From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arun Sharma <arun.sharma@intel.com>
Subject: [PATCH] vmx-pit-reset.patch
Date: Wed, 25 May 2005 11:27:33 -0700
Message-ID: <20050525182733.GA497@intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <xen-devel-bounces@lists.xensource.com>
Content-Disposition: inline
List-Unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: Ian Pratt <Ian.Pratt@cl.cam.ac.uk>, Keir Fraser <Keir.Fraser@cl.cam.ac.uk>
Cc: xen-devel@lists.xensource.com
List-Id: xen-devel@lists.xenproject.org

A VMX guest can reprogram the same PIT channel twice. We should not create
two ac_timers to handle this case.

Signed-off-by: Edwin Zhai <edwin.zhai@intel.com>
Signed-off-by: Arun Sharma <arun.sharma@intel.com>

--- trunk/xen/arch/x86/vmx_intercept.c	(revision 1122)
+++ trunk/xen/arch/x86/vmx_intercept.c	(working copy)
@@ -217,6 +217,14 @@ void vmx_hooks_assist(struct exec_domain
 
     /* load init count*/
     if (p->state == STATE_IORESP_HOOK) { 
+        /* set up actimer, handle re-init */
+        if ( active_ac_timer(&(vpit->pit_timer)) ) {
+            VMX_DBG_LOG(DBG_LEVEL_1, "VMX_PIT: guest reset PIT with channel %lx!\n", (unsigned long) ((p->u.data >> 24) & 0x3) );
+            rem_ac_timer(&(vpit->pit_timer));
+        }
+        else
+            init_ac_timer(&(vpit->pit_timer));
+
         /* init count for this channel */
         vpit->init_val = (p->u.data & 0xFFFF) ; 
         /* frequency(ms) of pit */
@@ -251,12 +259,11 @@ void vmx_hooks_assist(struct exec_domain
 
         vpit->intr_bitmap = intr;
 
-        /* set up the actimer */
-        init_ac_timer(&(vpit->pit_timer));
         vpit->pit_timer.cpu = 0; /*FIXME: change for SMP */
         vpit->pit_timer.data = (unsigned long)vpit;
         vpit->pit_timer.function = pit_timer_fn;
-        pit_timer_fn((unsigned long)vpit); /* timer seed */
+
+        add_ac_timer(&(vpit->pit_timer));
 
         /*restore the state*/
         p->state = STATE_IORESP_READY;