Re: [PATCH V4 1/2] migration: file URI

[Daniel P . Berrangé]

On Wed, Aug 30, 2023 at 10:15:43AM -0400, Steven Sistare wrote:
> On 8/30/2023 9:16 AM, Daniel P. Berrangé wrote:
> > On Fri, Jun 30, 2023 at 07:25:07AM -0700, Steve Sistare wrote:
> >> Extend the migration URI to support file:<filename>.  This can be used for
> >> any migration scenario that does not require a reverse path.  It can be
> >> used as an alternative to 'exec:cat > file' in minimized containers that
> >> do not contain /bin/sh, and it is easier to use than the fd:<fdname> URI.
> >> It can be used in HMP commands, and as a qemu command-line parameter.
> >>
> >> For best performance, guest ram should be shared and x-ignore-shared
> >> should be true, so guest pages are not written to the file, in which case
> >> the guest may remain running.  If ram is not so configured, then the user
> >> is advised to stop the guest first.  Otherwise, a busy guest may re-dirty
> >> the same page, causing it to be appended to the file multiple times,
> >> and the file may grow unboundedly.  That issue is being addressed in the
> >> "fixed-ram" patch series.
> >>
> >> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
> >> Reviewed-by: Fabiano Rosas <farosas@suse.de>
> >> Reviewed-by: Peter Xu <peterx@redhat.com>
> >> ---
> >>  migration/file.c       | 62 
> >> ++++++++++++++++++++++++++++++++++++++++++++++++++
> >>  migration/file.h       | 14 ++++++++++++
> >>  migration/meson.build  |  1 +
> >>  migration/migration.c  |  5 ++++
> >>  migration/trace-events |  4 ++++
> >>  qemu-options.hx        |  6 ++++-
> >>  6 files changed, 91 insertions(+), 1 deletion(-)
> >>  create mode 100644 migration/file.c
> >>  create mode 100644 migration/file.h
> >>
> >> diff --git a/migration/file.c b/migration/file.c
> >> new file mode 100644
> >> index 0000000..8e35827
> >> --- /dev/null
> >> +++ b/migration/file.c
> >> @@ -0,0 +1,62 @@
> >> +/*
> >> + * Copyright (c) 2021-2023 Oracle and/or its affiliates.
> >> + *
> >> + * This work is licensed under the terms of the GNU GPL, version 2.
> > 
> > Was it an intentional decision to assign this under the version 2 *only* ?
> > 
> > QEMU's LICENSE file states
> > 
> > [quote]
> > As of July 2013, contributions under version 2 of the GNU General Public
> > License (and no later version) are only accepted for the following files
> > or directories: bsd-user/, linux-user/, hw/vfio/, hw/xen/xen_pt*.
> > [/quote]
> > 
> > Thus we'd expect this new file to be version 2, or later.
> 
> My mistake, sorry.  It should say "GNU GPL, version 2 or later"

Could you re-post, as aside from that, this series looks
ready for merge.


With regards,
Daniel
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