17.05.2021 18:48, Max Reitz wrote:
On 17.05.21 08:44, Vladimir Sementsov-Ogievskiy wrote:
We need an ability to insert filters above top block node, attached to
block device. It can't be achieved with blockdev-reopen command. So, we
want do it with help of qom-set.
Intended usage:
1. blockdev-add, creating the filter, which child is at top node A,
attached to some guest block device.
Is a “not” missing here, i.e. “not attached to any guest block device”? I
would have thought one would create a filtered tree that is not in use by any
frontend, so that the filter need not take any permissions.
node A is attached.
So, we have [blk] --root-> [A}
And want to insert a filter between blk and A.
We do
1.
[filter] --file--\
v
[blk] --root--> [A]
2.
[blk] --root--> [filer] --file--> [A]
2. qom-set, to change bs attached to root blk from original node to
newly create filter.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
hw/core/qdev-properties-system.c | 30 ++++++++++++++++++++++--------
1 file changed, 22 insertions(+), 8 deletions(-)
Looks good, just one question: (well, two, one was above)
diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index 2760c21f11..7d97562654 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
[...]
@@ -196,6 +209,7 @@ static void release_drive(Object *obj, const char *name,
void *opaque)
const PropertyInfo qdev_prop_drive = {
.name = "str",
.description = "Node name or ID of a block device to use as a backend",
+ .realized_set_allowed = true,
.get = get_drive,
.set = set_drive,
.release = release_drive,
Why not for qdev_prop_drive_iothread?
Hmm, the only reason is that I missed that part of architecture around here,
I'm new to qdev code. Will add with next version
--
Best regards,
Vladimir
