[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC v2 28/32] postcopy: Allow shared memory
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [RFC v2 28/32] postcopy: Allow shared memory |
Date: |
Thu, 7 Sep 2017 13:15:34 +0100 |
User-agent: |
Mutt/1.8.3 (2017-05-23) |
* Marc-André Lureau (address@hidden) wrote:
> Hi
>
> On Thu, Aug 24, 2017 at 12:27 PM, Dr. David Alan Gilbert (git)
> <address@hidden> wrote:
> > From: "Dr. David Alan Gilbert" <address@hidden>
> >
> > Now that we have the mechanisms in here, allow shared memory in a
> > postcopy.
> >
> > Note that QEMU can't tell who all the users of shared regions are
> > and thus can't tell whether all the users of the shared regions
> > have appropriate support for postcopy. Those devices that explicitly
> > support shared memory (e.g. vhost-user) must check, but it doesn't
> > stop weirder configurations causing problems.
> >
>
> Other users should have their own migration blocker, I guess.
Yes, the ones that know about it.
The tricky thing is you can add a shared=on to any memory object you
add; I don't know that the reason it's shared is purely because it's
used by vhost-user - for all qemu knows it could be shared with 5 other
things as well.
> > Signed-off-by: Dr. David Alan Gilbert <address@hidden>
>
> Reviewed-by: Marc-André Lureau <address@hidden>
Thanks.
Dave
>
>
> > ---
> > migration/postcopy-ram.c | 6 ------
> > 1 file changed, 6 deletions(-)
> >
> > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> > index 28791cf1f1..89c3aadda1 100644
> > --- a/migration/postcopy-ram.c
> > +++ b/migration/postcopy-ram.c
> > @@ -138,12 +138,6 @@ static int test_ramblock_postcopiable(const char
> > *block_name, void *host_addr,
> > RAMBlock *rb = qemu_ram_block_by_name(block_name);
> > size_t pagesize = qemu_ram_pagesize(rb);
> >
> > - if (qemu_ram_is_shared(rb)) {
> > - error_report("Postcopy on shared RAM (%s) is not yet supported",
> > - block_name);
> > - return 1;
> > - }
> > -
> > if (length % pagesize) {
> > error_report("Postcopy requires RAM blocks to be a page size
> > multiple,"
> > " block %s is 0x" RAM_ADDR_FMT " bytes with a "
> > --
> > 2.13.5
> >
> >
>
>
>
> --
> Marc-André Lureau
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- Re: [Qemu-devel] [RFC v2 28/32] postcopy: Allow shared memory,
Dr. David Alan Gilbert <=