Re: [Qemu-devel] [PULL 00/24] qemu-ga patch queue for soft-freeze

[Michael Roth]

Quoting Peter Maydell (2018-10-30 13:49:18)
> On 30 October 2018 at 14:43, Michael Roth <address@hidden> wrote:
> > The following changes since commit 62b658db1df7c6fa574caae038144f24bf6ca495:
> >
> >   Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' 
> > into staging (2018-10-29 17:03:27 +0000)
> >
> > are available in the Git repository at:
> >
> >   git://github.com/mdroth/qemu.git tags/qga-pull-2018-10-30-tag
> >
> > for you to fetch changes up to 86f167a2326cebec947da6526dae0a356148bd8a:
> >
> >   qga-win: changing --retry-path option behavior (2018-10-30 09:06:28 -0500)
> >
> > ----------------------------------------------------------------
> > qemu-ga patch queue for soft-freeze
> >
> > * support for --retry-path option for recovering from communication
> >   path failures
> > * support for serial/device name in guest-get-fsinfo for linux/w32
> > * support for freezing individual mount points in guest-fsfreeze-*
> > * fixes for unicode paths on w32, not-present vcpus in guest-get-vcpus,
> >   buffer overflow in guest-get-fsinfo for w32, and other minor fixes
> >
> > ----------------------------------------------------------------
> 
> I get a compile failure here for my Ubuntu x86-64 host
> static build:
> 
>   LINK    qemu-ga
> /usr/bin/ld: cannot find -ludev
> 
> This is probably because my system has libudev as a dynamic
> library but not a static one. Googling suggests that libudev
> upstream don't support providing a static library, so we
> need to either make configure handle this case or declare
> (and enforce?) that --static requires --disable-tools.
> 
> It seems to me that a statically linked guest agent might
> be useful for some use cases? It would mean you didn't have
> to depend on the exact libraries the guest had installed.

Hi Peter,

Sorry for the breakage. Static is indeed useful for qemu-ga, but libudev
isn't a hard dependency for qemu-ga so we can get away with simply
disabling libudev for static builds. Would the following (squashed into
patch 04/24) be acceptable? This fixes static qemu-ga builds for me for
both Ubuntu 18.04 and FC27. I'll go ahead submit a v2 shortly since it
may be late for you:

--- a/configure
+++ b/configure
@@ -5608,7 +5608,7 @@ fi
 ##########################################
 # Do we have libudev
 if test "$libudev" != "no" ; then
-  if $pkg_config libudev; then
+  if $pkg_config libudev && test "$static" != "yes"; then
     if test "$static" != "yes"; then
       libudev="yes"
       libudev_libs=$($pkg_config --libs libudev)

> 
> (As an aside, it's an ubuntu bug that
> "pkg-config --static --libs libudev" doesn't correctly report
> that it can't do static linking of this library, but this
> is an extremely common bug in library pkg-config files.)
> 
> thanks
> -- PMM
>