[patch added to the 3.12 stable tree] xen/console: Update console event channel on resume

Jiri Slaby
2015-05-15T14:28:31Z

From: Boris Ostrovsky <boris.ostrovsky@oracle.com>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.

===============

commit b9d934f27c91b878c4b2e64299d6e419a4022f8d upstream.

After a resume the hypervisor/tools may change console event
channel number. We should re-query it.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/tty/hvc/hvc_xen.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index c193af6a628f..b4805adc50af 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -299,11 +299,27 @@ static int xen_initial_domain_console_init(void)
return 0;
}

+static void xen_console_update_evtchn(struct xencons_info *info)
+{
+ if (xen_hvm_domain()) {
+ uint64_t v;
+ int err;
+
+ err = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
+ if (!err && v)
+ info->evtchn = v;
+ } else
+ info->evtchn = xen_start_info->console.domU.evtchn;
+}
+
void xen_console_resume(void)
{
struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE);
- if (info != NULL && info->irq)
+ if (info != NULL && info->irq) {
+ if (!xen_initial_domain())
+ xen_console_update_evtchn(info);
rebind_evtchn_irq(info->evtchn, info->irq);
+ }
}

static void xencons_disconnect_backend(struct xencons_info *info)
--
2.3.7