xref: /openbmc/qemu/target/i386/kvm/kvm-cpu.c (revision de3036ac)
1 /*
2  * x86 KVM CPU type initialization
3  *
4  * Copyright 2021 SUSE LLC
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
7  * See the COPYING file in the top-level directory.
8  */
9 
10 #include "qemu/osdep.h"
11 #include "cpu.h"
12 #include "host-cpu.h"
13 #include "kvm-cpu.h"
14 #include "qapi/error.h"
15 #include "sysemu/sysemu.h"
16 #include "hw/boards.h"
17 
18 #include "kvm_i386.h"
19 #include "hw/core/accel-cpu.h"
20 
21 static bool kvm_cpu_realizefn(CPUState *cs, Error **errp)
22 {
23     X86CPU *cpu = X86_CPU(cs);
24     CPUX86State *env = &cpu->env;
25 
26     /*
27      * The realize order is important, since x86_cpu_realize() checks if
28      * nothing else has been set by the user (or by accelerators) in
29      * cpu->ucode_rev and cpu->phys_bits.
30      *
31      * realize order:
32      * kvm_cpu -> host_cpu -> x86_cpu
33      */
34     if (cpu->max_features) {
35         if (enable_cpu_pm && kvm_has_waitpkg()) {
36             env->features[FEAT_7_0_ECX] |= CPUID_7_0_ECX_WAITPKG;
37         }
38         if (cpu->ucode_rev == 0) {
39             cpu->ucode_rev =
40                 kvm_arch_get_supported_msr_feature(kvm_state,
41                                                    MSR_IA32_UCODE_REV);
42         }
43     }
44     return host_cpu_realizefn(cs, errp);
45 }
46 
47 /*
48  * KVM-specific features that are automatically added/removed
49  * from all CPU models when KVM is enabled.
50  *
51  * NOTE: features can be enabled by default only if they were
52  *       already available in the oldest kernel version supported
53  *       by the KVM accelerator (see "OS requirements" section at
54  *       docs/system/target-i386.rst)
55  */
56 static PropValue kvm_default_props[] = {
57     { "kvmclock", "on" },
58     { "kvm-nopiodelay", "on" },
59     { "kvm-asyncpf", "on" },
60     { "kvm-steal-time", "on" },
61     { "kvm-pv-eoi", "on" },
62     { "kvmclock-stable-bit", "on" },
63     { "x2apic", "on" },
64     { "kvm-msi-ext-dest-id", "off" },
65     { "acpi", "off" },
66     { "monitor", "off" },
67     { "svm", "off" },
68     { NULL, NULL },
69 };
70 
71 void x86_cpu_change_kvm_default(const char *prop, const char *value)
72 {
73     PropValue *pv;
74     for (pv = kvm_default_props; pv->prop; pv++) {
75         if (!strcmp(pv->prop, prop)) {
76             pv->value = value;
77             break;
78         }
79     }
80 
81     /*
82      * It is valid to call this function only for properties that
83      * are already present in the kvm_default_props table.
84      */
85     assert(pv->prop);
86 }
87 
88 static bool lmce_supported(void)
89 {
90     uint64_t mce_cap = 0;
91 
92     if (kvm_ioctl(kvm_state, KVM_X86_GET_MCE_CAP_SUPPORTED, &mce_cap) < 0) {
93         return false;
94     }
95     return !!(mce_cap & MCG_LMCE_P);
96 }
97 
98 static void kvm_cpu_max_instance_init(X86CPU *cpu)
99 {
100     CPUX86State *env = &cpu->env;
101     KVMState *s = kvm_state;
102 
103     host_cpu_max_instance_init(cpu);
104 
105     if (lmce_supported()) {
106         object_property_set_bool(OBJECT(cpu), "lmce", true, &error_abort);
107     }
108 
109     env->cpuid_min_level =
110         kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);
111     env->cpuid_min_xlevel =
112         kvm_arch_get_supported_cpuid(s, 0x80000000, 0, R_EAX);
113     env->cpuid_min_xlevel2 =
114         kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX);
115 }
116 
117 static void kvm_cpu_instance_init(CPUState *cs)
118 {
119     X86CPU *cpu = X86_CPU(cs);
120 
121     host_cpu_instance_init(cpu);
122 
123     if (!kvm_irqchip_in_kernel()) {
124         x86_cpu_change_kvm_default("x2apic", "off");
125     } else if (kvm_irqchip_is_split() && kvm_enable_x2apic()) {
126         x86_cpu_change_kvm_default("kvm-msi-ext-dest-id", "on");
127     }
128 
129     /* Special cases not set in the X86CPUDefinition structs: */
130 
131     x86_cpu_apply_props(cpu, kvm_default_props);
132 
133     if (cpu->max_features) {
134         kvm_cpu_max_instance_init(cpu);
135     }
136 }
137 
138 static void kvm_cpu_accel_class_init(ObjectClass *oc, void *data)
139 {
140     AccelCPUClass *acc = ACCEL_CPU_CLASS(oc);
141 
142     acc->cpu_realizefn = kvm_cpu_realizefn;
143     acc->cpu_instance_init = kvm_cpu_instance_init;
144 }
145 static const TypeInfo kvm_cpu_accel_type_info = {
146     .name = ACCEL_CPU_NAME("kvm"),
147 
148     .parent = TYPE_ACCEL_CPU,
149     .class_init = kvm_cpu_accel_class_init,
150     .abstract = true,
151 };
152 static void kvm_cpu_accel_register_types(void)
153 {
154     type_register_static(&kvm_cpu_accel_type_info);
155 }
156 type_init(kvm_cpu_accel_register_types);
157