@@ -200,23 +200,20 @@ config XENOPROF
If unsure, say Y.
-config XSM
- bool "Xen Security Modules support"
+config XSM_CONFIGURABLE
+ bool "Configure Xen Security Modules"
default ARM
- ---help---
- Enables the security framework known as Xen Security Modules which
- allows administrators fine-grained control over a Xen domain and
- its capabilities by defining permissible interactions between domains,
- the hypervisor itself, and related resources such as memory and
- devices.
+ help
+ Allows for configuring the Xen Security Modules (XSM) policy or policies
+ modules that will be availble and which will be the default.
If unsure, say N.
config XSM_FLASK
- def_bool y
- prompt "FLux Advanced Security Kernel support"
- depends on XSM
- ---help---
+ bool "FLux Advanced Security Kernel support"
+ depends on XSM_CONFIGURABLE
+ select XSM_EVTCHN_LABELING
+ help
Enables FLASK (FLux Advanced Security Kernel) as the access control
mechanism used by the XSM framework. This provides a mandatory access
control framework by which security enforcement, isolation, and
@@ -226,10 +223,10 @@ config XSM_FLASK
If unsure, say Y.
config XSM_FLASK_AVC_STATS
- def_bool y
- prompt "Maintain statistics on the FLASK access vector cache" if EXPERT
+ bool "Maintain statistics on the FLASK access vector cache" if EXPERT
+ default y
depends on XSM_FLASK
- ---help---
+ help
Maintain counters on the access vector cache that can be viewed using
the FLASK_AVC_CACHESTATS sub-op of the xsm_op hypercall. Disabling
this will save a tiny amount of memory and time to update the stats.
@@ -240,7 +237,7 @@ config XSM_FLASK_POLICY
bool "Compile Xen with a built-in FLASK security policy"
default y if "$(XEN_HAS_CHECKPOLICY)" = "y"
depends on XSM_FLASK
- ---help---
+ help
This includes a default XSM policy in the hypervisor so that the
bootloader does not need to load a policy to get sane behavior from an
XSM-enabled hypervisor. If this is disabled, a policy must be
@@ -253,10 +250,10 @@ config XSM_FLASK_POLICY
If unsure, say Y.
config XSM_SILO
- def_bool y
- prompt "SILO support"
- depends on XSM
- ---help---
+ bool "SILO support"
+ default y if ARM
+ depends on XSM_CONFIGURABLE
+ help
Enables SILO as the access control mechanism used by the XSM framework.
This is not the default module, add boot parameter xsm=silo to choose
it. This will deny any unmediated communication channels (grant tables
@@ -265,14 +262,14 @@ config XSM_SILO
If unsure, say Y.
choice
- prompt "Default XSM implementation"
- depends on XSM
+ prompt "Default XSM module"
+ depends on XSM_CONFIGURABLE
default XSM_SILO_DEFAULT if XSM_SILO && ARM
default XSM_FLASK_DEFAULT if XSM_FLASK
default XSM_SILO_DEFAULT if XSM_SILO
default XSM_DUMMY_DEFAULT
config XSM_DUMMY_DEFAULT
- bool "Match non-XSM behavior"
+ bool "Classic Dom0 behavior"
config XSM_FLASK_DEFAULT
bool "FLux Advanced Security Kernel" if XSM_FLASK
config XSM_SILO_DEFAULT
@@ -282,15 +279,15 @@ endchoice
config LATE_HWDOM
bool "Dedicated hardware domain"
default n
- depends on XSM && X86
- ---help---
+ depends on XSM_FLASK && X86
+ help
Allows the creation of a dedicated hardware domain distinct from
domain 0 that manages devices without needing access to other
privileged functionality such as the ability to manage domains.
This requires that the actual domain 0 be a stub domain that
constructs the actual hardware domain instead of initializing the
hardware itself. Because the hardware domain needs access to
- hypercalls not available to unprivileged guests, an XSM policy
+ hypercalls not available to unprivileged guests, an XSM Flask policy
is required to properly define the privilege of these domains.
This feature does nothing if the "hardware_dom" boot parameter is
@@ -120,7 +120,7 @@ struct evtchn
unsigned short notify_vcpu_id; /* VCPU for local delivery notification */
uint32_t fifo_lastq; /* Data for identifying last queue. */
-#ifdef CONFIG_XSM
+#ifdef CONFIG_XSM_CONFIGURABLE
union {
/*
* If an XSM module needs more space for its event channel context,
@@ -42,12 +42,12 @@ static inline void __xsm_action_mismatch_detected(void)
void __xsm_action_mismatch_detected(void);
#endif
-#ifdef CONFIG_XSM
+#ifdef CONFIG_XSM_CONFIGURABLE
-/* In CONFIG_XSM builds, this header file is included from xsm/dummy.c, and
- * contains static (not inline) functions compiled to the dummy XSM module.
- * There is no xsm_default_t argument available, so the value from the assertion
- * is used to initialize the variable.
+/* In CONFIG_XSM_CONFIGURABLE builds, this header file is included from
+ * xsm/dummy.c, and contains static (not inline) functions compiled to the
+ * dummy XSM module. There is no xsm_default_t argument available, so the
+ * value from the assertion is used to initialize the variable.
*/
#define XSM_INLINE __maybe_unused
@@ -55,19 +55,20 @@ void __xsm_action_mismatch_detected(void);
#define XSM_DEFAULT_VOID void
#define XSM_ASSERT_ACTION(def) xsm_default_t action = def; (void)action
-#else /* CONFIG_XSM */
+#else /* CONFIG_XSM_CONFIGURABLE */
-/* In !CONFIG_XSM builds, this header file is included from xsm/xsm.h, and
- * contains inline functions for each XSM hook. These functions also perform
- * compile-time checks on the xsm_default_t argument to ensure that the behavior
- * of the dummy XSM module is the same as the behavior with XSM disabled.
+/* In !CONFIG_XSM_CONFIGURABLE builds, this header file is included from
+ * xsm/xsm.h, and contains inline functions for each XSM hook. These functions
+ * also perform compile-time checks on the xsm_default_t argument to ensure
+ * that the behavior of the dummy XSM module is the same as the behavior with
+ * XSM disabled.
*/
#define XSM_INLINE always_inline
#define XSM_DEFAULT_ARG xsm_default_t action,
#define XSM_DEFAULT_VOID xsm_default_t action
#define XSM_ASSERT_ACTION(def) LINKER_BUG_ON(def != action)
-#endif /* CONFIG_XSM */
+#endif /* CONFIG_XSM_CONFIGURABLE */
static always_inline int xsm_default_action(xsm_default_t action,
struct domain *src,
@@ -205,7 +205,7 @@ struct xsm_ops {
void xsm_fixup_ops(struct xsm_ops *ops);
-#ifdef CONFIG_XSM
+#ifdef CONFIG_XSM_CONFIGURABLE
#ifdef CONFIG_MULTIBOOT
int xsm_multiboot_init(unsigned long *module_map,
@@ -247,7 +247,7 @@ static const inline struct xsm_ops *silo_init(void)
}
#endif
-#else /* CONFIG_XSM */
+#else /* CONFIG_XSM_CONFIGURABLE */
#ifdef CONFIG_MULTIBOOT
static inline int xsm_multiboot_init(unsigned long *module_map,
@@ -269,6 +269,6 @@ static inline bool has_xsm_magic(paddr_t start)
}
#endif /* CONFIG_HAS_DEVICE_TREE */
-#endif /* CONFIG_XSM */
+#endif /* CONFIG_XSM_CONFIGURABLE */
#endif /* __XSM_CORE_H */
@@ -20,7 +20,7 @@
#include <xen/multiboot.h>
#include <xsm/xsm-core.h>
-#ifdef CONFIG_XSM
+#ifdef CONFIG_XSM_CONFIGURABLE
extern struct xsm_ops xsm_ops;
@@ -598,10 +598,10 @@ static inline int xsm_argo_send(const struct domain *d, const struct domain *t)
#endif /* CONFIG_ARGO */
-#else /* CONFIG_XSM */
+#else /* CONFIG_XSM_CONFIGURABLE */
#include <xsm/dummy.h>
-#endif /* CONFIG_XSM */
+#endif /* CONFIG_XSM_CONFIGURABLE */
#endif /* __XSM_H */
@@ -1,6 +1,6 @@
obj-y += xsm_core.o
-obj-$(CONFIG_XSM) += xsm_policy.o
-obj-$(CONFIG_XSM) += dummy.o
+obj-$(CONFIG_XSM_CONFIGURABLE) += xsm_policy.o
+obj-$(CONFIG_XSM_CONFIGURABLE) += dummy.o
obj-$(CONFIG_XSM_SILO) += silo.o
obj-$(CONFIG_XSM_FLASK) += flask/
@@ -18,7 +18,7 @@
#include <xen/hypercall.h>
#include <xsm/xsm.h>
-#ifdef CONFIG_XSM
+#ifdef CONFIG_XSM_CONFIGURABLE
#ifdef CONFIG_MULTIBOOT
#include <asm/setup.h>
@@ -227,7 +227,7 @@ bool __init has_xsm_magic(paddr_t start)
}
#endif
-#endif
+#endif /* CONFIG_XSM_CONFIGURABLE */
long do_xsm_op(XEN_GUEST_HANDLE_PARAM(void) op)
{
It has been a very long time since XSM Flask was the only XSM module, yet the concenpt of turning XSM on/off continues to be synonymous with enabling and disabling XSM Flask. Even when XSM Flask was the only module, turning XSM on/off did not disable or remove the XSM hooks but simply controlled whether they were implemented as direct inline functions or dispatch calls. This commit updates XSM kconfig to ensure that it is clear in the code as well to the user, via the help messages, that the option is about configuring which XSM policy module(s) are available and which is the default. Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com> --- xen/common/Kconfig | 49 ++++++++++++++++++-------------------- xen/include/xen/sched.h | 2 +- xen/include/xsm/dummy.h | 23 +++++++++--------- xen/include/xsm/xsm-core.h | 6 ++--- xen/include/xsm/xsm.h | 6 ++--- xen/xsm/Makefile | 4 ++-- xen/xsm/xsm_core.c | 4 ++-- 7 files changed, 46 insertions(+), 48 deletions(-)