[PATCH v2] xen/arm: check on domain type against hardware support

[vijay.kilari@gmail.com]

From: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>

Some arm64 platforms implement only aarch64 mode. So allow
domains that are only 64-bit

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
---
v2:-Fixed coding style comments
   -Make cpu_has_aarch32 check for both A32 and T32
   -Updated aarch32 capabilities info print
---
 xen/arch/arm/arm64/domctl.c      |    3 +++
 xen/arch/arm/domain_build.c      |    7 +++++++
 xen/arch/arm/setup.c             |   10 +++++++---
 xen/include/asm-arm/cpufeature.h |    3 ++-
 4 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/xen/arch/arm/arm64/domctl.c b/xen/arch/arm/arm64/domctl.c
index 41e2562..c0ff248 100644
--- a/xen/arch/arm/arm64/domctl.c
+++ b/xen/arch/arm/arm64/domctl.c
@@ -11,6 +11,7 @@
 #include <xen/sched.h>
 #include <xen/hypercall.h>
 #include <public/domctl.h>
+#include <asm/cpufeature.h>
 
 static long switch_mode(struct domain *d, enum domain_type type)
 {
@@ -35,6 +36,8 @@ long subarch_do_domctl(struct xen_domctl *domctl, struct domain *d,
         switch ( domctl->u.address_size.size )
         {
         case 32:
+            if ( !cpu_has_el1_32 )
+                return -EINVAL;
             return switch_mode(d, DOMAIN_32BIT);
         case 64:
             return switch_mode(d, DOMAIN_64BIT);
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 90abc3a..138ca89 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -17,6 +17,7 @@
 #include <asm/platform.h>
 #include <asm/psci.h>
 #include <asm/setup.h>
+#include <asm/cpufeature.h>
 
 #include <asm/gic.h>
 #include <xen/irq.h>
@@ -1274,6 +1275,12 @@ int construct_dom0(struct domain *d)
         return rc;
 
 #ifdef CONFIG_ARM_64
+    /* if aarch32 mode is not supported at EL1 do not allow 32-bit domain */
+    if ( !(cpu_has_el1_32) && kinfo.type == DOMAIN_32BIT )
+    {
+        printk("Platform does not support 32-bit domain\n");
+        return -EINVAL;
+    }
     d->arch.type = kinfo.type;
 #endif
 
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 446de8a..ceb5af8 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -127,8 +127,9 @@ static void __init processor_id(void)
         printk("32-bit Execution:\n");
         printk("  Processor Features: %08"PRIx32":%08"PRIx32"\n",
                boot_cpu_data.pfr32.bits[0], boot_cpu_data.pfr32.bits[1]);
-        printk("    Instruction Sets:%s%s%s%s%s\n",
+        printk("    Instruction Sets:%s%s%s%s%s%s\n",
                cpu_has_aarch32 ? " AArch32" : "",
+               cpu_has_a32 ? " A32" : "",
                cpu_has_thumb ? " Thumb" : "",
                cpu_has_thumb2 ? " Thumb-2" : "",
                cpu_has_thumbee ? " ThumbEE" : "",
@@ -851,8 +852,11 @@ void arch_get_xen_caps(xen_capabilities_info_t *info)
     snprintf(s, sizeof(s), "xen-%d.%d-aarch64 ", major, minor);
     safe_strcat(*info, s);
 #endif
-    snprintf(s, sizeof(s), "xen-%d.%d-armv7l ", major, minor);
-    safe_strcat(*info, s);
+    if ( cpu_has_aarch32 )
+    {
+        snprintf(s, sizeof(s), "xen-%d.%d-armv7l ", major, minor);
+        safe_strcat(*info, s);
+    }
 }
 
 /*
diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
index 7a6d3de..e605bf5 100644
--- a/xen/include/asm-arm/cpufeature.h
+++ b/xen/include/asm-arm/cpufeature.h
@@ -21,11 +21,12 @@
 #define cpu_feature32(c, feat)         ((c)->pfr32.feat)
 #define boot_cpu_feature32(feat)       (boot_cpu_data.pfr32.feat)
 
-#define cpu_has_aarch32   (boot_cpu_feature32(arm) == 1)
+#define cpu_has_a32       (boot_cpu_feature32(arm) == 1)
 #define cpu_has_thumb     (boot_cpu_feature32(thumb) >= 1)
 #define cpu_has_thumb2    (boot_cpu_feature32(thumb) >= 3)
 #define cpu_has_jazelle   (boot_cpu_feature32(jazelle) >= 0)
 #define cpu_has_thumbee   (boot_cpu_feature32(thumbee) == 1)
+#define cpu_has_aarch32   (cpu_has_a32 || cpu_has_thumb)
 
 #ifdef CONFIG_ARM_32
 #define cpu_has_gentimer  (boot_cpu_feature32(gentimer) == 1)
-- 
1.7.9.5