From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: ia64: why is mmio bus access lockless?
Date: Wed, 24 Jun 2009 18:00:43 +0300
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Hi,
arch/ia64/kvm/kvm-ia64.c does this:

       mmio_dev = vcpu_find_mmio_dev(vcpu, p->addr, p->size, !p->dir);
       if (mmio_dev) {
               if (!p->dir)
                       kvm_iodevice_write(mmio_dev, p->addr, p->size,
                                               &p->data);
               else
                       kvm_iodevice_read(mmio_dev, p->addr, p->size,
                                               &p->data);
without holding kvm lock.

I know that find/read/write on the bus require locking on x86 -
are they safe to do without locking on ia64?

-- 
MST