[RFC 32/38] x86/hyperlaunch: introduce concept of core domains

["Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>]

When constructing domU, and specifically the event channels for their console
and xenstore event channels, the domid for the backing domain must be known.
Therefore, the control, hardware, and xenstore domains are deemed as core
domains, and must be constructed before any of the other domains.

This commit introduces the build_core_domains() function that will ensure the
core domains are constructed first.

Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
---
 xen/arch/x86/domain-builder/core.c     | 68 ++++++++++++++++++++++++--
 xen/arch/x86/include/asm/boot-domain.h |  2 +
 2 files changed, 66 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/domain-builder/core.c 
b/xen/arch/x86/domain-builder/core.c
index 901efce62a61..f693aa46d278 100644
--- a/xen/arch/x86/domain-builder/core.c
+++ b/xen/arch/x86/domain-builder/core.c
@@ -103,18 +103,78 @@ void __init builder_init(struct boot_info *bi)
     }
 }
 
+static int  __init build_core_domains(struct boot_info *bi)
+{
+    int count = 0;
+    struct boot_domain *bd;
+    int hw, cd, xs;
+
+    cd = first_boot_domain_index(bi, BUILD_CAPS_CONTROL);
+    if ( cd > MAX_NR_BOOTDOMS )
+        printk(XENLOG_WARNING "No control domain was defined\n");
+    else
+    {
+        bd = &bi->domains[cd];
+
+        arch_create_dom(bi, bd);
+        if ( bd->d )
+        {
+            bd->constructed = true;
+            count++;
+        }
+    }
+
+    hw = first_boot_domain_index(bi, BUILD_CAPS_HARDWARE);
+    if ( hw > MAX_NR_BOOTDOMS )
+        printk(XENLOG_WARNING "No hardware domain was defined\n");
+    else
+    {
+        if ( hw != cd )
+        {
+            bd = &bi->domains[hw];
+
+            arch_create_dom(bi, bd);
+            if ( bd->d )
+            {
+                bd->constructed = true;
+                count++;
+            }
+        }
+    }
+
+    xs = first_boot_domain_index(bi, BUILD_CAPS_XENSTORE);
+    if ( xs > MAX_NR_BOOTDOMS )
+        printk(XENLOG_WARNING "No xenstore domain was defined\n");
+    else
+    {
+        if ( xs != cd && xs != hw )
+        {
+            bd = &bi->domains[xs];
+
+            arch_create_dom(bi, bd);
+            if ( bd->d )
+            {
+                bd->constructed = true;
+                count++;
+            }
+        }
+    }
+
+    return count;
+}
+
 unsigned int __init builder_create_domains(struct boot_info *bi)
 {
     unsigned int build_count = 0;
     struct boot_domain *bd = &bi->domains[0];
 
+    if ( bi->nr_domains == 0 )
+        panic("%s: no domains defined\n", __func__);
+
     if ( bd->kernel == NULL && bd->capabilities & BUILD_CAPS_CONTROL )
         panic("%s: control domain missing kernel\n", __func__);
 
-
-    arch_create_dom(bi, bd);
-    if ( bd->d )
-        build_count++;
+    build_count = build_core_domains(bi);
 
     /* Free temporary buffers. */
     free_boot_modules();
diff --git a/xen/arch/x86/include/asm/boot-domain.h 
b/xen/arch/x86/include/asm/boot-domain.h
index df2bfa0c94fa..a574f4941ed3 100644
--- a/xen/arch/x86/include/asm/boot-domain.h
+++ b/xen/arch/x86/include/asm/boot-domain.h
@@ -42,6 +42,8 @@ struct boot_domain {
         xen_pfn_t gfn;
         evtchn_port_t evtchn;
     } console, store;
+
+    bool constructed;
 };
 
 #endif
-- 
2.30.2