Commit 5bfe37ca authored by Sebastien Boeuf's avatar Sebastien Boeuf Committed by Miklos Szeredi
Browse files

virtio: Add get_shm_region method 



Virtio defines 'shared memory regions' that provide a continuously
shared region between the host and guest.

Provide a method to find a particular region on a device.

Signed-off-by: default avatarSebastien Boeuf <sebastien.boeuf@intel.com>
Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Cc: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 9123e3a7

include/linux/virtio_config.h

+17 −0
Original line number Diff line number Diff line
@@ -11,6 +11,11 @@ 


struct irq_affinity;



struct virtio_shm_region {

	u64 addr;

	u64 len;

};



/**

 * virtio_config_ops - operations for configuring a virtio device

 * Note: Do not assume that a transport implements all of the operations
@@ -66,6 +71,7 @@ struct irq_affinity; 
 *      the caller can then copy.

 * @set_vq_affinity: set the affinity for a virtqueue (optional).

 * @get_vq_affinity: get the affinity for a virtqueue (optional).

 * @get_shm_region: get a shared memory region based on the index.

 */

typedef void vq_callback_t(struct virtqueue *);

struct virtio_config_ops {
@@ -89,6 +95,8 @@ struct virtio_config_ops { 
			       const struct cpumask *cpu_mask);

	const struct cpumask *(*get_vq_affinity)(struct virtio_device *vdev,

			int index);

	bool (*get_shm_region)(struct virtio_device *vdev,

			       struct virtio_shm_region *region, u8 id);

};



/* If driver didn't advertise the feature, it will never appear. */
@@ -251,6 +259,15 @@ int virtqueue_set_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask) 
	return 0;

}



static inline

bool virtio_get_shm_region(struct virtio_device *vdev,

			   struct virtio_shm_region *region, u8 id)

{

	if (!vdev->config->get_shm_region)

		return false;

	return vdev->config->get_shm_region(vdev, region, id);

}



static inline bool virtio_is_little_endian(struct virtio_device *vdev)

{

	return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||

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