[PATCH v4 2/9] xen: add generic flag to elf_dom_parms indicating support of unmapped initrd

[Juergen Gross <jgross@suse.com>]

Support of an unmapped initrd is indicated by the kernel of the domain
via elf notes. In order not to have to use raw elf data in the tools
for support of an unmapped initrd add a flag to the parsed data area
to indicate the kernel supporting this feature.

Switch using this flag in the hypervisor domain builder.

Cc: andrew.cooper3@citrix.com
Cc: jbeulich@suse.com
Cc: keir@xen.org
Suggested-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
 xen/arch/x86/domain_build.c        | 4 ++--
 xen/common/libelf/libelf-dominfo.c | 3 +++
 xen/include/xen/libelf.h           | 1 +
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c
index c2ef87a..d02dc4b 100644
--- a/xen/arch/x86/domain_build.c
+++ b/xen/arch/x86/domain_build.c
@@ -353,7 +353,7 @@ static unsigned long __init compute_dom0_nr_pages(
 
         vstart = parms->virt_base;
         vend = round_pgup(parms->virt_kend);
-        if ( !parms->elf_notes[XEN_ELFNOTE_MOD_START_PFN].data.num )
+        if ( !parms->unmapped_initrd )
             vend += round_pgup(initrd_len);
         end = vend + nr_pages * sizeof_long;
 
@@ -1037,7 +1037,7 @@ int __init construct_dom0(
     v_start          = parms.virt_base;
     vkern_start      = parms.virt_kstart;
     vkern_end        = parms.virt_kend;
-    if ( parms.elf_notes[XEN_ELFNOTE_MOD_START_PFN].data.num )
+    if ( parms.unmapped_initrd )
     {
         vinitrd_start  = vinitrd_end = 0;
         vphysmap_start = round_pgup(vkern_end);
diff --git a/xen/common/libelf/libelf-dominfo.c b/xen/common/libelf/libelf-dominfo.c
index 3de1c23..c9243e4 100644
--- a/xen/common/libelf/libelf-dominfo.c
+++ b/xen/common/libelf/libelf-dominfo.c
@@ -190,6 +190,9 @@ elf_errorstatus elf_xen_parse_note(struct elf_binary *elf,
     case XEN_ELFNOTE_INIT_P2M:
         parms->p2m_base = val;
         break;
+    case XEN_ELFNOTE_MOD_START_PFN:
+        parms->unmapped_initrd = !!val;
+        break;
     case XEN_ELFNOTE_PADDR_OFFSET:
         parms->elf_paddr_offset = val;
         break;
diff --git a/xen/include/xen/libelf.h b/xen/include/xen/libelf.h
index de788c7..6da4cc0 100644
--- a/xen/include/xen/libelf.h
+++ b/xen/include/xen/libelf.h
@@ -423,6 +423,7 @@ struct elf_dom_parms {
     char loader[16];
     enum xen_pae_type pae;
     bool bsd_symtab;
+    bool unmapped_initrd;
     uint64_t virt_base;
     uint64_t virt_entry;
     uint64_t virt_hypercall;
-- 
2.1.4