From: Sebastien Boeuf <[email protected]>
This series introduces a new operation for vdpa devices. It allows them
to be resumed after they have been suspended. A new feature bit is
introduced for devices to advertise their ability to be resumed after
they have been suspended. This feature bit is different from the one
advertising the ability to be suspended, meaning a device that can be
suspended might not have the ability to be resumed.
Even if it is already possible to restore a device that has been
suspended, which is very convenient for live migrating virtual machines,
there is a major drawback as the device must be fully reset. There is no
way to resume a device that has been suspended without having to
configure the device again and without having to recreate the IOMMU
mappings. This new operation aims at filling this gap by allowing the
device to resume processing the virtqueue descriptors without having to
reset it. This is particularly useful for performing virtual machine
offline migration, also called snapshot/restore, as it allows a virtual
machine to resume to a running state after it was paused and a snapshot
of the entire system was taken.
Sebastien Boeuf (4):
vdpa: Add resume operation
vhost-vdpa: Introduce RESUME backend feature bit
vhost-vdpa: uAPI to resume the device
vdpa_sim: Implement resume vdpa op
drivers/vdpa/vdpa_sim/vdpa_sim.c | 28 ++++++++++++++++++++++++++
drivers/vdpa/vdpa_sim/vdpa_sim.h | 1 +
drivers/vhost/vdpa.c | 34 +++++++++++++++++++++++++++++++-
include/linux/vdpa.h | 6 +++++-
include/uapi/linux/vhost.h | 8 ++++++++
include/uapi/linux/vhost_types.h | 2 ++
6 files changed, 77 insertions(+), 2 deletions(-)
--
2.34.1
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From: Sebastien Boeuf <[email protected]>
Add a new operation to allow a vDPA device to be resumed after it has
been suspended. Trying to resume a device that wasn't suspended will
result in a no-op.
This operation is optional. If it's not implemented, the associated
backend feature bit will not be exposed. And if the feature bit is not
exposed, invoking this operation will return an error.
Acked-by: Jason Wang <[email protected]>
Signed-off-by: Sebastien Boeuf <[email protected]>
---
include/linux/vdpa.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 6d0f5e4e82c2..96d308cbf97b 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -219,7 +219,10 @@ struct vdpa_map_file {
* @reset: Reset device
* @vdev: vdpa device
* Returns integer: success (0) or error (< 0)
- * @suspend: Suspend or resume the device (optional)
+ * @suspend: Suspend the device (optional)
+ * @vdev: vdpa device
+ * Returns integer: success (0) or error (< 0)
+ * @resume: Resume the device (optional)
* @vdev: vdpa device
* Returns integer: success (0) or error (< 0)
* @get_config_size: Get the size of the configuration space includes
@@ -324,6 +327,7 @@ struct vdpa_config_ops {
void (*set_status)(struct vdpa_device *vdev, u8 status);
int (*reset)(struct vdpa_device *vdev);
int (*suspend)(struct vdpa_device *vdev);
+ int (*resume)(struct vdpa_device *vdev);
size_t (*get_config_size)(struct vdpa_device *vdev);
void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
void *buf, unsigned int len);
--
2.34.1
---------------------------------------------------------------------
Intel Corporation SAS (French simplified joint stock company)
Registered headquarters: "Les Montalets"- 2, rue de Paris,
92196 Meudon Cedex, France
Registration Number: 302 456 199 R.C.S. NANTERRE
Capital: 5 208 026.16 Euros
This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.