Add a domid field to struct boot_domain to hold the assigned domain id for the
domain. During initialization, ensure all instances of struct boot_domain have
the invalid domid to ensure that the domid must be set either by convention or
configuration.

Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
---
Changes since v9 boot modules
- missing include for domid_t def
---
 xen/arch/x86/include/asm/bootdomain.h |  4 ++++
 xen/arch/x86/setup.c                  | 12 +++++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/xen/arch/x86/include/asm/bootdomain.h b/xen/arch/x86/include/asm/bootdomain.h
index 12c19ab37bd8..bcbf36b13f25 100644
--- a/xen/arch/x86/include/asm/bootdomain.h
+++ b/xen/arch/x86/include/asm/bootdomain.h
@@ -5,6 +5,8 @@
  * Copyright (c) 2024 Christopher Clark <christopher.w.clark@gmail.com>
  */
 
+#include <public/xen.h>
+
 #ifndef __XEN_X86_BOOTDOMAIN_H__
 #define __XEN_X86_BOOTDOMAIN_H__
 
@@ -12,6 +14,8 @@ struct boot_module;
 struct domain;
 
 struct boot_domain {
+    domid_t domid;
+
     struct boot_module *kernel;
     struct boot_module *ramdisk;
 
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 460157def8ea..a2178d5e8cc5 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -339,6 +339,9 @@ static struct boot_info *__init multiboot_fill_boot_info(
     /* Variable 'i' should be one entry past the last module. */
     bi->mods[i].type = BOOTMOD_XEN;
 
+    for ( i = 0; i < MAX_NR_BOOTDOMS; i++ )
+        bi->domains[i].domid = DOMID_INVALID;
+
     return bi;
 }
 
@@ -979,7 +982,6 @@ static struct domain *__init create_dom0(struct boot_info *bi)
     };
     struct boot_domain *bd = &bi->domains[0];
     struct domain *d;
-    domid_t domid;
 
     if ( opt_dom0_pvh )
     {
@@ -995,15 +997,15 @@ static struct domain *__init create_dom0(struct boot_info *bi)
         dom0_cfg.flags |= XEN_DOMCTL_CDF_iommu;
 
     /* Create initial domain.  Not d0 for pvshim. */
-    domid = get_initial_domain_id();
-    d = domain_create(domid, &dom0_cfg, pv_shim ? 0 : CDF_privileged);
+    bd->domid = get_initial_domain_id();
+    d = domain_create(bd->domid, &dom0_cfg, pv_shim ? 0 : CDF_privileged);
     if ( IS_ERR(d) )
-        panic("Error creating d%u: %ld\n", domid, PTR_ERR(d));
+        panic("Error creating d%u: %ld\n", bd->domid, PTR_ERR(d));
 
     init_dom0_cpuid_policy(d);
 
     if ( alloc_dom0_vcpu0(d) == NULL )
-        panic("Error creating d%uv0\n", domid);
+        panic("Error creating d%uv0\n", bd->domid);
 
     /* Grab the DOM0 command line. */
     if ( bd->kernel->cmdline_pa || bi->kextra )
-- 
2.30.2