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
kvm_arm_init_hyp_services(void)12 void __weak kvm_arm_init_hyp_services(void) {}
13
14 static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };
15
kvm_init_hyp_services(void)16 void __init kvm_init_hyp_services(void)
17 {
18 struct arm_smccc_res res;
19 u32 val[4];
20
21 if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC)
22 return;
23
24 arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
25 if (res.a0 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 ||
26 res.a1 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 ||
27 res.a2 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 ||
28 res.a3 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3)
29 return;
30
31 memset(&res, 0, sizeof(res));
32 arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, &res);
33
34 val[0] = lower_32_bits(res.a0);
35 val[1] = lower_32_bits(res.a1);
36 val[2] = lower_32_bits(res.a2);
37 val[3] = lower_32_bits(res.a3);
38
39 bitmap_from_arr32(__kvm_arm_hyp_services, val, ARM_SMCCC_KVM_NUM_FUNCS);
40
41 pr_info("hypervisor services detected (0x%08lx 0x%08lx 0x%08lx 0x%08lx)\n",
42 res.a3, res.a2, res.a1, res.a0);
43
44 kvm_arm_init_hyp_services();
45 }
46
kvm_arm_hyp_service_available(u32 func_id)47 bool kvm_arm_hyp_service_available(u32 func_id)
48 {
49 if (func_id >= ARM_SMCCC_KVM_NUM_FUNCS)
50 return false;
51
52 return test_bit(func_id, __kvm_arm_hyp_services);
53 }
54 EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);
55