Provide wrapper functions that allow KVM-VFIO device code to
interact with a vfio device:
- kvm_vfio_device_get_external_user gets a handle to a struct
vfio_device from the vfio device file descriptor and increments
its reference counter,
- kvm_vfio_device_put_external_user decrements the reference counter
to a vfio device,
- kvm_vfio_external_base_device returns a handle to the struct device
of the vfio device.
The KVM-VFIO device uses the VFIO external API device functions.
Signed-off-by: Eric Auger <eric.au...@linaro.org>
---
v2 -> v3:
reword the commit message and title
v1 -> v2:
- kvm_vfio_external_get_base_device renamed into
kvm_vfio_external_base_device
- kvm_vfio_external_get_type removed
---
arch/arm/include/asm/kvm_host.h | 5 +++++
virt/kvm/vfio.c | 45 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 50 insertions(+)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 53036e2..bca5b79 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -169,6 +169,11 @@ void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva,
pte_t pte);
unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu);
int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices);
+struct vfio_device;
+struct vfio_device *kvm_vfio_device_get_external_user(struct file *filep);
+void kvm_vfio_device_put_external_user(struct vfio_device *vdev);
+struct device *kvm_vfio_external_base_device(struct vfio_device *vdev);
+
/* We do not have shadow page tables, hence the empty hooks */
static inline int kvm_age_hva(struct kvm *kvm, unsigned long start,
unsigned long end)
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 620e37f..6f0cc34 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -60,6 +60,51 @@ static void kvm_vfio_group_put_external_user(struct
vfio_group *vfio_group)
symbol_put(vfio_group_put_external_user);
}
+struct vfio_device *kvm_vfio_device_get_external_user(struct file *filep)
+{
+ struct vfio_device *vdev;
+ struct vfio_device *(*fn)(struct file *);
+
+ fn = symbol_get(vfio_device_get_external_user);
+ if (!fn)
+ return ERR_PTR(-EINVAL);
+
+ vdev = fn(filep);
+
+ symbol_put(vfio_device_get_external_user);
+
+ return vdev;
+}
+
+void kvm_vfio_device_put_external_user(struct vfio_device *vdev)
+{
+ void (*fn)(struct vfio_device *);
+
+ fn = symbol_get(vfio_device_put_external_user);
+ if (!fn)
+ return;
+
+ fn(vdev);
+
+ symbol_put(vfio_device_put_external_user);
+}
+
+struct device *kvm_vfio_external_base_device(struct vfio_device *vdev)
+{
+ struct device *(*fn)(struct vfio_device *);
+ struct device *dev;
+
+ fn = symbol_get(vfio_external_base_device);
+ if (!fn)
+ return NULL;
+
+ dev = fn(vdev);
+
+ symbol_put(vfio_external_base_device);
+
+ return dev;
+}
+
static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group)
{
long (*fn)(struct vfio_group *, unsigned long);
--
1.9.1
--
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