motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-04 00:03:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

vhost: switch to use IOTLB v2 format

Browse source 
This patch tries to switch to use new kernel IOTLB format V2. Previous
version may have inconsistent ABI between 32bit and 64bit machines
because of the hole after type field. Refer kernel commit
("429711aec282 vhost: switch to use new message format") for more
information.

To enable this feature, qemu need to use a new ioctl
VHOST_SET_BACKEND_FEATURE with VHOST_BACKEND_F_IOTLB_MSG_V2 bit. A new
vhost setting backend features ops was introduced. And when we try to
set features for vhost dev, we will examine the support of new IOTLB
format and enable it. This process is total transparent to guest,
which means we can have different IOTLB message type in src and dst
during migration.

The conversion of IOTLB message is straightforward, just check the
type and behave accordingly.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20200907104903.31551-3-jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Jason Wang 2020-09-07 18:49:02 +08:00 • committed by Michael S. Tsirkin
parent e6546342a8
commit b37556edec
4 changed files with 84 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files

2
include/hw/virtio/vhost-backend.h
View file

@ -74,6 +74,7 @@ typedef int (*vhost_set_features_op)(struct vhost_dev *dev,
uint64_t features);
typedef int (*vhost_get_features_op)(struct vhost_dev *dev,
uint64_t *features);
typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
@ -146,6 +147,7 @@ typedef struct VhostOps {
vhost_set_vring_busyloop_timeout_op vhost_set_vring_busyloop_timeout;
vhost_set_features_op vhost_set_features;
vhost_get_features_op vhost_get_features;
vhost_set_backend_cap_op vhost_set_backend_cap;
vhost_set_owner_op vhost_set_owner;
vhost_reset_device_op vhost_reset_device;
vhost_get_vq_index_op vhost_get_vq_index;