[Intel-gfx] [PATCH v9 02/25] vfio: Refine vfio file kAPIs for KVM
Yi Liu
yi.l.liu at intel.com
Sat Apr 1 15:18:10 UTC 2023
This prepares for making the below kAPIs to accept both group file
and device file instead of only vfio group file.
bool vfio_file_enforced_coherent(struct file *file);
void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
Reviewed-by: Kevin Tian <kevin.tian at intel.com>
Reviewed-by: Eric Auger <eric.auger at redhat.com>
Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>
Tested-by: Terrence Xu <terrence.xu at intel.com>
Tested-by: Nicolin Chen <nicolinc at nvidia.com>
Tested-by: Matthew Rosato <mjrosato at linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang at intel.com>
Signed-off-by: Yi Liu <yi.l.liu at intel.com>
---
drivers/vfio/group.c | 36 ++++++---------------------------
drivers/vfio/vfio.h | 2 ++
drivers/vfio/vfio_main.c | 43 ++++++++++++++++++++++++++++++++++++++++
virt/kvm/vfio.c | 10 +++++-----
4 files changed, 56 insertions(+), 35 deletions(-)
diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index 8a13cea43f49..ede4723c5f72 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -802,24 +802,11 @@ bool vfio_file_is_group(struct file *file)
}
EXPORT_SYMBOL_GPL(vfio_file_is_group);
-/**
- * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
- * is always CPU cache coherent
- * @file: VFIO group file
- *
- * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
- * bit in DMA transactions. A return of false indicates that the user has
- * rights to access additional instructions such as wbinvd on x86.
- */
-bool vfio_file_enforced_coherent(struct file *file)
+bool vfio_group_enforced_coherent(struct vfio_group *group)
{
- struct vfio_group *group = file->private_data;
struct vfio_device *device;
bool ret = true;
- if (!vfio_file_is_group(file))
- return true;
-
/*
* If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then
* any domain later attached to it will also not support it. If the cap
@@ -837,28 +824,17 @@ bool vfio_file_enforced_coherent(struct file *file)
mutex_unlock(&group->device_lock);
return ret;
}
-EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
-/**
- * vfio_file_set_kvm - Link a kvm with VFIO drivers
- * @file: VFIO group file
- * @kvm: KVM to link
- *
- * When a VFIO device is first opened the KVM will be available in
- * device->kvm if one was associated with the group.
- */
-void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
{
- struct vfio_group *group = file->private_data;
-
- if (!vfio_file_is_group(file))
- return;
-
+ /*
+ * When a VFIO device is first opened the KVM will be available in
+ * device->kvm if one was associated with the group.
+ */
spin_lock(&group->kvm_ref_lock);
group->kvm = kvm;
spin_unlock(&group->kvm_ref_lock);
}
-EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
bool vfio_group_has_dev(struct vfio_group *group, struct vfio_device *device)
{
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index 250fbd3786c5..56ad127ac618 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -92,6 +92,8 @@ 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_group_enforced_coherent(struct vfio_group *group);
+void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
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 89722bf87edc..748bde4d74d9 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -1219,6 +1219,49 @@ bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
}
EXPORT_SYMBOL_GPL(vfio_file_has_dev);
+/**
+ * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
+ * is always CPU cache coherent
+ * @file: VFIO group file or VFIO device file
+ *
+ * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
+ * bit in DMA transactions. A return of false indicates that the user has
+ * rights to access additional instructions such as wbinvd on x86.
+ */
+bool vfio_file_enforced_coherent(struct file *file)
+{
+ struct vfio_group *group;
+ struct vfio_device *device;
+
+ group = vfio_group_from_file(file);
+ if (group)
+ return vfio_group_enforced_coherent(group);
+
+ device = vfio_device_from_file(file);
+ if (device)
+ return device_iommu_capable(device->dev,
+ IOMMU_CAP_ENFORCE_CACHE_COHERENCY);
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
+
+/**
+ * vfio_file_set_kvm - Link a kvm with VFIO drivers
+ * @file: VFIO group file or VFIO device file
+ * @kvm: KVM to link
+ *
+ */
+void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+{
+ struct vfio_group *group;
+
+ group = vfio_group_from_file(file);
+ if (group)
+ vfio_group_set_kvm(group, kvm);
+}
+EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
+
/*
* Sub-module support
*/
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 9584eb57e0ed..8bac308ba630 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -64,18 +64,18 @@ static bool kvm_vfio_file_enforced_coherent(struct file *file)
return ret;
}
-static bool kvm_vfio_file_is_group(struct file *file)
+static bool kvm_vfio_file_is_valid(struct file *file)
{
bool (*fn)(struct file *file);
bool ret;
- fn = symbol_get(vfio_file_is_group);
+ fn = symbol_get(vfio_file_is_valid);
if (!fn)
return false;
ret = fn(file);
- symbol_put(vfio_file_is_group);
+ symbol_put(vfio_file_is_valid);
return ret;
}
@@ -154,8 +154,8 @@ static int kvm_vfio_group_add(struct kvm_device *dev, unsigned int fd)
if (!filp)
return -EBADF;
- /* Ensure the FD is a vfio group FD.*/
- if (!kvm_vfio_file_is_group(filp)) {
+ /* Ensure the FD is a vfio FD.*/
+ if (!kvm_vfio_file_is_valid(filp)) {
ret = -EINVAL;
goto err_fput;
}
--
2.34.1
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