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-rw-r--r--arch/x86/include/asm/paravirt.h6
-rw-r--r--arch/x86/include/asm/paravirt_types.h5
-rw-r--r--arch/x86/include/asm/processor.h1
-rw-r--r--arch/x86/kernel/rtc.c3
-rw-r--r--arch/x86/lguest/boot.c1
-rw-r--r--arch/x86/xen/enlighten.c4
6 files changed, 19 insertions, 1 deletions
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 10d0596433f8..c759b3cca663 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -19,6 +19,12 @@ static inline int paravirt_enabled(void)
return pv_info.paravirt_enabled;
}
+static inline int paravirt_has_feature(unsigned int feature)
+{
+ WARN_ON_ONCE(!pv_info.paravirt_enabled);
+ return (pv_info.features & feature);
+}
+
static inline void load_sp0(struct tss_struct *tss,
struct thread_struct *thread)
{
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 31247b5bff7c..3d44191185f8 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -70,9 +70,14 @@ struct pv_info {
#endif
int paravirt_enabled;
+ unsigned int features; /* valid only if paravirt_enabled is set */
const char *name;
};
+#define paravirt_has(x) paravirt_has_feature(PV_SUPPORTED_##x)
+/* Supported features */
+#define PV_SUPPORTED_RTC (1<<0)
+
struct pv_init_ops {
/*
* Patch may replace one of the defined code sequences with
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 67522256c7ff..2d5a50cb61a2 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -472,6 +472,7 @@ static inline unsigned long current_top_of_stack(void)
#else
#define __cpuid native_cpuid
#define paravirt_enabled() 0
+#define paravirt_has(x) 0
static inline void load_sp0(struct tss_struct *tss,
struct thread_struct *thread)
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index cd9685235df9..4af8d063fb36 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -200,6 +200,9 @@ static __init int add_rtc_cmos(void)
}
#endif
+ if (paravirt_enabled() && !paravirt_has(RTC))
+ return -ENODEV;
+
platform_device_register(&rtc_device);
dev_info(&rtc_device.dev,
"registered platform RTC device (no PNP device found)\n");
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index a0d09f6c6533..a43b2eafc466 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -1414,6 +1414,7 @@ __init void lguest_init(void)
pv_info.kernel_rpl = 1;
/* Everyone except Xen runs with this set. */
pv_info.shared_kernel_pmd = 1;
+ pv_info.features = 0;
/*
* We set up all the lguest overrides for sensitive operations. These
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index d315151411e5..b7de78bdc09c 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1192,7 +1192,7 @@ static const struct pv_info xen_info __initconst = {
#ifdef CONFIG_X86_64
.extra_user_64bit_cs = FLAT_USER_CS64,
#endif
-
+ .features = 0,
.name = "Xen",
};
@@ -1535,6 +1535,8 @@ asmlinkage __visible void __init xen_start_kernel(void)
/* Install Xen paravirt ops */
pv_info = xen_info;
+ if (xen_initial_domain())
+ pv_info.features |= PV_SUPPORTED_RTC;
pv_init_ops = xen_init_ops;
pv_apic_ops = xen_apic_ops;
if (!xen_pvh_domain()) {
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