[PATCH v4 13/13] x86/hyperlaunch: add capabilities to boot domain

[Alejandro Vallejo <agarciav@xxxxxxx>]

From: "Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>

Introduce the ability to assign capabilities to a domain via its definition in
device tree. The first capability enabled to select is the control domain
capability. The capability property is a bitfield in both the device tree and
`struct boot_domain`.

Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jason Andryuk <jason.andryuk@xxxxxxx>
Signed-off-by: Alejandro Vallejo <agarciav@xxxxxxx>
---
v4:
  * Dropped Jason's R-by.
  * Refactored caps printinng logic
    * It just wasn't xenlog-compatible as it was.
  * Moved pv_shim check to builder_init, so the capability is just not given.
    * And inlined the create_flags variable now that's tractable.
  * Validated input capabilities after coming out of the DT.
---
 xen/arch/x86/include/asm/boot-domain.h |  5 +++++
 xen/arch/x86/setup.c                   |  3 ++-
 xen/common/domain-builder/core.c       |  2 ++
 xen/common/domain-builder/fdt.c        | 20 ++++++++++++++++++++
 4 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/include/asm/boot-domain.h 
b/xen/arch/x86/include/asm/boot-domain.h
index 969c02a6ea..5c143d82af 100644
--- a/xen/arch/x86/include/asm/boot-domain.h
+++ b/xen/arch/x86/include/asm/boot-domain.h
@@ -13,6 +13,11 @@
 struct boot_domain {
     domid_t domid;
 
+#define BUILD_CAPS_NONE          (0U)
+#define BUILD_CAPS_CONTROL       (1U << 0)
+#define BUILD_CAPS__ALL          BUILD_CAPS_CONTROL
+    uint32_t capabilities;
+
                                           /* On     | Off    */
 #define BUILD_MODE_PARAVIRT      (1 << 0) /* PV     | PVH/HVM */
 #define BUILD_MODE_ENABLE_DM     (1 << 1) /* HVM    | PVH     */
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 455dad454c..3cdd8bc2f9 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1040,7 +1040,8 @@ static struct domain *__init create_dom0(struct boot_info 
*bi)
     if ( bd->domid == DOMID_INVALID )
         /* Create initial domain.  Not d0 for pvshim. */
         bd->domid = get_initial_domain_id();
-    d = domain_create(bd->domid, &dom0_cfg, pv_shim ? 0 : CDF_privileged);
+    d = domain_create(bd->domid, &dom0_cfg,
+            (bd->capabilities & BUILD_CAPS_CONTROL) ? CDF_privileged : 0);
     if ( IS_ERR(d) )
         panic("Error creating d%u: %ld\n", bd->domid, PTR_ERR(d));
 
diff --git a/xen/common/domain-builder/core.c b/xen/common/domain-builder/core.c
index 4b4230f2ff..d1a5d6125e 100644
--- a/xen/common/domain-builder/core.c
+++ b/xen/common/domain-builder/core.c
@@ -8,6 +8,7 @@
 #include <xen/lib.h>
 
 #include <asm/bootinfo.h>
+#include <asm/pv/shim.h>
 #include <asm/setup.h>
 
 #include "fdt.h"
@@ -93,6 +94,7 @@ void __init builder_init(struct boot_info *bi)
 
         bi->mods[i].type = BOOTMOD_KERNEL;
         bi->domains[0].kernel = &bi->mods[i];
+        bi->domains[0].capabilities |= pv_shim ? 0 : BUILD_CAPS_CONTROL;
         bi->nr_domains = 1;
     }
 }
diff --git a/xen/common/domain-builder/fdt.c b/xen/common/domain-builder/fdt.c
index 295ab6e8b3..3e3a84e2d0 100644
--- a/xen/common/domain-builder/fdt.c
+++ b/xen/common/domain-builder/fdt.c
@@ -293,6 +293,26 @@ static int __init process_domain_node(
             bd->max_vcpus = val;
             printk(XENLOG_INFO "  cpus: %d\n", bd->max_vcpus);
         }
+        else if ( !strncmp(prop_name, "capabilities", name_len) )
+        {
+            if ( (rc = fdt_prop_as_u32(prop, &bd->capabilities)) )
+            {
+                printk(XENLOG_ERR
+                       "  bad \"capabilities\" on domain %s\n", name);
+                return rc;
+            }
+
+            if ( bd->capabilities & ~BUILD_CAPS__ALL )
+            {
+                printk(XENLOG_WARNING "  unknown capabilities: %#x\n",
+                       bd->capabilities & ~BUILD_CAPS__ALL);
+
+                bd->capabilities &= BUILD_CAPS__ALL;
+            }
+
+            printk(XENLOG_INFO "  caps: %s\n",
+                   bd->capabilities & BUILD_CAPS_CONTROL ? "c" : "");
+        }
     }
 
     fdt_for_each_subnode(node, fdt, dom_node)
-- 
2.43.0