On Mon, Jun 03, 2019 at 02:05:47PM +0800, Wei Yang wrote: >On Mon, Jun 03, 2019 at 01:40:13PM +0800, Peter Xu wrote: >> >>Ah I see, thanks for the pointer. Then I would agree it's fine. >> >>I'm not an expert of TCG - I'm curious on why all those three dirty >>bitmaps need to be set at the very beginning. IIUC at least the VGA >>bitmap should not require that (so IMHO we should be fine to have all >>zeros with VGA bitmap for ramblocks, and we only set them when the >>guest touches them). Migration bitmap should be special somehow but I >>don't know much on TCG/TLB part I'd confess so I can't say. In other >>words, if migration is the only one that requires this "all-1" >>initialization then IMHO we may consider to remove the other part >>rather than here in migration because that's what we'd better to be >>sure with. > >I am not sure about the background here, so I didn't make a change at this >place. > >> >>And even if you want to remove this, I still have two suggestions: >> >>(1) proper comment here above bmap on the above fact that although >> bmap is not set here but it's actually set somewhere else because >> we'll sooner or later copy all 1s from the ramblock bitmap >> >>(2) imho you can move "migration_dirty_pages = 0" into >> ram_list_init_bitmaps() too to let them be together >>
I took a look into this one. ram_list_init_bitmaps() setup bitmap for each RAMBlock, while ram_state_init() setup RAMState. Since migration_dirty_pages belongs to RAMState, it maybe more proper to leave it at the original place. Do you feel good about this? > >I will address these two comments and send v2. > >Thanks. > >>-- >>Peter Xu > >-- >Wei Yang >Help you, Help me -- Wei Yang Help you, Help me
