x86: split struct domain

This is accomplished by converting a couple of embedded arrays (in one
case a structure containing an array) into separately allocated
pointers, and (just as for struct arch_vcpu in a prior patch)
overlaying some PV-only fields with HVM-only ones.

One particularly noteworthy change in the opposite direction is that
of PITState - this field so far lived in the HVM-only portion, but is
being used by PV guests too, and hence needed to be moved out of
struct hvm_domain.

The change to XENMEM_set_memory_map (and hence libxl__build_pre() and
the movement of the E820 related pieces to struct pv_domain) are
subject to a positive response to a query sent to xen-devel regarding
the need for this to happen for HVM guests (see
http://lists.xensource.com/archives/html/xen-devel/2011-03/msg01848.html).

The protection of arch.hvm_domain.irq.dpci accesses by is_hvm_domain()
is subject to confirmation that the field is used for HVM guests only
(see
http://lists.xensource.com/archives/html/xen-devel/2011-03/msg02004.html).

In the absence of any reply to these queries, and given the early
state of 4.2 development, I think it should be acceptable to take the
risk of having to later undo/redo some of this.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/xen/arch/x86/physdev.c b/xen/arch/x86/physdev.c
index 8fdd4df37d..e15dd0a95d 100644
--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -264,7 +264,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
         ret = -EINVAL;
         if ( eoi.irq >= v->domain->nr_pirqs )
             break;
-        if ( v->domain->arch.pirq_eoi_map )
+        if ( !is_hvm_domain(v->domain) &&
+             v->domain->arch.pv_domain.pirq_eoi_map )
             evtchn_unmask(v->domain->pirq_to_evtchn[eoi.irq]);
         if ( !is_hvm_domain(v->domain) ||
              domain_pirq_to_emuirq(v->domain, eoi.irq) == IRQ_PT )
@@ -289,17 +290,18 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
                                 PGT_writable_page) )
             break;
 
-        if ( cmpxchg(&v->domain->arch.pirq_eoi_map_mfn, 0, mfn) != 0 )
+        if ( cmpxchg(&v->domain->arch.pv_domain.pirq_eoi_map_mfn,
+                     0, mfn) != 0 )
         {
             put_page_and_type(mfn_to_page(mfn));
             ret = -EBUSY;
             break;
         }
 
-        v->domain->arch.pirq_eoi_map = map_domain_page_global(mfn);
-        if ( v->domain->arch.pirq_eoi_map == NULL )
+        v->domain->arch.pv_domain.pirq_eoi_map = map_domain_page_global(mfn);
+        if ( v->domain->arch.pv_domain.pirq_eoi_map == NULL )
         {
-            v->domain->arch.pirq_eoi_map_mfn = 0;
+            v->domain->arch.pv_domain.pirq_eoi_map_mfn = 0;
             put_page_and_type(mfn_to_page(mfn));
             ret = -ENOSPC;
             break;