[Xen-changelog] [xen-unstable] arm/vtimer: do not let the guest interact with the physical timer

[Xen patchbot-unstable <patchbot@xxxxxxx>]

# HG changeset patch
# User Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
# Date 1342542124 -3600
# Node ID d53381ebdb3287d002e1179f6774516e70399490
# Parent  9950f2dc2ee6dfd172258a5a4ee29809b0ff8263
arm/vtimer: do not let the guest interact with the physical timer

The guest can read the physical counter but it shouldn't be able to
cause interrupts of the physical timer to go to the hypervisor.
Trap physical timer reads/writes in vtimer.c instead.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Acked-by: Tim Deegan <tim@xxxxxxx>
Committed-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---


diff -r 9950f2dc2ee6 -r d53381ebdb32 xen/arch/arm/time.c
--- a/xen/arch/arm/time.c       Mon Jul 09 10:10:27 2012 +0100
+++ b/xen/arch/arm/time.c       Tue Jul 17 17:22:04 2012 +0100
@@ -160,8 +160,8 @@ void __cpuinit init_timer_interrupt(void
     WRITE_CP64(0, CNTVOFF);     /* No VM-specific offset */
     WRITE_CP32(0, CNTKCTL);     /* No user-mode access */
 #if USE_HYP_TIMER
-    /* Let the VMs read the physical counter and timer so they can tell time */
-    WRITE_CP32(CNTHCTL_PA|CNTHCTL_TA, CNTHCTL);
+    /* Do not let the VMs program the physical timer, only read the physical 
counter */
+    WRITE_CP32(CNTHCTL_PA, CNTHCTL);
 #else
     /* Cannot let VMs access physical counter if we are using it */
     WRITE_CP32(0, CNTHCTL);

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