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/cache.h>
 8#include <linux/kernel.h>
 9#include <linux/string.h>
10
11#include <asm/hypervisor.h>
12
13static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };
14
15void __init kvm_init_hyp_services(void)
16{
17	struct arm_smccc_res res;
18	u32 val[4];
19
20	if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC)
21		return;
22
23	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
24	if (res.a0 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 ||
25	    res.a1 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 ||
26	    res.a2 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 ||
27	    res.a3 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3)
28		return;
29
30	memset(&res, 0, sizeof(res));
31	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, &res);
32
33	val[0] = lower_32_bits(res.a0);
34	val[1] = lower_32_bits(res.a1);
35	val[2] = lower_32_bits(res.a2);
36	val[3] = lower_32_bits(res.a3);
37
38	bitmap_from_arr32(__kvm_arm_hyp_services, val, ARM_SMCCC_KVM_NUM_FUNCS);
39
40	pr_info("hypervisor services detected (0x%08lx 0x%08lx 0x%08lx 0x%08lx)\n",
41		 res.a3, res.a2, res.a1, res.a0);
42}
43
44bool kvm_arm_hyp_service_available(u32 func_id)
45{
46	if (func_id >= ARM_SMCCC_KVM_NUM_FUNCS)
47		return false;
48
49	return test_bit(func_id, __kvm_arm_hyp_services);
50}
51EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);