xref: /kvm-unit-tests/x86/pcid.c (revision a1a39c97b64c3c91970830e9409ec7ac2fcc222c)
1 /* Basic PCID & INVPCID functionality test */
2 
3 #include "libcflat.h"
4 #include "processor.h"
5 #include "desc.h"
6 
7 #define X86_FEATURE_PCID       (1 << 17)
8 #define X86_FEATURE_INVPCID    (1 << 10)
9 
10 struct invpcid_desc {
11     unsigned long pcid : 12;
12     unsigned long rsv  : 52;
13     unsigned long addr : 64;
14 };
15 
16 int write_cr0_checking(unsigned long val)
17 {
18     asm volatile(ASM_TRY("1f")
19                  "mov %0, %%cr0\n\t"
20                  "1:": : "r" (val));
21     return exception_vector();
22 }
23 
24 int write_cr4_checking(unsigned long val)
25 {
26     asm volatile(ASM_TRY("1f")
27                  "mov %0, %%cr4\n\t"
28                  "1:": : "r" (val));
29     return exception_vector();
30 }
31 
32 int invpcid_checking(unsigned long type, void *desc)
33 {
34     asm volatile (ASM_TRY("1f")
35                   ".byte 0x66,0x0f,0x38,0x82,0x18 \n\t" /* invpcid (%rax), %rbx */
36                   "1:" : : "a" (desc), "b" (type));
37     return exception_vector();
38 }
39 
40 void test_cpuid_consistency(int pcid_enabled, int invpcid_enabled)
41 {
42     int passed = !(!pcid_enabled && invpcid_enabled);
43     report("CPUID consistency", passed);
44 }
45 
46 void test_pcid_enabled(void)
47 {
48     int passed = 0;
49     ulong cr0 = read_cr0(), cr3 = read_cr3(), cr4 = read_cr4();
50 
51     /* try setting CR4.PCIDE, no exception expected */
52     if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != 0)
53         goto report;
54 
55     /* try clearing CR0.PG when CR4.PCIDE=1, #GP expected */
56     if (write_cr0_checking(cr0 & ~X86_CR0_PG) != GP_VECTOR)
57         goto report;
58 
59     write_cr4(cr4);
60 
61     /* try setting CR4.PCIDE when CR3[11:0] != 0 , #GP expected */
62     write_cr3(cr3 | 0x001);
63     if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != GP_VECTOR)
64         goto report;
65     write_cr3(cr3);
66 
67     passed = 1;
68 
69 report:
70     report("Test on PCID when enabled", passed);
71 }
72 
73 void test_pcid_disabled(void)
74 {
75     int passed = 0;
76     ulong cr4 = read_cr4();
77 
78     /* try setting CR4.PCIDE, #GP expected */
79     if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != GP_VECTOR)
80         goto report;
81 
82     passed = 1;
83 
84 report:
85     report("Test on PCID when disabled", passed);
86 }
87 
88 void test_invpcid_enabled(void)
89 {
90     int passed = 0;
91     ulong cr4 = read_cr4();
92     struct invpcid_desc desc;
93     desc.rsv = 0;
94 
95     /* try executing invpcid when CR4.PCIDE=0, desc.pcid=0 and type=1
96      * no exception expected
97      */
98     desc.pcid = 0;
99     if (invpcid_checking(1, &desc) != 0)
100         goto report;
101 
102     /* try executing invpcid when CR4.PCIDE=0, desc.pcid=1 and type=1
103      * #GP expected
104      */
105     desc.pcid = 1;
106     if (invpcid_checking(1, &desc) != GP_VECTOR)
107         goto report;
108 
109     if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != 0)
110         goto report;
111 
112     /* try executing invpcid when CR4.PCIDE=1
113      * no exception expected
114      */
115     desc.pcid = 10;
116     if (invpcid_checking(2, &desc) != 0)
117         goto report;
118 
119     passed = 1;
120 
121 report:
122     report("Test on INVPCID when enabled", passed);
123 }
124 
125 void test_invpcid_disabled(void)
126 {
127     int passed = 0;
128     struct invpcid_desc desc;
129 
130     /* try executing invpcid, #UD expected */
131     if (invpcid_checking(2, &desc) != UD_VECTOR)
132         goto report;
133 
134     passed = 1;
135 
136 report:
137     report("Test on INVPCID when disabled", passed);
138 }
139 
140 int main(int ac, char **av)
141 {
142     struct cpuid _cpuid;
143     int pcid_enabled = 0, invpcid_enabled = 0;
144 
145     setup_idt();
146 
147     _cpuid = cpuid(1);
148     if (_cpuid.c & X86_FEATURE_PCID)
149         pcid_enabled = 1;
150     _cpuid = cpuid_indexed(7, 0);
151     if (_cpuid.b & X86_FEATURE_INVPCID)
152         invpcid_enabled = 1;
153 
154     test_cpuid_consistency(pcid_enabled, invpcid_enabled);
155 
156     if (pcid_enabled)
157         test_pcid_enabled();
158     else
159         test_pcid_disabled();
160 
161     if (invpcid_enabled)
162         test_invpcid_enabled();
163     else
164         test_invpcid_disabled();
165 
166     return report_summary();
167 }
168