diff mbox series

[v4,7/9] vfio-iommufd: Add helper to retrieve iommufd_ctx and devid for vfio_device

Message ID 20230426145419.450922-8-yi.l.liu@intel.com (mailing list archive)
State New, archived
Headers show
Series Enhance vfio PCI hot reset for vfio cdev device | expand

Commit Message

Yi Liu April 26, 2023, 2:54 p.m. UTC 
This is needed by the vfio-pci driver to report affected devices in the
hot reset for a given device.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 drivers/iommu/iommufd/device.c | 24 ++++++++++++++++++++++++
 drivers/vfio/iommufd.c         | 24 ++++++++++++++++++++++++
 include/linux/iommufd.h        |  6 ++++++
 include/linux/vfio.h           | 14 ++++++++++++++
 4 files changed, 68 insertions(+)

Comments

Tian, Kevin April 27, 2023, 6:45 a.m. UTC | #1 
> From: Yi Liu
> Sent: Wednesday, April 26, 2023 10:54 PM
> +
> +/*
> + * Return devid for devices that have been bound with iommufd,
> + * returns 0 if not bound yet.
> + */
> +u32 vfio_iommufd_physical_devid(struct vfio_device *vdev)
> +{
> +	if (WARN_ON(!vdev->iommufd_device && !vdev->iommufd_access))
> +		return 0;

is WARN_ON too restrictive?
Yi Liu April 27, 2023, 7:15 a.m. UTC | #2 
> From: Tian, Kevin <kevin.tian@intel.com>
> Sent: Thursday, April 27, 2023 2:46 PM
> 
> > From: Yi Liu
> > Sent: Wednesday, April 26, 2023 10:54 PM
> > +
> > +/*
> > + * Return devid for devices that have been bound with iommufd,
> > + * returns 0 if not bound yet.
> > + */
> > +u32 vfio_iommufd_physical_devid(struct vfio_device *vdev)
> > +{
> > +	if (WARN_ON(!vdev->iommufd_device && !vdev->iommufd_access))
> > +		return 0;
> 
> is WARN_ON too restrictive?

This originated from a comment from Eric[1]. At that time, this helper is
void type, hence there is no message when there is no devid. Now, this returns
0 if the device is not bound. Maybe checking it in the caller and warn on
there?

[1] https://lore.kernel.org/kvm/702c2883-1d51-b609-1e99-337295e6e307@redhat.com/

Regards,
Yi Liu
diff mbox series

Patch

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 4b565a5b51da..40b52f1a071d 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -131,6 +131,18 @@  void iommufd_device_unbind(struct iommufd_device *idev)
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_device_unbind, IOMMUFD);
 
+struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev)
+{
+	return idev->ictx;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_device_to_ictx, IOMMUFD);
+
+u32 iommufd_device_to_id(struct iommufd_device *idev)
+{
+	return idev->obj.id;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_device_to_id, IOMMUFD);
+
 static int iommufd_device_setup_msi(struct iommufd_device *idev,
 				    struct iommufd_hw_pagetable *hwpt,
 				    phys_addr_t sw_msi_start)
@@ -480,6 +492,18 @@  void iommufd_access_destroy(struct iommufd_access *access)
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_destroy, IOMMUFD);
 
+struct iommufd_ctx *iommufd_access_to_ictx(struct iommufd_access *access)
+{
+	return access->ictx;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_access_to_ictx, IOMMUFD);
+
+u32 iommufd_access_to_id(struct iommufd_access *access)
+{
+	return access->obj.id;
+}
+EXPORT_SYMBOL_NS_GPL(iommufd_access_to_id, IOMMUFD);
+
 int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id)
 {
 	struct iommufd_ioas *new_ioas;
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index ca29c4feded3..54ac7be49b80 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -69,6 +69,30 @@  void vfio_iommufd_unbind(struct vfio_device *vdev)
 		vdev->ops->unbind_iommufd(vdev);
 }
 
+struct iommufd_ctx *vfio_iommufd_physical_ictx(struct vfio_device *vdev)
+{
+	if (vdev->iommufd_device)
+		return iommufd_device_to_ictx(vdev->iommufd_device);
+	if (vdev->iommufd_access)
+		return iommufd_access_to_ictx(vdev->iommufd_access);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_physical_ictx);
+
+/*
+ * Return devid for devices that have been bound with iommufd,
+ * returns 0 if not bound yet.
+ */
+u32 vfio_iommufd_physical_devid(struct vfio_device *vdev)
+{
+	if (WARN_ON(!vdev->iommufd_device && !vdev->iommufd_access))
+		return 0;
+	if (vdev->iommufd_device)
+		return iommufd_device_to_id(vdev->iommufd_device);
+	else
+		return iommufd_access_to_id(vdev->iommufd_access);
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_physical_devid);
 /*
  * The physical standard ops mean that the iommufd_device is bound to the
  * physical device vdev->dev that was provided to vfio_init_group_dev(). Drivers
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 1129a36a74c4..68cd65274e28 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -24,6 +24,9 @@  void iommufd_device_unbind(struct iommufd_device *idev);
 int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id);
 void iommufd_device_detach(struct iommufd_device *idev);
 
+struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev);
+u32 iommufd_device_to_id(struct iommufd_device *idev);
+
 struct iommufd_access_ops {
 	u8 needs_pin_pages : 1;
 	void (*unmap)(void *data, unsigned long iova, unsigned long length);
@@ -45,6 +48,9 @@  iommufd_access_create(struct iommufd_ctx *ictx,
 void iommufd_access_destroy(struct iommufd_access *access);
 int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id);
 
+struct iommufd_ctx *iommufd_access_to_ictx(struct iommufd_access *access);
+u32 iommufd_access_to_id(struct iommufd_access *access);
+
 void iommufd_ctx_get(struct iommufd_ctx *ictx);
 
 #if IS_ENABLED(CONFIG_IOMMUFD)
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 298f4ef16be7..cead7aebd527 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -116,6 +116,8 @@  struct vfio_device_ops {
 };
 
 #if IS_ENABLED(CONFIG_IOMMUFD)
+struct iommufd_ctx *vfio_iommufd_physical_ictx(struct vfio_device *vdev);
+u32 vfio_iommufd_physical_devid(struct vfio_device *vdev);
 int vfio_iommufd_physical_bind(struct vfio_device *vdev,
 			       struct iommufd_ctx *ictx, u32 *out_device_id);
 void vfio_iommufd_physical_unbind(struct vfio_device *vdev);
@@ -125,6 +127,18 @@  int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
 void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
 int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
 #else
+static inline struct iommufd_ctx *
+vfio_iommufd_physical_ictx(struct vfio_device *vdev)
+{
+	return NULL;
+}
+
+static inline u32
+vfio_iommufd_physical_devid(struct vfio_device *vdev)
+{
+	return 0;
+}
+
 #define vfio_iommufd_physical_bind                                      \
 	((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
 		  u32 *out_device_id)) NULL)