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| author | Bharat Bhushan <r65777@freescale.com> | 2011-10-19 04:16:06 (GMT) |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-03-05 12:52:25 (GMT) |
| commit | dc2babfea592e633cf3890294af6545609b466be (patch) | |
| tree | 7c125d33df2a5de4b433b4a7c635fa13096f4d90 /arch/powerpc/kvm | |
| parent | f9208427f72e6cb52c71767af3bf8c14c43c27ac (diff) | |
| download | linux-dc2babfea592e633cf3890294af6545609b466be.tar.xz | |
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')
| -rw-r--r-- | arch/powerpc/kvm/emulate.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c index 141dce3..4337f99 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); |