Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1163143

[v4 10/16] KVM: kvm-vfio: wrappers to VFIO external API device helpers

Show all headers | View raw

From: Eric Auger <eric.auger@linaro.org>

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.

Also kvm_vfio_get_vfio_device and kvm_vfio_put_vfio_device helpers
are introduced.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
---
 virt/kvm/vfio.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 620e37f..80a45e4 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -60,6 +60,80 @@ static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group)
 	symbol_put(vfio_group_put_external_user);
 }
 
+static 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;
+}
+
+static 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);
+}
+
+static 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;
+}
+
+/**
+ * kvm_vfio_get_vfio_device - Returns a handle to a vfio-device
+ *
+ * Checks it is a valid vfio device and increments its reference counter
+ * @fd: file descriptor of the vfio platform device
+ */
+static struct vfio_device *kvm_vfio_get_vfio_device(int fd)
+{
+	struct fd f = fdget(fd);
+	struct vfio_device *vdev;
+
+	if (!f.file)
+		return ERR_PTR(-EINVAL);
+	vdev = kvm_vfio_device_get_external_user(f.file);
+	fdput(f);
+	return vdev;
+}
+
+/**
+ * kvm_vfio_put_vfio_device: decrements the reference counter of the
+ * vfio platform * device
+ *
+ * @vdev: vfio_device handle to release
+ */
+static void kvm_vfio_put_vfio_device(struct vfio_device *vdev)
+{
+	kvm_vfio_device_put_external_user(vdev);
+}
+
 static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group)
 {
 	long (*fn)(struct vfio_group *, unsigned long);
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[v4 00/16] Add VT-d Posted-Interrupts support Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 12/16] KVM: kvm-vfio: implement the VFIO skeleton for VT-d Posted-Interrupts Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
    RE: [v4 12/16] KVM: kvm-vfio: implement the VFIO skeleton for VT-d  Posted-Interrupts "Wu, Feng" <feng.wu@intel.com> - 2015-06-12 07:00 +0200
  [v4 13/16] KVM: x86: kvm-vfio: VT-d posted-interrupts setup Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
    RE: [v4 13/16] KVM: x86: kvm-vfio: VT-d posted-interrupts setup "Wu, Feng" <feng.wu@intel.com> - 2015-06-12 07:00 +0200
  [v4 15/16] KVM: Update Posted-Interrupts Descriptor when vCPU is blocked Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 07/16] KVM: make kvm_set_msi_irq() public Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 10/16] KVM: kvm-vfio: wrappers to VFIO external API device helpers Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 11/16] KVM: kvm-vfio: User API for VT-d Posted-Interrupts Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 05/16] KVM: Add interfaces to control PI outside vmx Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 14/16] KVM: Update Posted-Interrupts Descriptor when vCPU is preempted Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 02/16] KVM: Add some helper functions for Posted-Interrupts Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 16/16] KVM: Warn if 'SN' is set during posting interrupts by software Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 04/16] KVM: Get Posted-Interrupts descriptor address from struct kvm_vcpu Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 01/16] KVM: Extend struct pi_desc for VT-d Posted-Interrupts Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200
  [v4 09/16] VFIO: external user API for interaction Feng Wu <feng.wu@intel.com> - 2015-06-11 13:10 +0200

csiph-web