On 1/10/20 11:34 AM, Daniel P. Berrangé wrote:
> The previous "QEMU shim" proof of concept was taking an approach of only
> caring about initial spawning of the QEMU process. It was then
> registered with the libvirtd daemon who took over management of it. The
> intent was that later libvirtd would be refactored so that the shim
> retained control over the QEMU monitor and libvirt just forwarded APIs
> to each shim as needed. This forwarding of APIs would require quite alot
> of significant refactoring of libvirtd to achieve.
>
> This impl thus takes a quite different approach, explicitly deciding to
> keep the VMs completely separate from those seen & managed by libvirtd.
> Instead it uses the new "qemu:///embed" URI scheme to embed the entire
> QEMU driver in the shim, running with a custom root directory.
>
> Once the driver is initialization, the shim starts a VM and then waits
> to shutdown automatically when QEMU shuts down, or should kill QEMU if
> it is terminated itself. This ought to use the AUTO_DESTROY feature but
> that is not yet available in embedded mode, so we rely on installing a
> few signal handlers to gracefully kill QEMU. This isn't reliable if
> we crash of course, but you can restart with the same root dir.
>
> Note this program does not expose any way to manage the QEMU process,
> since there's no RPC interface enabled. It merely starts the VM and
> cleans up when the guest shuts down at the end. This program is
> installed to /usr/bin/virt-qemu-run enabling direct use by end users.
> Most use cases will probably want to integrate the concept directly
> into their respective application codebases. This standalone binary
> serves as a nice demo though, and also provides a way to measure
> performance of the startup process quite simply.
>
> Reviewed-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
> Signed-off-by: Daniel P. Berrangé <berrange@xxxxxxxxxx>
> ---
> build-aux/syntax-check.mk | 2 +-
> docs/Makefile.am | 5 +
> docs/manpages/index.rst | 1 +
> docs/manpages/virt-qemu-run.rst | 114 +++++++++++
> libvirt.spec.in | 2 +
> src/Makefile.am | 1 +
> src/qemu/Makefile.inc.am | 13 ++
> src/qemu/qemu_shim.c | 322 ++++++++++++++++++++++++++++++++
> 8 files changed, 459 insertions(+), 1 deletion(-)
> create mode 100644 docs/manpages/virt-qemu-run.rst
> create mode 100644 src/qemu/qemu_shim.c
>
> --- /dev/null
> +++ b/src/qemu/qemu_shim.c
> +int main(int argc, char **argv)
> +{
> + GThread *eventLoopThread = NULL;
> + virConnectPtr conn = NULL;
> + virConnectPtr sconn = NULL;
> + g_autofree char *xml = NULL;
> + g_autofree char *uri = NULL;
> + g_autofree char *suri = NULL;
> + char *root = NULL;
> + bool tmproot = false;
> + int ret = 1;
> + g_autoptr(GError) error = NULL;
> + g_auto(GStrv) secrets = NULL;
> + gboolean verbose = false;
> + gboolean debug = false;
> + GStrv tmpsecrets;
> + GOptionContext *ctx;
> + GOptionEntry entries[] = {
> + { "secret", 's', 0, G_OPTION_ARG_STRING_ARRAY, &secrets, "Load secret file", "SECRET-XML-FILE,SECRET-VALUE-FILE" },
> + { "root", 'r', 0, G_OPTION_ARG_STRING, &root, "Root directory", "DIR"},
> + { "debug", 'd', 0, G_OPTION_ARG_NONE, &debug, "Debug output", NULL },
> + { "verbose", 'v', 0, G_OPTION_ARG_NONE, &verbose, "Verbose output", NULL },
> + { NULL }
s/NULL/0/ to make clang happy. It's complaining, that the rest of struct
members are not initialzied.
Michal
