get(dev);
>  	if (!iommu_group)
> @@ -791,6 +792,8 @@ int vfio_add_group_dev(struct device *dev,
>  		return PTR_ERR(device);
>  	}
>  
> +	noiommu = group->noiommu;
> +
>  	/*
>  	 * Drop all but the vfio_device reference.  The vfio_device holds
>  	 * a reference to the vfio_group, which holds a reference to the
> @@ -798,7 +801,7 @@ int vfio_add_group_dev(struct device *dev,
>  	 */
>  	vfio_group_put(group);
>  
> -	return 0;
> +	return noiommu;
>  }
>  EXPORT_SYMBOL_GPL(vfio_add_group_dev);
>  
> diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt
> index 1dd3fdd..d76be0f 100644
> --- a/Documentation/vfio.txt
> +++ b/Documentation/vfio.txt
> @@ -259,7 +259,9 @@ extern void *vfio_del_group_dev(struct device *dev);
>  
>  vfio_add_group_dev() indicates to the core to begin tracking the
>  specified iommu_group and register the specified dev as owned by
> -a VFIO bus driver.  The driver provides an ops structure for callbacks
> +a VFIO bus driver.  A negative return value indicates failure.
> +A positive return value indicates that an unsafe noiommu mode
> +is in use.  The driver provides an ops structure for callbacks
>  similar to a file operations structure:
>  
>  struct vfio_device_ops {

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diff mbox

Patch

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 712a849..d622a41 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1119,7 +1119,7 @@  static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	spin_lock_init(&vdev->irqlock);
 
 	ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
-	if (ret) {
+	if (ret < 0) {
 		vfio_iommu_group_put(group, &pdev->dev);
 		kfree(vdev);
 		return ret;
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index e65b142..bf74e21 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -568,7 +568,7 @@  int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 	}
 
 	ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
-	if (ret) {
+	if (ret < 0) {
 		iommu_group_put(group);
 		return ret;
 	}
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 6fd6fa5..67db231 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -756,6 +756,7 @@  int vfio_add_group_dev(struct device *dev,
 	struct iommu_group *iommu_group;
 	struct vfio_group *group;
 	struct vfio_device *device;
+	int noiommu;
 
 	iommu_group = iommu_group_get(dev);
 	if (!iommu_group)
@@ -791,6 +792,8 @@  int vfio_add_group_dev(struct device *dev,
 		return PTR_ERR(device);
 	}
 
+	noiommu = group->noiommu;
+
 	/*
 	 * Drop all but the vfio_device reference.  The vfio_device holds
 	 * a reference to the vfio_group, which holds a reference to the
@@ -798,7 +801,7 @@  int vfio_add_group_dev(struct device *dev,
 	 */
 	vfio_group_put(group);
 
-	return 0;
+	return noiommu;
 }
 EXPORT_SYMBOL_GPL(vfio_add_group_dev);
 
diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt
index 1dd3fdd..d76be0f 100644
--- a/Documentation/vfio.txt
+++ b/Documentation/vfio.txt
@@ -259,7 +259,9 @@  extern void *vfio_del_group_dev(struct device *dev);
 
 vfio_add_group_dev() indicates to the core to begin tracking the
 specified iommu_group and register the specified dev as owned by
-a VFIO bus driver.  The driver provides an ops structure for callbacks
+a VFIO bus driver.  A negative return value indicates failure.
+A positive return value indicates that an unsafe noiommu mode
+is in use.  The driver provides an ops structure for callbacks
 similar to a file operations structure:
 
 struct vfio_device_ops {