Re: [PATCH 07/15] x86/hyperlaunch: initial support for hyperlaunch device tree

[Jason Andryuk]

On 2024-11-23 13:20, Daniel P. Smith wrote:
Add the ability to detect both a formal hyperlaunch device tree or a dom0less
device tree. If the hyperlaunch device tree is found, then count the number of
domain entries, reporting if more than one is found.
Signed-off-by: Daniel P. Smith <dpsm...@apertussolutions.com>
---
  xen/arch/x86/domain_builder/core.c  | 14 +++++++
  xen/arch/x86/domain_builder/fdt.c   | 64 ++++++++++++++++++++++++++++-
  xen/arch/x86/domain_builder/fdt.h   |  5 +++
  xen/arch/x86/include/asm/bootinfo.h |  1 +
  4 files changed, 83 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/domain_builder/core.c 
b/xen/arch/x86/domain_builder/core.c
index 211359895d84..a80f3711c306 100644
--- a/xen/arch/x86/domain_builder/core.c
+++ b/xen/arch/x86/domain_builder/core.c
@@ -40,7 +40,21 @@ void __init builder_init(struct boot_info *bi)
                     ret);
              bi->hyperlaunch_enabled = false;
          }
+    }
+
+    if ( bi->hyperlaunch_enabled )
+    {
+        int ret;
+
+        printk(XENLOG_INFO "Hyperlauch configuration:\n");

Hyperlaunch

+        if ( (ret = walk_hyperlaunch_fdt(bi)) < 0 )
+        {
+            printk(XENLOG_INFO "  walk of device tree failed (%d)\n", ret);
+            bi->hyperlaunch_enabled = false;
+            return;
+        }
  
+        printk(XENLOG_INFO "  Number of domains: %d\n", bi->nr_domains);
      }
  }
  
diff --git a/xen/arch/x86/domain_builder/fdt.c b/xen/arch/x86/domain_builder/fdt.c
index 3f9dda8c34c3..ff1ba58b6907 100644
--- a/xen/arch/x86/domain_builder/fdt.c
+++ b/xen/arch/x86/domain_builder/fdt.c

+int __init walk_hyperlaunch_fdt(struct boot_info *bi)
+{
+    int ret = 0, hv_node, node;
+    void *fdt = bootstrap_map_bm(&bi->mods[HYPERLAUNCH_MODULE_IDX]);
+
+    if ( unlikely(!fdt) )
+        return -EINVAL;
+
+    hv_node = find_hyperlaunch_node(fdt);
+    if ( hv_node < 0 )
+    {
+        ret = hv_node;
+        goto err_out;
+    }
+
+    fdt_for_each_subnode(node, fdt, hv_node)
+    {
+        ret = fdt_node_check_compatible(fdt, node, "xen,domain");
+        if ( ret == 0 )
+            bi->nr_domains++;
+    }
+
+    /* Until multi-domain construction is added, throw an error */
+    if ( !bi->nr_domains || bi->nr_domains > 1 )
+        printk(XENLOG_ERR "Hyperlaunch only supports dom0 construction\n");

You continue execution - is that intended?  It'll take the next module 
as the kernel and try to boot?  Would you rather panic?

Regards,
Jason

  
+ err_out:
      bootstrap_unmap();
  
      return ret;