[PATCH v2 06/10] vfio: Refine vfio file kAPIs for vfio PCI hot reset

Yi Liu
2023-03-27T09:35:53Z

This prepares vfio core to accept vfio device file from the vfio PCI
hot reset path. vfio_file_is_group() is still kept for KVM usage.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/vfio/group.c | 32 ++++++++++++++------------------
drivers/vfio/pci/vfio_pci_core.c | 4 ++--
drivers/vfio/vfio.h | 2 ++
drivers/vfio/vfio_main.c | 29 +++++++++++++++++++++++++++++
include/linux/vfio.h | 1 +
5 files changed, 48 insertions(+), 20 deletions(-)

diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index 27d5ba7cf9dc..d0c95d033605 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -745,6 +745,15 @@ bool vfio_device_has_container(struct vfio_device *device)
return device->group->container;
}

+struct vfio_group *vfio_group_from_file(struct file *file)
+{
+ struct vfio_group *group = file->private_data;
+
+ if (file->f_op != &vfio_group_fops)
+ return NULL;
+ return group;
+}
+
/**
* vfio_file_iommu_group - Return the struct iommu_group for the vfio group file
* @file: VFIO group file
@@ -755,13 +764,13 @@ bool vfio_device_has_container(struct vfio_device *device)
*/
struct iommu_group *vfio_file_iommu_group(struct file *file)
{
- struct vfio_group *group = file->private_data;
+ struct vfio_group *group = vfio_group_from_file(file);
struct iommu_group *iommu_group = NULL;

if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
return NULL;

- if (!vfio_file_is_group(file))
+ if (!group)
return NULL;

mutex_lock(&group->group_lock);
@@ -775,12 +784,12 @@ struct iommu_group *vfio_file_iommu_group(struct file *file)
EXPORT_SYMBOL_GPL(vfio_file_iommu_group);

/**
- * vfio_file_is_group - True if the file is usable with VFIO aPIS
+ * vfio_file_is_group - True if the file is a vfio group file
* @file: VFIO group file
*/
bool vfio_file_is_group(struct file *file)
{
- return file->f_op == &vfio_group_fops;
+ return vfio_group_from_file(file);
}
EXPORT_SYMBOL_GPL(vfio_file_is_group);

@@ -842,23 +851,10 @@ void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
}
EXPORT_SYMBOL_GPL(vfio_file_set_kvm);

-/**
- * vfio_file_has_dev - True if the VFIO file is a handle for device
- * @file: VFIO file to check
- * @device: Device that must be part of the file
- *
- * Returns true if given file has permission to manipulate the given device.
- */
-bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
+bool vfio_group_has_dev(struct vfio_group *group, struct vfio_device *device)
{
- struct vfio_group *group = file->private_data;
-
- if (!vfio_file_is_group(file))
- return false;
-
return group == device->group;
}
-EXPORT_SYMBOL_GPL(vfio_file_has_dev);

static char *vfio_devnode(const struct device *dev, umode_t *mode)
{
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index b68fcba67a4b..2a510b71edcb 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1308,8 +1308,8 @@ vfio_pci_ioctl_pci_hot_reset_groups(struct vfio_pci_core_device *vdev,
break;
}

- /* Ensure the FD is a vfio group FD.*/
- if (!vfio_file_is_group(file)) {
+ /* Ensure the FD is a vfio FD. vfio group or vfio device */
+ if (!vfio_file_is_valid(file)) {
fput(file);
ret = -EINVAL;
break;
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index 7b19c621e0e6..c0aeea24fbd6 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -84,6 +84,8 @@ void vfio_device_group_unregister(struct vfio_device *device);
int vfio_device_group_use_iommu(struct vfio_device *device);
void vfio_device_group_unuse_iommu(struct vfio_device *device);
void vfio_device_group_close(struct vfio_device *device);
+struct vfio_group *vfio_group_from_file(struct file *file);
+bool vfio_group_has_dev(struct vfio_group *group, struct vfio_device *device);
bool vfio_device_has_container(struct vfio_device *device);
int __init vfio_group_init(void);
void vfio_group_cleanup(void);
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 89497c933490..fe7446805afd 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -1154,6 +1154,35 @@ const struct file_operations vfio_device_fops = {
.mmap = vfio_device_fops_mmap,
};

+/**
+ * vfio_file_is_valid - True if the file is valid vfio file
+ * @file: VFIO group file or VFIO device file
+ */
+bool vfio_file_is_valid(struct file *file)
+{
+ return vfio_group_from_file(file);
+}
+EXPORT_SYMBOL_GPL(vfio_file_is_valid);
+
+/**
+ * vfio_file_has_dev - True if the VFIO file is a handle for device
+ * @file: VFIO file to check
+ * @device: Device that must be part of the file
+ *
+ * Returns true if given file has permission to manipulate the given device.
+ */
+bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
+{
+ struct vfio_group *group;
+
+ group = vfio_group_from_file(file);
+ if (!group)
+ return false;
+
+ return vfio_group_has_dev(group, device);
+}
+EXPORT_SYMBOL_GPL(vfio_file_has_dev);
+
/*
* Sub-module support
*/
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index e54bef5489a0..79c47733ae0d 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -258,6 +258,7 @@ int vfio_mig_get_next_state(struct vfio_device *device,
*/
struct iommu_group *vfio_file_iommu_group(struct file *file);
bool vfio_file_is_group(struct file *file);
+bool vfio_file_is_valid(struct file *file);
bool vfio_file_enforced_coherent(struct file *file);
void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
bool vfio_file_has_dev(struct file *file, struct vfio_device *device);
--
2.34.1