Add XENVER_get_features sub-operation to HYPERVISOR_xen_version.

This operation allows a guest OS to determine which features are
supported by the running version of Xen. This changeset contains the
base infrastructure but does not implement any features yet.

Signed-off-by: Ian Campbell <Ian.Campbell@XenSource.com>
Index: xen-features/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c
===================================================================
--- xen-features.orig/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c	2006-01-27 11:13:22.000000000 +0000
+++ xen-features/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c	2006-01-27 11:27:14.000000000 +0000
@@ -56,6 +56,7 @@
 #include <asm/hypervisor.h>
 #include <asm-xen/xen-public/physdev.h>
 #include <asm-xen/xen-public/memory.h>
+#include <asm-xen/features.h>
 #include "setup_arch_pre.h"
 #include <bios_ebda.h>

@@ -1591,6 +1592,9 @@
 	rd_prompt = ((RAMDISK_FLAGS & RAMDISK_PROMPT_FLAG) != 0);
 	rd_doload = ((RAMDISK_FLAGS & RAMDISK_LOAD_FLAG) != 0);
 #endif
+
+	setup_xen_features();
+
 	ARCH_SETUP
 	if (efi_enabled)
 		efi_init();
Index: xen-features/linux-2.6-xen-sparse/arch/xen/x86_64/kernel/setup.c
===================================================================
--- xen-features.orig/linux-2.6-xen-sparse/arch/xen/x86_64/kernel/setup.c	2006-01-27 11:13:22.000000000 +0000
+++ xen-features/linux-2.6-xen-sparse/arch/xen/x86_64/kernel/setup.c	2006-01-27 11:27:14.000000000 +0000
@@ -63,6 +63,7 @@
 #include "setup_arch_pre.h"
 #include <asm/hypervisor.h>
 #include <asm-xen/xen-public/nmi.h>
+#include <asm-xen/features.h>
 #define PFN_UP(x)       (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
 #define PFN_PHYS(x)     ((x) << PAGE_SHIFT)
 #define end_pfn_map end_pfn
@@ -587,6 +588,8 @@

 #endif

+	setup_xen_features();
+
 	HYPERVISOR_vm_assist(VMASST_CMD_enable,
 			     VMASST_TYPE_writable_pagetables);

Index: xen-features/linux-2.6-xen-sparse/include/asm-xen/features.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ xen-features/linux-2.6-xen-sparse/include/asm-xen/features.h	2006-01-27 11:27:14.000000000 +0000
@@ -0,0 +1,20 @@
+/******************************************************************************
+ * features.h
+ *
+ * Query the features reported by Xen.
+ *
+ * Copyright (c) 2006, Ian Campbell
+ */
+
+#ifndef __ASM_XEN_FEATURES_H__
+#define __ASM_XEN_FEATURES_H__
+
+#include <asm-xen/xen-public/version.h>
+
+extern void setup_xen_features(void);
+
+extern unsigned long xen_features[XENFEAT_NR_SUBMAPS];
+
+#define xen_feature(flag)	(test_bit(_XENFEAT_ ## flag, xen_features))
+
+#endif
Index: xen-features/xen/common/kernel.c
===================================================================
--- xen-features.orig/xen/common/kernel.c	2006-01-27 11:13:22.000000000 +0000
+++ xen-features/xen/common/kernel.c	2006-01-27 11:27:34.000000000 +0000
@@ -144,6 +144,28 @@
             return -EFAULT;
         return 0;
     }
+
+    case XENVER_get_features:
+    {
+        xen_feature_info_t fi;
+
+        if ( copy_from_user(&fi, arg, sizeof(fi)) )
+            return -EFAULT;
+
+        switch ( fi.submap_idx )
+        {
+        case 0:
+            fi.submap = 0;
+            break;
+        default:
+            return -EINVAL;
+        }
+
+        if ( copy_to_user(arg, &fi, sizeof(fi)) )
+            return -EFAULT;
+        return 0;
+    }
+
     }

     return -ENOSYS;
Index: xen-features/xen/include/public/version.h
===================================================================
--- xen-features.orig/xen/include/public/version.h	2006-01-27 11:13:22.000000000 +0000
+++ xen-features/xen/include/public/version.h	2006-01-27 11:27:22.000000000 +0000
@@ -39,6 +39,14 @@
     unsigned long virt_start;
 } xen_platform_parameters_t;

+#define XENVER_get_features 6
+typedef struct xen_feature_info {
+    unsigned int submap_idx;    /* IN: which 32-bit submap to return */
+    uint32_t     submap;        /* OUT: 32-bit submap */
+} xen_feature_info_t;
+
+#define XENFEAT_NR_SUBMAPS 1
+
 #endif /* __XEN_PUBLIC_VERSION_H__ */

 /*
Index: xen-features/linux-2.6-xen-sparse/arch/xen/kernel/features.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ xen-features/linux-2.6-xen-sparse/arch/xen/kernel/features.c	2006-01-27 11:27:14.000000000 +0000
@@ -0,0 +1,29 @@
+/******************************************************************************
+ * features.c
+ *
+ * Xen feature flags.
+ *
+ * Copyright (c) 2006, Ian Campbell
+ */
+#include <linux/types.h>
+#include <linux/cache.h>
+#include <asm/hypervisor.h>
+#include <asm-xen/features.h>
+
+/* When we rebase to a more recent version of Linux we can use __read_mostly here. */
+unsigned long xen_features[XENFEAT_NR_SUBMAPS] __cacheline_aligned;
+
+void setup_xen_features(void)
+{
+     uint32_t *flags = (uint32_t *)&xen_features[0];
+     xen_feature_info_t fi;
+     int i;
+
+     for (i=0; i<XENFEAT_NR_SUBMAPS; i++) {
+	  fi.submap_idx = i;
+	  if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0)
+	       break;
+	  flags[i] = fi.submap;
+     }
+}
+

diff --git a/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c b/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c
index aeef736bd30b05b2377852f2fa4f3833167e8781..df8c72221f58f850aff7b0d260b955e3fc0bc311 100644 (file)
--- a/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c
+++ b/linux-2.6-xen-sparse/arch/xen/i386/kernel/setup.c
@@ -56,6 +56,7 @@
 #include <asm/hypervisor.h>
 #include <asm-xen/xen-public/physdev.h>
 #include <asm-xen/xen-public/memory.h>
+#include <asm-xen/features.h>
 #include "setup_arch_pre.h"
 #include <bios_ebda.h>
 
@@ -1591,6 +1592,9 @@ void __init setup_arch(char **cmdline_p)
        rd_prompt = ((RAMDISK_FLAGS & RAMDISK_PROMPT_FLAG) != 0);
        rd_doload = ((RAMDISK_FLAGS & RAMDISK_LOAD_FLAG) != 0);
 #endif
+
+       setup_xen_features();
+
        ARCH_SETUP
        if (efi_enabled)
                efi_init();

diff --git a/linux-2.6-xen-sparse/arch/xen/kernel/features.c b/linux-2.6-xen-sparse/arch/xen/kernel/features.c
new file mode 100644 (file)
index 0000000..6a7315f
--- /dev/null
+++ b/linux-2.6-xen-sparse/arch/xen/kernel/features.c
@@ -0,0 +1,29 @@
+/******************************************************************************
+ * features.c
+ *
+ * Xen feature flags.
+ *
+ * Copyright (c) 2006, Ian Campbell
+ */
+#include <linux/types.h>
+#include <linux/cache.h>
+#include <asm/hypervisor.h>
+#include <asm-xen/features.h>
+
+/* When we rebase to a more recent version of Linux we can use __read_mostly here. */
+unsigned long xen_features[XENFEAT_NR_SUBMAPS] __cacheline_aligned;
+
+void setup_xen_features(void)
+{
+     uint32_t *flags = (uint32_t *)&xen_features[0];
+     xen_feature_info_t fi;
+     int i;
+
+     for (i=0; i<XENFEAT_NR_SUBMAPS; i++) {
+         fi.submap_idx = i;
+         if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0)
+              break;
+         flags[i] = fi.submap;
+     }
+}
+

diff --git a/linux-2.6-xen-sparse/arch/xen/x86_64/kernel/setup.c b/linux-2.6-xen-sparse/arch/xen/x86_64/kernel/setup.c
index ef7deb8938b1b523dffb992e3fcc1072500bd83d..2e20185ab361a26bbcb1fcc130e57a80a919f352 100644 (file)
--- a/linux-2.6-xen-sparse/arch/xen/x86_64/kernel/setup.c
+++ b/linux-2.6-xen-sparse/arch/xen/x86_64/kernel/setup.c
@@ -63,6 +63,7 @@
 #include "setup_arch_pre.h"
 #include <asm/hypervisor.h>
 #include <asm-xen/xen-public/nmi.h>
+#include <asm-xen/features.h>
 #define PFN_UP(x)       (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
 #define PFN_PHYS(x)     ((x) << PAGE_SHIFT)
 #define end_pfn_map end_pfn
@@ -587,6 +588,8 @@ void __init setup_arch(char **cmdline_p)
 
 #endif
 
+       setup_xen_features();
+
        HYPERVISOR_vm_assist(VMASST_CMD_enable,
                             VMASST_TYPE_writable_pagetables);
 

diff --git a/linux-2.6-xen-sparse/include/asm-xen/features.h b/linux-2.6-xen-sparse/include/asm-xen/features.h
new file mode 100644 (file)
index 0000000..ffe893f
--- /dev/null
+++ b/linux-2.6-xen-sparse/include/asm-xen/features.h
@@ -0,0 +1,20 @@
+/******************************************************************************
+ * features.h
+ *
+ * Query the features reported by Xen.
+ *
+ * Copyright (c) 2006, Ian Campbell
+ */
+
+#ifndef __ASM_XEN_FEATURES_H__
+#define __ASM_XEN_FEATURES_H__
+
+#include <asm-xen/xen-public/version.h>
+
+extern void setup_xen_features(void);
+
+extern unsigned long xen_features[XENFEAT_NR_SUBMAPS];
+
+#define xen_feature(flag)      (test_bit(_XENFEAT_ ## flag, xen_features))
+
+#endif

diff --git a/xen/common/kernel.c b/xen/common/kernel.c
index f1d74c731aa34bd9cf331b03ed2364c2abf422e1..3a4e420bc1336c91abe14c0ef7d299d1e3107535 100644 (file)
--- a/xen/common/kernel.c
+++ b/xen/common/kernel.c
@@ -144,6 +144,28 @@ long do_xen_version(int cmd, void *arg)
             return -EFAULT;
         return 0;
     }
+
+    case XENVER_get_features:
+    {
+        xen_feature_info_t fi;
+
+        if ( copy_from_user(&fi, arg, sizeof(fi)) )
+            return -EFAULT;
+
+        switch ( fi.submap_idx )
+        {
+        case 0:
+            fi.submap = 0;
+            break;
+        default:
+            return -EINVAL;
+        }
+
+        if ( copy_to_user(arg, &fi, sizeof(fi)) )
+            return -EFAULT;
+        return 0;
+    }
+
     }
 
     return -ENOSYS;

diff --git a/xen/include/public/version.h b/xen/include/public/version.h
index d22566e38112d0dbca96affe523b33b99706ea1f..8259f1856f8c4307768186e195c432bc33306c6d 100644 (file)
--- a/xen/include/public/version.h
+++ b/xen/include/public/version.h
@@ -39,6 +39,14 @@ typedef struct xen_platform_parameters {
     unsigned long virt_start;
 } xen_platform_parameters_t;
 
+#define XENVER_get_features 6
+typedef struct xen_feature_info {
+    unsigned int submap_idx;    /* IN: which 32-bit submap to return */
+    uint32_t     submap;        /* OUT: 32-bit submap */
+} xen_feature_info_t;
+
+#define XENFEAT_NR_SUBMAPS 1
+
 #endif /* __XEN_PUBLIC_VERSION_H__ */
 
 /*