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/memblock.h>
10 #include <linux/string.h>
11 
12 #include <uapi/linux/psci.h>
13 
14 #include <asm/hypervisor.h>
15 
16 static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };
17 
kvm_init_hyp_services(void)18 void __init kvm_init_hyp_services(void)
19 {
20 	struct arm_smccc_res res;
21 	u32 val[4];
22 
23 	if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC)
24 		return;
25 
26 	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
27 	if (res.a0 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 ||
28 	    res.a1 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 ||
29 	    res.a2 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 ||
30 	    res.a3 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3)
31 		return;
32 
33 	memset(&res, 0, sizeof(res));
34 	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, &res);
35 
36 	val[0] = lower_32_bits(res.a0);
37 	val[1] = lower_32_bits(res.a1);
38 	val[2] = lower_32_bits(res.a2);
39 	val[3] = lower_32_bits(res.a3);
40 
41 	bitmap_from_arr32(__kvm_arm_hyp_services, val, ARM_SMCCC_KVM_NUM_FUNCS);
42 
43 	pr_info("hypervisor services detected (0x%08lx 0x%08lx 0x%08lx 0x%08lx)\n",
44 		 res.a3, res.a2, res.a1, res.a0);
45 
46 	kvm_arch_init_hyp_services();
47 }
48 
kvm_arm_hyp_service_available(u32 func_id)49 bool kvm_arm_hyp_service_available(u32 func_id)
50 {
51 	if (func_id >= ARM_SMCCC_KVM_NUM_FUNCS)
52 		return false;
53 
54 	return test_bit(func_id, __kvm_arm_hyp_services);
55 }
56 EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);
57 
58 #ifdef CONFIG_ARM64
kvm_arm_target_impl_cpu_init(void)59 void  __init kvm_arm_target_impl_cpu_init(void)
60 {
61 	int i;
62 	u32 ver;
63 	u64 max_cpus;
64 	struct arm_smccc_res res;
65 	struct target_impl_cpu *target;
66 
67 	if (!kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_VER) ||
68 	    !kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_CPUS))
69 		return;
70 
71 	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_VER_FUNC_ID,
72 			     0, &res);
73 	if (res.a0 != SMCCC_RET_SUCCESS)
74 		return;
75 
76 	/* Version info is in lower 32 bits and is in SMMCCC_VERSION format */
77 	ver = lower_32_bits(res.a1);
78 	if (PSCI_VERSION_MAJOR(ver) != 1) {
79 		pr_warn("Unsupported target CPU implementation version v%d.%d\n",
80 			PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));
81 		return;
82 	}
83 
84 	if (!res.a2) {
85 		pr_warn("No target implementation CPUs specified\n");
86 		return;
87 	}
88 
89 	max_cpus = res.a2;
90 	target = memblock_alloc(sizeof(*target) * max_cpus,  __alignof__(*target));
91 	if (!target) {
92 		pr_warn("Not enough memory for struct target_impl_cpu\n");
93 		return;
94 	}
95 
96 	for (i = 0; i < max_cpus; i++) {
97 		arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID,
98 				     i, 0, 0, &res);
99 		if (res.a0 != SMCCC_RET_SUCCESS) {
100 			pr_warn("Discovering target implementation CPUs failed\n");
101 			goto mem_free;
102 		}
103 		target[i].midr = res.a1;
104 		target[i].revidr = res.a2;
105 		target[i].aidr = res.a3;
106 	}
107 
108 	if (!cpu_errata_set_target_impl(max_cpus, target)) {
109 		pr_warn("Failed to set target implementation CPUs\n");
110 		goto mem_free;
111 	}
112 
113 	pr_info("Number of target implementation CPUs is %lld\n", max_cpus);
114 	return;
115 
116 mem_free:
117 	memblock_free(target, sizeof(*target) * max_cpus);
118 }
119 #endif
120