Merge tag 'x86-paravirt-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-microblaze.git] / arch / arm64 / kvm / hypercalls.c
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2019 Arm Ltd.
3
4 #include <linux/arm-smccc.h>
5 #include <linux/kvm_host.h>
6
7 #include <asm/kvm_emulate.h>
8
9 #include <kvm/arm_hypercalls.h>
10 #include <kvm/arm_psci.h>
11
12 int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
13 {
14         u32 func_id = smccc_get_function(vcpu);
15         long val = SMCCC_RET_NOT_SUPPORTED;
16         u32 feature;
17         gpa_t gpa;
18
19         switch (func_id) {
20         case ARM_SMCCC_VERSION_FUNC_ID:
21                 val = ARM_SMCCC_VERSION_1_1;
22                 break;
23         case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
24                 feature = smccc_get_arg1(vcpu);
25                 switch (feature) {
26                 case ARM_SMCCC_ARCH_WORKAROUND_1:
27                         switch (arm64_get_spectre_v2_state()) {
28                         case SPECTRE_VULNERABLE:
29                                 break;
30                         case SPECTRE_MITIGATED:
31                                 val = SMCCC_RET_SUCCESS;
32                                 break;
33                         case SPECTRE_UNAFFECTED:
34                                 val = SMCCC_RET_NOT_REQUIRED;
35                                 break;
36                         }
37                         break;
38                 case ARM_SMCCC_ARCH_WORKAROUND_2:
39                         switch (arm64_get_spectre_v4_state()) {
40                         case SPECTRE_VULNERABLE:
41                                 break;
42                         case SPECTRE_MITIGATED:
43                                 /*
44                                  * SSBS everywhere: Indicate no firmware
45                                  * support, as the SSBS support will be
46                                  * indicated to the guest and the default is
47                                  * safe.
48                                  *
49                                  * Otherwise, expose a permanent mitigation
50                                  * to the guest, and hide SSBS so that the
51                                  * guest stays protected.
52                                  */
53                                 if (cpus_have_final_cap(ARM64_SSBS))
54                                         break;
55                                 fallthrough;
56                         case SPECTRE_UNAFFECTED:
57                                 val = SMCCC_RET_NOT_REQUIRED;
58                                 break;
59                         }
60                         break;
61                 case ARM_SMCCC_HV_PV_TIME_FEATURES:
62                         val = SMCCC_RET_SUCCESS;
63                         break;
64                 }
65                 break;
66         case ARM_SMCCC_HV_PV_TIME_FEATURES:
67                 val = kvm_hypercall_pv_features(vcpu);
68                 break;
69         case ARM_SMCCC_HV_PV_TIME_ST:
70                 gpa = kvm_init_stolen_time(vcpu);
71                 if (gpa != GPA_INVALID)
72                         val = gpa;
73                 break;
74         default:
75                 return kvm_psci_call(vcpu);
76         }
77
78         smccc_set_retval(vcpu, val, 0, 0, 0);
79         return 1;
80 }