From 3e996cc58334be1c3f1be524b4f048566eccbb1d Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Fri, 29 Jan 2016 13:18:56 +0000 Subject: [PATCH] Fix virtio migration I misunderstood the vmstate macro definition when I reworked the virtio .get/.put. The VMSTATE_STRUCT_VARRAY_KNOWN, was described as being for "a variable length array (i.e. _type *_field) but we know the length". However it actually specified operation for arrays embedded in the struct (i.e. _type _field[]) since it lacked the VMS_POINTER flag. This caused offset calculation to be completely off, examining and potentially sending random data instead of the VirtQueue content. Replace the otherwise unused VMSTATE_STRUCT_VARRAY_KNOWN with a VMSTATE_STRUCT_VARRAY_POINTER_KNOWN that includes the VMS_POINTER flag (so now actually doing what it advertises) and use it in the virtio migration code. Fixes and description as per Sascha's suggestions/debug. Signed-off-by: Dr. David Alan Gilbert Reported-by: Sascha Silbe Tested-By: Sascha Silbe Reviewed-By: Sascha Silbe Fixes: 50e5ae4dc3e4f21e874512f9e87b93b5472d26e0 Fixes: 2cf0148674430b6693c60d42b7eef721bfa9509f Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Tested-by: Cornelia Huck --- hw/virtio/virtio.c | 8 ++++---- include/migration/vmstate.h | 18 +++++++++--------- 2 files changed, 13 insertions(+), 13 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 63a7b6d7ba..0603793e34 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1143,8 +1143,8 @@ static const VMStateDescription vmstate_virtio_virtqueues = { .minimum_version_id = 1, .needed = &virtio_virtqueue_needed, .fields = (VMStateField[]) { - VMSTATE_STRUCT_VARRAY_KNOWN(vq, struct VirtIODevice, VIRTIO_QUEUE_MAX, - 0, vmstate_virtqueue, VirtQueue), + VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, + VIRTIO_QUEUE_MAX, 0, vmstate_virtqueue, VirtQueue), VMSTATE_END_OF_LIST() } }; @@ -1165,8 +1165,8 @@ static const VMStateDescription vmstate_virtio_ringsize = { .minimum_version_id = 1, .needed = &virtio_ringsize_needed, .fields = (VMStateField[]) { - VMSTATE_STRUCT_VARRAY_KNOWN(vq, struct VirtIODevice, VIRTIO_QUEUE_MAX, - 0, vmstate_ringsize, VirtQueue), + VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(vq, struct VirtIODevice, + VIRTIO_QUEUE_MAX, 0, vmstate_ringsize, VirtQueue), VMSTATE_END_OF_LIST() } }; diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index a4b81bb5f6..7246f29afe 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -386,26 +386,26 @@ extern const VMStateInfo vmstate_info_bitmap; .offset = vmstate_offset_array(_state, _field, _type, _num),\ } -/* a variable length array (i.e. _type *_field) but we know the - * length - */ -#define VMSTATE_STRUCT_VARRAY_KNOWN(_field, _state, _num, _version, _vmsd, _type) { \ +#define VMSTATE_STRUCT_VARRAY_UINT8(_field, _state, _field_num, _version, _vmsd, _type) { \ .name = (stringify(_field)), \ - .num = (_num), \ + .num_offset = vmstate_offset_value(_state, _field_num, uint8_t), \ .version_id = (_version), \ .vmsd = &(_vmsd), \ .size = sizeof(_type), \ - .flags = VMS_STRUCT|VMS_ARRAY, \ + .flags = VMS_STRUCT|VMS_VARRAY_UINT8, \ .offset = offsetof(_state, _field), \ } -#define VMSTATE_STRUCT_VARRAY_UINT8(_field, _state, _field_num, _version, _vmsd, _type) { \ +/* a variable length array (i.e. _type *_field) but we know the + * length + */ +#define VMSTATE_STRUCT_VARRAY_POINTER_KNOWN(_field, _state, _num, _version, _vmsd, _type) { \ .name = (stringify(_field)), \ - .num_offset = vmstate_offset_value(_state, _field_num, uint8_t), \ + .num = (_num), \ .version_id = (_version), \ .vmsd = &(_vmsd), \ .size = sizeof(_type), \ - .flags = VMS_STRUCT|VMS_VARRAY_UINT8, \ + .flags = VMS_STRUCT|VMS_ARRAY|VMS_POINTER, \ .offset = offsetof(_state, _field), \ } -- 2.34.1