From b37556edec8372bef83959901fc142a272a7e1fa Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Mon, 7 Sep 2020 18:49:02 +0800 Subject: vhost: switch to use IOTLB v2 format 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 Message-Id: <20200907104903.31551-3-jasowang@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- include/hw/virtio/vhost-backend.h | 2 ++ include/hw/virtio/vhost.h | 1 + 2 files changed, 3 insertions(+) (limited to 'include') diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h index 8825bd2..8a6f8e2 100644 --- a/include/hw/virtio/vhost-backend.h +++ b/include/hw/virtio/vhost-backend.h @@ -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; diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index 767a95e..9458506 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -79,6 +79,7 @@ struct vhost_dev { uint64_t backend_features; uint64_t protocol_features; uint64_t max_queues; + uint64_t backend_cap; bool started; bool log_enabled; uint64_t log_size; -- cgit v1.1