xref: /kvm-unit-tests/x86/pcid.c (revision f1dcfd54130ca2b1851d46dffd7ffadbe5eb4a3b)
1 /* Basic PCID & INVPCID functionality test */
2 
3 #include "libcflat.h"
4 #include "processor.h"
5 #include "desc.h"
6 
7 struct invpcid_desc {
8     u64 pcid : 12;
9     u64 rsv  : 52;
10     u64 addr : 64;
11 };
12 
13 static int write_cr0_checking(unsigned long val)
14 {
15     asm volatile(ASM_TRY("1f")
16                  "mov %0, %%cr0\n\t"
17                  "1:": : "r" (val));
18     return exception_vector();
19 }
20 
21 static int invpcid_checking(unsigned long type, void *desc)
22 {
23     asm volatile (ASM_TRY("1f")
24                   ".byte 0x66,0x0f,0x38,0x82,0x18 \n\t" /* invpcid (%rax), %rbx */
25                   "1:" : : "a" (desc), "b" (type));
26     return exception_vector();
27 }
28 
29 static void test_pcid_enabled(void)
30 {
31     int passed = 0;
32     ulong cr0 = read_cr0(), cr3 = read_cr3(), cr4 = read_cr4();
33 
34     /* try setting CR4.PCIDE, no exception expected */
35     if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != 0)
36         goto report;
37 
38     /* try clearing CR0.PG when CR4.PCIDE=1, #GP expected */
39     if (write_cr0_checking(cr0 & ~X86_CR0_PG) != GP_VECTOR)
40         goto report;
41 
42     write_cr4(cr4);
43 
44     /* try setting CR4.PCIDE when CR3[11:0] != 0 , #GP expected */
45     write_cr3(cr3 | 0x001);
46     if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != GP_VECTOR)
47         goto report;
48     write_cr3(cr3);
49 
50     passed = 1;
51 
52 report:
53     report(passed, "Test on PCID when enabled");
54 }
55 
56 static void test_pcid_disabled(void)
57 {
58     int passed = 0;
59     ulong cr4 = read_cr4();
60 
61     /* try setting CR4.PCIDE, #GP expected */
62     if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != GP_VECTOR)
63         goto report;
64 
65     passed = 1;
66 
67 report:
68     report(passed, "Test on PCID when disabled");
69 }
70 
71 static void test_invpcid_enabled(int pcid_enabled)
72 {
73     int passed = 0, i;
74     ulong cr4 = read_cr4();
75     struct invpcid_desc desc;
76 
77     memset(&desc, 0, sizeof(desc));
78 
79     /* try executing invpcid when CR4.PCIDE=0, desc.pcid=0 and type=0..3
80      * no exception expected
81      */
82     for (i = 0; i < 4; i++) {
83         if (invpcid_checking(i, &desc) != 0)
84             goto report;
85     }
86 
87     /* try executing invpcid when CR4.PCIDE=0, desc.pcid=1 and type=0..1
88      * #GP expected
89      */
90     desc.pcid = 1;
91     for (i = 0; i < 2; i++) {
92         if (invpcid_checking(i, &desc) != GP_VECTOR)
93             goto report;
94     }
95 
96     /* Skip tests that require the PCIDE=1 if PCID isn't supported. */
97     if (!pcid_enabled)
98         goto success;
99 
100     if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != 0)
101         goto report;
102 
103     /* try executing invpcid when CR4.PCIDE=1
104      * no exception expected
105      */
106     desc.pcid = 10;
107     if (invpcid_checking(2, &desc) != 0)
108         goto report;
109 
110 success:
111     passed = 1;
112 
113 report:
114     report(passed, "Test on INVPCID when enabled");
115 }
116 
117 static void test_invpcid_disabled(void)
118 {
119     int passed = 0;
120     struct invpcid_desc desc;
121 
122     /* try executing invpcid, #UD expected */
123     if (invpcid_checking(2, &desc) != UD_VECTOR)
124         goto report;
125 
126     passed = 1;
127 
128 report:
129     report(passed, "Test on INVPCID when disabled");
130 }
131 
132 int main(int ac, char **av)
133 {
134     int pcid_enabled = 0, invpcid_enabled = 0;
135 
136     if (this_cpu_has(X86_FEATURE_PCID))
137         pcid_enabled = 1;
138     if (this_cpu_has(X86_FEATURE_INVPCID))
139         invpcid_enabled = 1;
140 
141     if (pcid_enabled)
142         test_pcid_enabled();
143     else
144         test_pcid_disabled();
145 
146     if (invpcid_enabled)
147         test_invpcid_enabled(pcid_enabled);
148     else
149         test_invpcid_disabled();
150 
151     return report_summary();
152 }
153