4 files changed, 54 insertions, 1 deletions
diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index f5fc429cae3f..69e296f02902 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -23,6 +23,7 @@
 
 #include <asm/cpuidle.h>
 #include <asm/cputype.h>
+#include <asm/hypervisor.h>
 #include <asm/system_misc.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
@@ -498,6 +499,7 @@ static int __init psci_probe(void)
 		psci_init_cpu_suspend();
 		psci_init_system_suspend();
 		psci_init_system_reset2();
+		kvm_init_hyp_services();
 	}
 
 	return 0;
diff --git a/drivers/firmware/smccc/Makefile b/drivers/firmware/smccc/Makefile
index 72ab84042832..40d19144a860 100644
--- a/drivers/firmware/smccc/Makefile
+++ b/drivers/firmware/smccc/Makefile
@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 #
-obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY)	+= smccc.o
+obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY)	+= smccc.o kvm_guest.o
 obj-$(CONFIG_ARM_SMCCC_SOC_ID)	+= soc_id.o
diff --git a/drivers/firmware/smccc/kvm_guest.c b/drivers/firmware/smccc/kvm_guest.c
new file mode 100644
index 000000000000..2d3e866decaa
--- /dev/null
+++ b/drivers/firmware/smccc/kvm_guest.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "smccc: KVM: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/bitmap.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+
+#include <asm/hypervisor.h>
+
+static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };
+
+void __init kvm_init_hyp_services(void)
+{
+	struct arm_smccc_res res;
+	u32 val[4];
+
+	if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC)
+		return;
+
+	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
+	if (res.a0 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 ||
+	    res.a1 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 ||
+	    res.a2 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 ||
+	    res.a3 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3)
+		return;
+
+	memset(&res, 0, sizeof(res));
+	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, &res);
+
+	val[0] = lower_32_bits(res.a0);
+	val[1] = lower_32_bits(res.a1);
+	val[2] = lower_32_bits(res.a2);
+	val[3] = lower_32_bits(res.a3);
+
+	bitmap_from_arr32(__kvm_arm_hyp_services, val, ARM_SMCCC_KVM_NUM_FUNCS);
+
+	pr_info("hypervisor services detected (0x%08lx 0x%08lx 0x%08lx 0x%08lx)\n",
+		 res.a3, res.a2, res.a1, res.a0);
+}
+
+bool kvm_arm_hyp_service_available(u32 func_id)
+{
+	if (func_id >= ARM_SMCCC_KVM_NUM_FUNCS)
+		return false;
+
+	return test_bit(func_id, __kvm_arm_hyp_services);
+}
+EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);
diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c
index d52bfc5ed5e4..028f81d702cc 100644
--- a/drivers/firmware/smccc/smccc.c
+++ b/drivers/firmware/smccc/smccc.c
@@ -8,6 +8,7 @@
 #include <linux/cache.h>
 #include <linux/init.h>
 #include <linux/arm-smccc.h>
+#include <linux/kernel.h>
 #include <asm/archrandom.h>
 
 static u32 smccc_version = ARM_SMCCC_VERSION_1_0;