[PATCH v5 02/12] hw/mips/cputimer: Don't start periodic timer in KVM mode

James Hogan
2014-06-17T22:14:11Z

From: Sanjay Lal <sanjayl@kymasys.com>

Compare/Count timer interrupts are handled in-kernel for KVM. Therefore
don't bother creating the timer at init time if KVM is enabled. This
will conveniently avoid attempts to set the timeout when
cpu_mips_store_count() is called at reset with KVM enabled, treating the
timer as stopped so that CP0_Count is modified directly.

Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
[james.hogan@imgtec.com: Update after "target-mips: Reset CPU timer
consistently" which moves timer start to reset time]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
---
Changes in v5:
- Update commit message and comment in cpu_mips_clock_init() after the
patch "target-mips: Reset CPU timer consistently") (Paolo Bonzini).

Changes in v2:
- Expand commit message
- Rebase on v1.7.0
- Wrap comment
---
hw/mips/cputimer.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/hw/mips/cputimer.c b/hw/mips/cputimer.c
index 6900a745c60c..577c9aeab877 100644
--- a/hw/mips/cputimer.c
+++ b/hw/mips/cputimer.c
@@ -23,6 +23,7 @@
#include "hw/hw.h"
#include "hw/mips/cpudevs.h"
#include "qemu/timer.h"
+#include "sysemu/kvm.h"

#define TIMER_FREQ 100 * 1000 * 1000

@@ -146,5 +147,11 @@ static void mips_timer_cb (void *opaque)

void cpu_mips_clock_init (CPUMIPSState *env)
{
- env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &mips_timer_cb, env);
+ /*
+ * If we're in KVM mode, don't create the periodic timer, that is handled in
+ * kernel.
+ */
+ if (!kvm_enabled()) {
+ env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &mips_timer_cb, env);
+ }
}
--
1.9.3