Re: [PATCH 2/2] vbox: Fix starting domains

On 1/23/23 10:45, Martin Kletzander wrote: > On Mon, Jan 23, 2023 at 10:31:53AM +0100, Michal Privoznik wrote: >> When starting a VirtualBox domain, we try to guess which frontend >> to use. While the whole algorithm looks a bit outdated, it may >> happen that we tell VirtualBox to use "gui" frontend, but not >> which DISPLAY= to use. >> >> I haven't found any documentation on the algorithm we use, but if >> I make us fallback onto DISPLAY=:0 when no other configuration is >> found then I'm able to start my guests just fine. >> >> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; >> --- >> src/vbox/vbox_common.c | 13 ++++++------- >> 1 file changed, 6 insertions(+), 7 deletions(-) >> >> diff --git a/src/vbox/vbox_common.c b/src/vbox/vbox_common.c >> index bd77641d39..5269f9b23f 100644 >> --- a/src/vbox/vbox_common.c >> +++ b/src/vbox/vbox_common.c >> @@ -2121,13 +2121,12 @@ vboxStartMachine(virDomainPtr dom, int >> maxDomID, IMachine *machine, vboxIID *iid >>     VBOX_UTF8_FREE(valueDisplayUtf8); >> >>     if (guiPresent) { >> -        if (guiDisplay) { >> -            char *displayutf8; >> -            displayutf8 = g_strdup_printf("DISPLAY=%s", guiDisplay); >> -            VBOX_UTF8_TO_UTF16(displayutf8, &env); >> -            VIR_FREE(displayutf8); >> -            VIR_FREE(guiDisplay); >> -        } >> +        char *displayutf8; >> + >> +        displayutf8 = g_strdup_printf("DISPLAY=%s", guiDisplay ? >> guiDisplay : ":0"); >> +        VBOX_UTF8_TO_UTF16(displayutf8, &env); > > This might get overwritten when using SDL couple lines below.  I suggest > you default to :0 only if none other option remains.  It feels dirty > just guessing the display number, but let's say that's something we'll > have to live with in the vbox driver. I'm failing to see how guiPresent and sdlPresent can be set at the same time. But I guess I can join those two cases together, sure.

Michal