1// SPDX-License-Identifier: GPL-2.0
 2
 3#define pr_fmt(fmt) "smccc: KVM: " fmt
 4
 5#include <linux/arm-smccc.h>
 6#include <linux/bitmap.h>
 7#include <linux/kernel.h>
 8#include <linux/string.h>
 9
10#include <asm/hypervisor.h>
11
12static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };
13
14void __init kvm_init_hyp_services(void)
15{
16	struct arm_smccc_res res;
17	u32 val[4];
18
19	if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC)
20		return;
21
22	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
23	if (res.a0 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 ||
24	    res.a1 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 ||
25	    res.a2 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 ||
26	    res.a3 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3)
27		return;
28
29	memset(&res, 0, sizeof(res));
30	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, &res);
31
32	val[0] = lower_32_bits(res.a0);
33	val[1] = lower_32_bits(res.a1);
34	val[2] = lower_32_bits(res.a2);
35	val[3] = lower_32_bits(res.a3);
36
37	bitmap_from_arr32(__kvm_arm_hyp_services, val, ARM_SMCCC_KVM_NUM_FUNCS);
38
39	pr_info("hypervisor services detected (0x%08lx 0x%08lx 0x%08lx 0x%08lx)\n",
40		 res.a3, res.a2, res.a1, res.a0);
41}
42
43bool kvm_arm_hyp_service_available(u32 func_id)
44{
45	if (func_id >= ARM_SMCCC_KVM_NUM_FUNCS)
46		return false;
47
48	return test_bit(func_id, __kvm_arm_hyp_services);
49}
50EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);