[Xen-devel] [PATCH 2/4] xen: do not initialize the interval timer emulator

[<stefano.stabellini@xxxxxxxxxxxxx>]

From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>

PIT is emulated by the hypervisor so we don't need to emulate it in Qemu:
this patch prevents Qemu from waking up needlessly at PIT_FREQ on Xen.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
 hw/pc.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/hw/pc.c b/hw/pc.c
index 33778fe..a0ae981 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -43,6 +43,7 @@
 #include "ui/qemu-spice.h"
 #include "memory.h"
 #include "exec-memory.h"
+#include "arch_init.h"
 
 /* output Bochs bios info messages */
 //#define DEBUG_BIOS
@@ -1121,7 +1122,7 @@ void pc_basic_device_init(qemu_irq *gsi,
     DriveInfo *fd[MAX_FD];
     qemu_irq rtc_irq = NULL;
     qemu_irq *a20_line;
-    ISADevice *i8042, *port92, *vmmouse, *pit;
+    ISADevice *i8042, *port92, *vmmouse, *pit = NULL;
     qemu_irq *cpu_exit_irq;
 
     register_ioport_write(0x80, 1, 1, ioport80_write, NULL);
@@ -1142,7 +1143,9 @@ void pc_basic_device_init(qemu_irq *gsi,
 
     qemu_register_boot_set(pc_boot_set, *rtc_state);
 
-    pit = pit_init(0x40, 0);
+    if (!xen_available()) {
+        pit = pit_init(0x40, 0);
+    }
     pcspk_init(pit);
 
     for(i = 0; i < MAX_SERIAL_PORTS; i++) {
-- 
1.7.2.3


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