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Date: Fri, 15 May 2020 13:26:16 -0400 From: Boris Ostrovsky <boris.ostrovsky@...cle.com> To: Jürgen Groß <jgross@...e.com>, Dongli Zhang <dongli.zhang@...cle.com>, xen-devel@...ts.xenproject.org, linux-kernel@...r.kernel.org Cc: sstabellini@...nel.org, joe.jin@...cle.com, rose.wang@...cle.com Subject: Re: [PATCH 1/1] xen/manage: enable C_A_D to force reboot On 5/15/20 3:01 AM, Jürgen Groß wrote: > On 14.05.20 01:34, Dongli Zhang wrote: >> The systemd may be configured to mask ctrl-alt-del via "systemctl mask >> ctrl-alt-del.target". As a result, the pv reboot would not work as >> signal >> is ignored. >> >> This patch always enables C_A_D before the call of ctrl_alt_del() in >> order >> to force the reboot. > > Hmm, I'm not sure this is a good idea. > > Suppose a guest admin is doing a critical update and wants to avoid a > sudden reboot in between. By masking the reboot this would be possible, > with your patch it isn't. > > In case a reboot is really mandatory it would still be possible to just > kill the guest. > > I'm not completely opposed to the patch, but I think this is a change > which should not be done easily. I think 'xl reboot -F' should do be handling this scenario but (1) it is currently not quite set up for this and (2) I can't see how it works at all given that noone handles LIBXL_TRIGGER_RESET in arch_do_domctl(XEN_DOMCTL_sendtrigger). -boris > > > Juergen > >> >> Reported-by: Rose Wang <rose.wang@...cle.com> >> Cc: Joe Jin <joe.jin@...cle.com> >> Cc: Boris Ostrovsky <boris.ostrovsky@...cle.com> >> Signed-off-by: Dongli Zhang <dongli.zhang@...cle.com> >> --- >> drivers/xen/manage.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c >> index cd046684e0d1..3190d0ecb52e 100644 >> --- a/drivers/xen/manage.c >> +++ b/drivers/xen/manage.c >> @@ -204,6 +204,13 @@ static void do_poweroff(void) >> static void do_reboot(void) >> { >> shutting_down = SHUTDOWN_POWEROFF; /* ? */ >> + /* >> + * The systemd may be configured to mask ctrl-alt-del via >> + * "systemctl mask ctrl-alt-del.target". As a result, the pv reboot >> + * would not work. To enable C_A_D would force the reboot. >> + */ >> + C_A_D = 1; >> + >> ctrl_alt_del(); >> } >> >
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