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authorBharat Bhushan <r65777@freescale.com>2011-10-19 09:46:06 +0530
committerAvi Kivity <avi@redhat.com>2012-03-05 14:52:25 +0200
commitdc2babfea592e633cf3890294af6545609b466be (patch)
tree7c125d33df2a5de4b433b4a7c635fa13096f4d90 /arch/powerpc/kvm/emulate.c
parentf9208427f72e6cb52c71767af3bf8c14c43c27ac (diff)
downloadlinux-dc2babfea592e633cf3890294af6545609b466be.tar.bz2
KVM: PPC: Fix DEC truncation for greater than 0xffff_ffff/1000
kvmppc_emulate_dec() uses dec_nsec of type unsigned long and does below calculation: dec_nsec = vcpu->arch.dec; dec_nsec *= 1000; This will truncate if DEC value "vcpu->arch.dec" is greater than 0xffff_ffff/1000. For example : For tb_ticks_per_usec = 4a, we can not set decrementer more than ~58ms. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Acked-by: Liu Yu <yu.liu@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/powerpc/kvm/emulate.c')
-rw-r--r--arch/powerpc/kvm/emulate.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index 141dce3c6810..4337f99fa0fa 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -84,6 +84,7 @@ static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
{
unsigned long dec_nsec;
+ unsigned long long dec_time;
pr_debug("mtDEC: %x\n", vcpu->arch.dec);
#ifdef CONFIG_PPC_BOOK3S
@@ -103,11 +104,12 @@ void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
* host ticks. */
hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
- dec_nsec = vcpu->arch.dec;
- dec_nsec *= 1000;
- dec_nsec /= tb_ticks_per_usec;
- hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
- HRTIMER_MODE_REL);
+ dec_time = vcpu->arch.dec;
+ dec_time *= 1000;
+ do_div(dec_time, tb_ticks_per_usec);
+ dec_nsec = do_div(dec_time, NSEC_PER_SEC);
+ hrtimer_start(&vcpu->arch.dec_timer,
+ ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
vcpu->arch.dec_jiffies = get_tb();
} else {
hrtimer_try_to_cancel(&vcpu->arch.dec_timer);