|
From: | Vladimir Sementsov-Ogievskiy |
Subject: | Re: [Qemu-devel] [PATCH RFC v2 8/8] migration: add migration/dirty-bitmap.c |
Date: | Tue, 17 Feb 2015 11:54:37 +0300 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 |
On 16.02.2015 21:18, John Snow wrote:
On 02/16/2015 07:06 AM, Vladimir Sementsov-Ogievskiy wrote:On 13.02.2015 23:22, John Snow wrote:On 02/13/2015 03:19 AM, Vladimir Sementsov-Ogievskiy wrote:On 11.02.2015 00:33, John Snow wrote:
Hmm.. No? bitmap is attached using bdrv_lookup_bs(name, name, errp), which can find device with this name. qemu option -drive file=...,id=disk creates blk named 'disk' and attached node with no name.So in summary: using device names is probably fine for now, as it matches the current use case of bitmaps as well as drive migration; but using node names may give us more power and precision later. I talked to Max about it, and he is leaning towards using device names for now and switching to node names if we decide we want that power. (...I wonder if we could use a flag, for now, that says we're including DEVICE names. Later, we could add a flag that says we'reusing NODE names and add an option to toggle as the usage case sees fit.)Are you confused yet? :DO, thanks for the explanation). Are we really need this flag? As Markus wrote, nodes and devices are sharing namespaces.. We can use bdrv_lookup_bs(name, name, errp)..what 'name' are you using here, though? It looked to me like in your backup routine we got a list of BDS entries and get the name *from* the BDS, so we still have to think about how we want to /get/ the name.Also, we can, for example, send bitmaps as follows: if node has name - send bitmap with this name if node is root, but hasn't name - send it with blk name otherwise - don't send the bitmapThe node a bitmap is attached to should always have a name -- it would not be possible via the existing interface to attach it to a node without a name.I *think* the root node should always have a name, but I am actually less sure of that.
-- Best regards, Vladimir
[Prev in Thread] | Current Thread | [Next in Thread] |