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@xxxxxxxxxx>

--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -72,9 +72,9 @@ int libxl__build_pre(libxl__gc *gc, uint
     libxl_ctx *ctx = libxl__gc_owner(gc);
     xc_domain_max_vcpus(ctx->xch, domid, info->max_vcpus);
     xc_domain_setmaxmem(ctx->xch, domid, info->target_memkb + LIBXL_MAXMEM_CONSTANT);
-    xc_domain_set_memmap_limit(ctx->xch, domid, 
-            (info->hvm) ? info->max_memkb : 
-            (info->max_memkb + info->u.pv.slack_memkb));
+    if (!info->hvm)
+        xc_domain_set_memmap_limit(ctx->xch, domid,
+                (info->max_memkb + info->u.pv.slack_memkb));
     xc_domain_set_tsc_info(ctx->xch, domid, info->tsc_mode, 0, 0, 0);
     if ( info->disable_migrate )
         xc_domain_disable_migrate(ctx->xch, domid);
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -187,16 +187,17 @@ struct domain *alloc_domain_struct(void)
 #ifdef __x86_64__
     bits += pfn_pdx_hole_shift;
 #endif
-    d = alloc_xenheap_pages(get_order_from_bytes(sizeof(*d)), MEMF_bits(bits));
+    BUILD_BUG_ON(sizeof(*d) > PAGE_SIZE);
+    d = alloc_xenheap_pages(0, MEMF_bits(bits));
     if ( d != NULL )
-        memset(d, 0, sizeof(*d));
+        clear_page(d);
     return d;
 }
 
 void free_domain_struct(struct domain *d)
 {
     lock_profile_deregister_struct(LOCKPROF_TYPE_PERDOM, d);
-    free_xenheap_pages(d, get_order_from_bytes(sizeof(*d)));
+    free_xenheap_page(d);
 }
 
 struct vcpu *alloc_vcpu_struct(void)
@@ -531,6 +532,17 @@ int arch_domain_create(struct domain *d,
 
     if ( !is_idle_domain(d) )
     {
+        d->arch.cpuids = xmalloc_array(cpuid_input_t, MAX_CPUID_INPUT);
+        rc = -ENOMEM;
+        if ( d->arch.cpuids == NULL )
+            goto fail;
+        memset(d->arch.cpuids, 0, MAX_CPUID_INPUT * sizeof(*d->arch.cpuids));
+        for ( i = 0; i < MAX_CPUID_INPUT; i++ )
+        {
+            d->arch.cpuids[i].input[0] = XEN_CPUID_INPUT_UNUSED;
+            d->arch.cpuids[i].input[1] = XEN_CPUID_INPUT_UNUSED;
+        }
+
         d->arch.ioport_caps = 
             rangeset_new(d, "I/O Ports", RANGESETF_prettyprint_hex);
         rc = -ENOMEM;
@@ -599,13 +611,6 @@ int arch_domain_create(struct domain *d,
             (CONFIG_PAGING_LEVELS != 4);
     }
 
-    memset(d->arch.cpuids, 0, sizeof(d->arch.cpuids));
-    for ( i = 0; i < MAX_CPUID_INPUT; i++ )
-    {
-        d->arch.cpuids[i].input[0] = XEN_CPUID_INPUT_UNUSED;
-        d->arch.cpuids[i].input[1] = XEN_CPUID_INPUT_UNUSED;
-    }
-
     /* initialize default tsc behavior in case tools don't */
     tsc_set_info(d, TSC_MODE_DEFAULT, 0UL, 0, 0);
     spin_lock_init(&d->arch.vtsc_lock);
@@ -2067,11 +2072,12 @@ int domain_relinquish_resources(struct d
                 unmap_vcpu_info(v);
             }
 
-            if ( d->arch.pirq_eoi_map != NULL )
+            if ( d->arch.pv_domain.pirq_eoi_map != NULL )
             {
-                unmap_domain_page_global(d->arch.pirq_eoi_map);
-                put_page_and_type(mfn_to_page(d->arch.pirq_eoi_map_mfn));
-                d->arch.pirq_eoi_map = NULL;
+                unmap_domain_page_global(d->arch.pv_domain.pirq_eoi_map);
+                put_page_and_type(
+                    mfn_to_page(d->arch.pv_domain.pirq_eoi_map_mfn));
+                d->arch.pv_domain.pirq_eoi_map = NULL;
             }
         }
 
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -900,6 +900,10 @@ long arch_do_domctl(
             break;
         bind = &(domctl->u.bind_pt_irq);
 
+        ret = -EINVAL;
+        if ( !is_hvm_domain(d) )
+            goto bind_out;
+
         ret = xsm_bind_pt_irq(d, bind);
         if ( ret )
             goto bind_out;
--- a/xen/arch/x86/hvm/hpet.c
+++ b/xen/arch/x86/hvm/hpet.c
@@ -237,8 +237,7 @@ static void hpet_set_timer(HPETState *h,
     {
         /* HPET specification requires PIT shouldn't generate
          * interrupts if LegacyReplacementRoute is set for timer0 */
-        PITState *pit = &vhpet_domain(h)->arch.hvm_domain.pl_time.vpit;
-        pit_stop_channel0_irq(pit);
+        pit_stop_channel0_irq(&vhpet_domain(h)->arch.vpit);
     }
 
     if ( !timer_enabled(h, tn) )
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -412,7 +412,7 @@ static int hvm_print_line(
 
     spin_lock(&hd->pbuf_lock);
     hd->pbuf[hd->pbuf_idx++] = c;
-    if ( (hd->pbuf_idx == (sizeof(hd->pbuf) - 2)) || (c == '\n') )
+    if ( (hd->pbuf_idx == (HVM_PBUF_SIZE - 2)) || (c == '\n') )
     {
         if ( c != '\n' )
             hd->pbuf[hd->pbuf_idx++] = '\n';
@@ -443,6 +443,19 @@ int hvm_domain_initialise(struct domain 
     INIT_LIST_HEAD(&d->arch.hvm_domain.msixtbl_list);
     spin_lock_init(&d->arch.hvm_domain.msixtbl_list_lock);
 
+    d->arch.hvm_domain.pbuf = xmalloc_array(char, HVM_PBUF_SIZE);
+    d->arch.hvm_domain.params = xmalloc_array(uint64_t, HVM_NR_PARAMS);
+    d->arch.hvm_domain.io_handler = xmalloc(struct hvm_io_handler);
+    rc = -ENOMEM;
+    if ( !d->arch.hvm_domain.pbuf || !d->arch.hvm_domain.params ||
+         !d->arch.hvm_domain.io_handler )
+        goto fail0;
+    memset(d->arch.hvm_domain.pbuf, 0,
+           HVM_PBUF_SIZE * sizeof(*d->arch.hvm_domain.pbuf));
+    memset(d->arch.hvm_domain.params, 0,
+           HVM_NR_PARAMS * sizeof(*d->arch.hvm_domain.params));
+    d->arch.hvm_domain.io_handler->num_slot = 0;
+
     hvm_init_guest_time(d);
 
     d->arch.hvm_domain.params[HVM_PARAM_HPET_ENABLED] = 1;
@@ -480,6 +493,10 @@ int hvm_domain_initialise(struct domain 
     vioapic_deinit(d);
  fail1:
     hvm_destroy_cacheattr_region_list(d);
+ fail0:
+    xfree(d->arch.hvm_domain.io_handler);
+    xfree(d->arch.hvm_domain.params);
+    xfree(d->arch.hvm_domain.pbuf);
     return rc;
 }
 
@@ -500,6 +517,10 @@ void hvm_domain_relinquish_resources(str
         pmtimer_deinit(d);
         hpet_deinit(d);
     }
+
+    xfree(d->arch.hvm_domain.io_handler);
+    xfree(d->arch.hvm_domain.params);
+    xfree(d->arch.hvm_domain.pbuf);
 }
 
 void hvm_domain_destroy(struct domain *d)
@@ -2533,10 +2554,20 @@ static long hvm_grant_table_op(
 
 static long hvm_memory_op(int cmd, XEN_GUEST_HANDLE(void) arg)
 {
-    long rc = do_memory_op(cmd, arg);
-    if ( (cmd & MEMOP_CMD_MASK) == XENMEM_decrease_reservation )
+    long rc;
+
+    switch ( cmd & MEMOP_CMD_MASK )
+    {
+    case XENMEM_memory_map:
+    case XENMEM_machine_memory_map:
+    case XENMEM_machphys_mapping:
+        return -ENOSYS;
+    case XENMEM_decrease_reservation:
+        rc = do_memory_op(cmd, arg);
         current->domain->arch.hvm_domain.qemu_mapcache_invalidate = 1;
-    return rc;
+        return rc;
+    }
+    return do_memory_op(cmd, arg);
 }
 
 static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
@@ -2613,10 +2644,20 @@ static long hvm_grant_table_op_compat32(
 
 static long hvm_memory_op_compat32(int cmd, XEN_GUEST_HANDLE(void) arg)
 {
-    long rc = compat_memory_op(cmd, arg);
-    if ( (cmd & MEMOP_CMD_MASK) == XENMEM_decrease_reservation )
+    int rc;
+
+    switch ( cmd & MEMOP_CMD_MASK )
+    {
+    case XENMEM_memory_map:
+    case XENMEM_machine_memory_map:
+    case XENMEM_machphys_mapping:
+        return -ENOSYS;
+    case XENMEM_decrease_reservation:
+        rc = compat_memory_op(cmd, arg);
         current->domain->arch.hvm_domain.qemu_mapcache_invalidate = 1;
-    return rc;
+        return rc;
+    }
+    return compat_memory_op(cmd, arg);
 }
 
 static long hvm_vcpu_op_compat32(
--- a/xen/arch/x86/hvm/i8254.c
+++ b/xen/arch/x86/hvm/i8254.c
@@ -38,10 +38,9 @@
 #include <asm/hvm/vpt.h>
 #include <asm/current.h>
 
-#define domain_vpit(x) (&(x)->arch.hvm_domain.pl_time.vpit)
+#define domain_vpit(x) (&(x)->arch.vpit)
 #define vcpu_vpit(x)   (domain_vpit((x)->domain))
-#define vpit_domain(x) (container_of((x), struct domain, \
-                                     arch.hvm_domain.pl_time.vpit))
+#define vpit_domain(x) (container_of((x), struct domain, arch.vpit))
 #define vpit_vcpu(x)   (pt_global_vcpu_target(vpit_domain(x)))
 
 #define RW_STATE_LSB 1
@@ -450,14 +449,18 @@ void pit_reset(struct domain *d)
 
 void pit_init(struct vcpu *v, unsigned long cpu_khz)
 {
-    PITState *pit = vcpu_vpit(v);
+    struct domain *d = v->domain;
+    PITState *pit = domain_vpit(d);
 
     spin_lock_init(&pit->lock);
 
-    register_portio_handler(v->domain, PIT_BASE, 4, handle_pit_io);
-    register_portio_handler(v->domain, 0x61, 1, handle_speaker_io);
+    if ( is_hvm_domain(d) )
+    {
+        register_portio_handler(d, PIT_BASE, 4, handle_pit_io);
+        register_portio_handler(d, 0x61, 1, handle_speaker_io);
+    }
 
-    pit_reset(v->domain);
+    pit_reset(d);
 }
 
 void pit_deinit(struct domain *d)
--- a/xen/arch/x86/hvm/intercept.c
+++ b/xen/arch/x86/hvm/intercept.c
@@ -195,8 +195,7 @@ static int process_portio_intercept(port
 int hvm_io_intercept(ioreq_t *p, int type)
 {
     struct vcpu *v = current;
-    struct hvm_io_handler *handler =
-        &v->domain->arch.hvm_domain.io_handler;
+    struct hvm_io_handler *handler = v->domain->arch.hvm_domain.io_handler;
     int i;
     unsigned long addr, size;
 
@@ -230,7 +229,7 @@ void register_io_handler(
     struct domain *d, unsigned long addr, unsigned long size,
     void *action, int type)
 {
-    struct hvm_io_handler *handler = &d->arch.hvm_domain.io_handler;
+    struct hvm_io_handler *handler = d->arch.hvm_domain.io_handler;
     int num = handler->num_slot;
 
     BUG_ON(num >= MAX_IO_HANDLER);
@@ -246,7 +245,7 @@ void relocate_io_handler(
     struct domain *d, unsigned long old_addr, unsigned long new_addr,
     unsigned long size, int type)
 {
-    struct hvm_io_handler *handler = &d->arch.hvm_domain.io_handler;
+    struct hvm_io_handler *handler = d->arch.hvm_domain.io_handler;
     int i;
 
     for ( i = 0; i < handler->num_slot; i++ )
--- a/xen/arch/x86/hvm/vioapic.c
+++ b/xen/arch/x86/hvm/vioapic.c
@@ -272,8 +272,7 @@ static void ioapic_inj_irq(
 
 static inline int pit_channel0_enabled(void)
 {
-    PITState *pit = &current->domain->arch.hvm_domain.pl_time.vpit;
-    return pt_active(&pit->pt0);
+    return pt_active(&current->domain->arch.vpit.pt0);
 }
 
 static void vioapic_deliver(struct hvm_hw_vioapic *vioapic, int irq)
--- a/xen/arch/x86/hvm/vpt.c
+++ b/xen/arch/x86/hvm/vpt.c
@@ -463,17 +463,20 @@ static void pt_adjust_vcpu(struct period
 
 void pt_adjust_global_vcpu_target(struct vcpu *v)
 {
+    struct PITState *vpit;
     struct pl_time *pl_time;
     int i;
 
     if ( v == NULL )
         return;
 
-    pl_time = &v->domain->arch.hvm_domain.pl_time;
+    vpit = &v->domain->arch.vpit;
+
+    spin_lock(&vpit->lock);
+    pt_adjust_vcpu(&vpit->pt0, v);
+    spin_unlock(&vpit->lock);
 
-    spin_lock(&pl_time->vpit.lock);
-    pt_adjust_vcpu(&pl_time->vpit.pt0, v);
-    spin_unlock(&pl_time->vpit.lock);
+    pl_time = &v->domain->arch.hvm_domain.pl_time;
 
     spin_lock(&pl_time->vrtc.lock);
     pt_adjust_vcpu(&pl_time->vrtc.pt, v);
@@ -507,7 +510,7 @@ void pt_may_unmask_irq(struct domain *d,
 
     if ( d )
     {
-        pt_resume(&d->arch.hvm_domain.pl_time.vpit.pt0);
+        pt_resume(&d->arch.vpit.pt0);
         pt_resume(&d->arch.hvm_domain.pl_time.vrtc.pt);
         for ( i = 0; i < HPET_TIMER_NUM; i++ )
             pt_resume(&d->arch.hvm_domain.pl_time.vhpet.pt[i]);
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -764,14 +764,14 @@ bool_t cpu_has_pending_apic_eoi(void)
 
 static inline void set_pirq_eoi(struct domain *d, unsigned int irq)
 {
-    if ( d->arch.pirq_eoi_map )
-        set_bit(irq, d->arch.pirq_eoi_map);
+    if ( !is_hvm_domain(d) && d->arch.pv_domain.pirq_eoi_map )
+        set_bit(irq, d->arch.pv_domain.pirq_eoi_map);
 }
 
 static inline void clear_pirq_eoi(struct domain *d, unsigned int irq)
 {
-    if ( d->arch.pirq_eoi_map )
-        clear_bit(irq, d->arch.pirq_eoi_map);
+    if ( !is_hvm_domain(d) && d->arch.pv_domain.pirq_eoi_map )
+        clear_bit(irq, d->arch.pv_domain.pirq_eoi_map);
 }
 
 static void _irq_guest_eoi(struct irq_desc *desc)
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4710,7 +4710,7 @@ long arch_memory_op(int op, XEN_GUEST_HA
         if ( copy_from_guest(&fmap, arg, 1) )
             return -EFAULT;
 
-        if ( fmap.map.nr_entries > ARRAY_SIZE(d->arch.e820) )
+        if ( fmap.map.nr_entries > ARRAY_SIZE(d->arch.pv_domain.e820) )
             return -EINVAL;
 
         rc = rcu_lock_target_domain_by_id(fmap.domid, &d);
@@ -4724,9 +4724,15 @@ long arch_memory_op(int op, XEN_GUEST_HA
             return rc;
         }
 
-        rc = copy_from_guest(d->arch.e820, fmap.map.buffer,
+        if ( is_hvm_domain(d) )
+        {
+            rcu_unlock_domain(d);
+            return -EPERM;
+        }
+
+        rc = copy_from_guest(d->arch.pv_domain.e820, fmap.map.buffer,
                              fmap.map.nr_entries) ? -EFAULT : 0;
-        d->arch.nr_e820 = fmap.map.nr_entries;
+        d->arch.pv_domain.nr_e820 = fmap.map.nr_entries;
 
         rcu_unlock_domain(d);
         return rc;
@@ -4738,14 +4744,15 @@ long arch_memory_op(int op, XEN_GUEST_HA
         struct domain *d = current->domain;
 
         /* Backwards compatibility. */
-        if ( d->arch.nr_e820 == 0 )
+        if ( d->arch.pv_domain.nr_e820 == 0 )
             return -ENOSYS;
 
         if ( copy_from_guest(&map, arg, 1) )
             return -EFAULT;
 
-        map.nr_entries = min(map.nr_entries, d->arch.nr_e820);
-        if ( copy_to_guest(map.buffer, d->arch.e820, map.nr_entries) ||
+        map.nr_entries = min(map.nr_entries, d->arch.pv_domain.nr_e820);
+        if ( copy_to_guest(map.buffer, d->arch.pv_domain.e820,
+                           map.nr_entries) ||
              copy_to_guest(arg, &map, 1) )
             return -EFAULT;
 
--- 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_H
         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_H
                                 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;
--- a/xen/drivers/passthrough/io.c
+++ b/xen/drivers/passthrough/io.c
@@ -85,6 +85,14 @@ static void pt_irq_time_out(void *data)
     }
 }
 
+struct hvm_irq_dpci *domain_get_irq_dpci(const struct domain *d)
+{
+    if ( !d || !is_hvm_domain(d) )
+        return NULL;
+
+    return d->arch.hvm_domain.irq.dpci;
+}
+
 void free_hvm_irq_dpci(struct hvm_irq_dpci *dpci)
 {
     xfree(dpci->mirq);
@@ -150,12 +158,7 @@ int pt_irq_create_bind_vtd(
         for ( int i = 0; i < NR_HVM_IRQS; i++ )
             INIT_LIST_HEAD(&hvm_irq_dpci->girq[i]);
 
-        if ( domain_set_irq_dpci(d, hvm_irq_dpci) == 0 )
-        {
-            spin_unlock(&d->event_lock);
-            free_hvm_irq_dpci(hvm_irq_dpci);
-            return -EINVAL;
-        }
+        d->arch.hvm_domain.irq.dpci = hvm_irq_dpci;
     }
 
     if ( pt_irq_bind->irq_type == PT_IRQ_TYPE_MSI )
@@ -392,8 +395,7 @@ int hvm_do_IRQ_dpci(struct domain *d, un
     struct hvm_irq_dpci *dpci = domain_get_irq_dpci(d);
 
     ASSERT(spin_is_locked(&irq_desc[domain_pirq_to_irq(d, mirq)].lock));
-    if ( !iommu_enabled || (d == dom0) || !dpci ||
-         !test_bit(mirq, dpci->mapping))
+    if ( !iommu_enabled || !dpci || !test_bit(mirq, dpci->mapping))
         return 0;
 
     set_bit(mirq, dpci->dirq_mask);
--- a/xen/drivers/passthrough/vtd/ia64/vtd.c
+++ b/xen/drivers/passthrough/vtd/ia64/vtd.c
@@ -70,23 +70,6 @@ void *__init map_to_nocache_virt(int nr_
   return (void *) ( maddr + __IA64_UNCACHED_OFFSET);
 }
 
-struct hvm_irq_dpci *domain_get_irq_dpci(struct domain *domain)
-{
-    if ( !domain )
-        return NULL;
-
-    return domain->arch.hvm_domain.irq.dpci;
-}
-
-int domain_set_irq_dpci(struct domain *domain, struct hvm_irq_dpci *dpci)
-{
-    if ( !domain || !dpci )
-        return 0;
-
-    domain->arch.hvm_domain.irq.dpci = dpci;
-    return 1;
-}
-
 void hvm_dpci_isairq_eoi(struct domain *d, unsigned int isairq)
 {
     /* dummy */
--- a/xen/drivers/passthrough/vtd/x86/vtd.c
+++ b/xen/drivers/passthrough/vtd/x86/vtd.c
@@ -68,23 +68,6 @@ void *__init map_to_nocache_virt(int nr_
     return (void *)fix_to_virt(FIX_IOMMU_REGS_BASE_0 + nr_iommus);
 }
 
-struct hvm_irq_dpci *domain_get_irq_dpci(struct domain *domain)
-{
-    if ( !domain )
-        return NULL;
-
-    return domain->arch.hvm_domain.irq.dpci;
-}
-
-int domain_set_irq_dpci(struct domain *domain, struct hvm_irq_dpci *dpci)
-{
-    if ( !domain || !dpci )
-        return 0;
-
-    domain->arch.hvm_domain.irq.dpci = dpci;
-    return 1;
-}
-
 void hvm_dpci_isairq_eoi(struct domain *d, unsigned int isairq)
 {
     struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -231,6 +231,17 @@ struct time_scale {
     u32 mul_frac;
 };
 
+struct pv_domain
+{
+    /* Shared page for notifying that explicit PIRQ EOI is required. */
+    unsigned long *pirq_eoi_map;
+    unsigned long pirq_eoi_map_mfn;
+
+    /* Pseudophysical e820 map (XENMEM_memory_map).  */
+    struct e820entry e820[3];
+    unsigned int nr_e820;
+};
+
 struct arch_domain
 {
 #ifdef CONFIG_X86_64
@@ -253,7 +264,11 @@ struct arch_domain
     uint32_t pci_cf8;
 
     struct list_head pdev_list;
-    struct hvm_domain hvm_domain;
+
+    union {
+        struct pv_domain pv_domain;
+        struct hvm_domain hvm_domain;
+    };
 
     struct paging_domain paging;
     struct p2m_domain *p2m;
@@ -265,14 +280,6 @@ struct arch_domain
     int *emuirq_pirq;
     int *pirq_emuirq;
 
-    /* Shared page for notifying that explicit PIRQ EOI is required. */
-    unsigned long *pirq_eoi_map;
-    unsigned long pirq_eoi_map_mfn;
-
-    /* Pseudophysical e820 map (XENMEM_memory_map).  */
-    struct e820entry e820[3];
-    unsigned int nr_e820;
-
     /* Maximum physical-address bitwidth supported by this guest. */
     unsigned int physaddr_bitsize;
 
@@ -294,7 +301,9 @@ struct arch_domain
     } relmem;
     struct page_list_head relmem_list;
 
-    cpuid_input_t cpuids[MAX_CPUID_INPUT];
+    cpuid_input_t *cpuids;
+
+    struct PITState vpit;
 
     /* For Guest vMCA handling */
     struct domain_mca_msrs *vmca_msrs;
--- a/xen/include/asm-x86/hvm/domain.h
+++ b/xen/include/asm-x86/hvm/domain.h
@@ -47,7 +47,7 @@ struct hvm_domain {
 
     struct pl_time         pl_time;
 
-    struct hvm_io_handler  io_handler;
+    struct hvm_io_handler *io_handler;
 
     /* Lock protects access to irq, vpic and vioapic. */
     spinlock_t             irq_lock;
@@ -60,11 +60,12 @@ struct hvm_domain {
     struct vcpu           *i8259_target;
 
     /* hvm_print_line() logging. */
-    char                   pbuf[80];
+#define HVM_PBUF_SIZE 80
+    char                  *pbuf;
     int                    pbuf_idx;
     spinlock_t             pbuf_lock;
 
-    uint64_t               params[HVM_NR_PARAMS];
+    uint64_t              *params;
 
     /* Memory ranges with pinned cache attributes. */
     struct list_head       pinned_cacheattr_ranges;
--- a/xen/include/asm-x86/hvm/vpt.h
+++ b/xen/include/asm-x86/hvm/vpt.h
@@ -124,7 +124,6 @@ typedef struct PMTState {
 } PMTState;
 
 struct pl_time {    /* platform time */
-    struct PITState  vpit;
     struct RTCState  vrtc;
     struct HPETState vhpet;
     struct PMTState  vpmt;
@@ -143,7 +142,9 @@ void pt_migrate(struct vcpu *v);
 
 void pt_adjust_global_vcpu_target(struct vcpu *v);
 #define pt_global_vcpu_target(d) \
-    ((d)->arch.hvm_domain.i8259_target ? : (d)->vcpu ? (d)->vcpu[0] : NULL)
+    (is_hvm_domain(d) && (d)->arch.hvm_domain.i8259_target ? \
+     (d)->arch.hvm_domain.i8259_target : \
+     (d)->vcpu ? (d)->vcpu[0] : NULL)
 
 void pt_may_unmask_irq(struct domain *d, struct periodic_time *vlapic_pt);
 
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -106,8 +106,7 @@ struct qi_ctrl *iommu_qi_ctrl(struct iom
 struct ir_ctrl *iommu_ir_ctrl(struct iommu *iommu);
 struct iommu_flush *iommu_get_flush(struct iommu *iommu);
 void hvm_dpci_isairq_eoi(struct domain *d, unsigned int isairq);
-struct hvm_irq_dpci *domain_get_irq_dpci(struct domain *domain);
-int domain_set_irq_dpci(struct domain *domain, struct hvm_irq_dpci *dpci);
+struct hvm_irq_dpci *domain_get_irq_dpci(const struct domain *);
 void free_hvm_irq_dpci(struct hvm_irq_dpci *dpci);
 bool_t pt_irq_need_timer(uint32_t flags);