Attachment 147352 Details for Bug 193292 – Patch to disable the PV timer

[patch] Patch to disable the PV timer

0001-xen-add-tunnable-to-disable-PV-timer.patch (text/plain), 1.21 KB, created by Roger Pau Monné on 2014-09-15 16:28:00 UTC

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Creator: Roger Pau Monné

Created: 2014-09-15 16:28:00 UTC

Size: 1.21 KB

patch

obsolete

>From ed2814e1e3780b32bb34965e41045e75115714bb Mon Sep 17 00:00:00 2001
>From: Roger Pau Monne <roger.pau@citrix.com>
>Date: Mon, 15 Sep 2014 18:24:14 +0200
>Subject: [PATCH] xen: add tunnable to disable PV timer
>
>The Xen PV eventtimer/timecounter/clock had some bugs when used with PVHVM
>guests. Since there are Xen versions in the wild that don't have the
>necessary fixes to make the PV timer usable, allow the user to disable it at
>boot time.
>
>Sponsored by: Citrix Systems R&D
>---
> sys/dev/xen/timer/timer.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
>diff --git a/sys/dev/xen/timer/timer.c b/sys/dev/xen/timer/timer.c
>index 5743076..1ee1e58 100644
>--- a/sys/dev/xen/timer/timer.c
>+++ b/sys/dev/xen/timer/timer.c
>@@ -95,13 +95,16 @@ struct xentimer_softc {
> 	struct eventtimer et;
> };
> 
>+int xentimer_disable = 0;
>+TUNABLE_INT("hw.xen.disable_pv_timer", &xentimer_disable);
>+
> /* Last time; this guarantees a monotonically increasing clock. */
> volatile uint64_t xen_timer_last_time = 0;
> 
> static void
> xentimer_identify(driver_t *driver, device_t parent)
> {
>-	if (!xen_domain())
>+	if (!xen_domain() || (xentimer_disable != 0))
> 		return;
> 
> 	/* Handle all Xen PV timers in one device instance. */
>-- 
>1.8.5.2 (Apple Git-48)
>

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Attachments on bug 193292: 147352