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Diffstat (limited to 'drivers/firmware/smccc/kvm_guest.c')
-rw-r--r--drivers/firmware/smccc/kvm_guest.c51
1 files changed, 51 insertions, 0 deletions
diff --git a/drivers/firmware/smccc/kvm_guest.c b/drivers/firmware/smccc/kvm_guest.c
new file mode 100644
index 000000000..89a68e7ee
--- /dev/null
+++ b/drivers/firmware/smccc/kvm_guest.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "smccc: KVM: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/bitmap.h>
+#include <linux/cache.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);