| Message ID | 20200428040433.23504-15-jandryuk@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add support for qemu-xen runnning in a Linux-based stubdomain | expand |
Jason Andryuk writes ("[PATCH v5 14/21] libxl: require qemu in dom0 even if stubdomain is in use"):
> From: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
>
> Until xenconsoled learns how to handle multiple consoles, this is needed
> for save/restore support (qemu state is transferred over secondary
> consoles).
> Additionally, Linux-based stubdomain waits for all the backends to
> initialize during boot. Lack of some console backends results in
> stubdomain startup timeout.
>
> This is a temporary patch until xenconsoled will be improved.
>
> Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
> Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
> ---
> tools/libxl/libxl_dm.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
> index e420c3fc7b..5e5e7a27b3 100644
> --- a/tools/libxl/libxl_dm.c
> +++ b/tools/libxl/libxl_dm.c
> @@ -2484,7 +2484,11 @@ static void spawn_stub_launch_dm(libxl__egc *egc,
> }
> }
>
> - need_qemu = libxl__need_xenpv_qemu(gc, dm_config);
> + /*
> + * Until xenconsoled learns how to handle multiple consoles, require qemu
> + * in dom0 to serve consoles for a stubdomain - it require at least 3 of them.
> + */
> + need_qemu = 1 || libxl__need_xenpv_qemu(gc, &sdss->dm_config);
But I don't think this is true for a trad non-linux stubdm ?
So I think this ought to be conditional.
What am I missing ?
Regards,
Ian.
On Thu, May 14, 2020 at 05:42:36PM +0100, Ian Jackson wrote: > Jason Andryuk writes ("[PATCH v5 14/21] libxl: require qemu in dom0 even if stubdomain is in use"): > > From: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > > > > Until xenconsoled learns how to handle multiple consoles, this is needed > > for save/restore support (qemu state is transferred over secondary > > consoles). > > Additionally, Linux-based stubdomain waits for all the backends to > > initialize during boot. Lack of some console backends results in > > stubdomain startup timeout. > > > > This is a temporary patch until xenconsoled will be improved. > > > > Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > > Signed-off-by: Jason Andryuk <jandryuk@gmail.com> > > --- > > tools/libxl/libxl_dm.c | 12 ++++++++++-- > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c > > index e420c3fc7b..5e5e7a27b3 100644 > > --- a/tools/libxl/libxl_dm.c > > +++ b/tools/libxl/libxl_dm.c > > @@ -2484,7 +2484,11 @@ static void spawn_stub_launch_dm(libxl__egc *egc, > > } > > } > > > > - need_qemu = libxl__need_xenpv_qemu(gc, dm_config); > > + /* > > + * Until xenconsoled learns how to handle multiple consoles, require qemu > > + * in dom0 to serve consoles for a stubdomain - it require at least 3 of them. > > + */ > > + need_qemu = 1 || libxl__need_xenpv_qemu(gc, &sdss->dm_config); > > But I don't think this is true for a trad non-linux stubdm ? > So I think this ought to be conditional. For qemu-trad is true too. Stubdomain (mini-os + qemu-trad and linux + qemu-xen) is always started with at least 3 consoles: log, save, restore. Which currently requires qemu in dom0. So, yes, technically it is a bug in the current libxl for qemu-trad. In practice, it works in most cases because there is something else that triggers qemu in dom0 too: vfb/vkb added if vnc/sdl/spice is enabled.
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c index e420c3fc7b..5e5e7a27b3 100644 --- a/tools/libxl/libxl_dm.c +++ b/tools/libxl/libxl_dm.c @@ -2484,7 +2484,11 @@ static void spawn_stub_launch_dm(libxl__egc *egc, } } - need_qemu = libxl__need_xenpv_qemu(gc, dm_config); + /* + * Until xenconsoled learns how to handle multiple consoles, require qemu + * in dom0 to serve consoles for a stubdomain - it require at least 3 of them. + */ + need_qemu = 1 || libxl__need_xenpv_qemu(gc, &sdss->dm_config); for (i = 0; i < num_console; i++) { libxl__device device; @@ -2616,7 +2620,11 @@ static void qmp_proxy_spawn_outcome(libxl__egc *egc, int rc) { STATE_AO_GC(sdss->qmp_proxy_spawn.ao); - int need_pvqemu = libxl__need_xenpv_qemu(gc, &sdss->dm_config); + /* + * Until xenconsoled learns how to handle multiple consoles, require qemu + * in dom0 to serve consoles for a stubdomain - it require at least 3 of them. + */ + int need_pvqemu = 1 || libxl__need_xenpv_qemu(gc, &sdss->dm_config); if (rc) goto out;