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, 19 insertions, 10 deletions

diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 792e80f8ad..787aaa30ab 100644
--- 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;