Re: [PATCH 01/18] Make TSC offset writes non-preemptible

From: Avi Kivity
Date: Sun Jul 18 2010 - 10:30:48 EST


On 07/13/2010 05:25 AM, Zachary Amsden wrote:

+void guest_write_tsc(struct kvm_vcpu *vcpu, u64 data)
+{
+ struct kvm *kvm = vcpu->kvm;
+ u64 offset;
+
+ spin_lock(&kvm->arch.tsc_write_lock);

Perhaps spin_lock_irq() for even more accuracy?

spin_lock_irq_nmi_smi_hypervisor(), if you can find it.

+ offset = data - native_read_tsc();
+ kvm_x86_ops->write_tsc_offset(vcpu, offset);
+ spin_unlock(&kvm->arch.tsc_write_lock);
+
+ /* Reset of TSC must disable overshoot protection below */
+ vcpu->arch.hv_clock.tsc_timestamp = 0;
+}
+EXPORT_SYMBOL_GPL(guest_write_tsc);
+


--
error compiling committee.c: too many arguments to function

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/