kvm/test/x86/vmexit.c

   1
   2 #include "libcflat.h"
   3 #include "smp.h"
   4
   5 static inline unsigned long long rdtsc()
   6 {
   7         long long r;
   8
   9 #ifdef __x86_64__
  10         unsigned a, d;
  11
  12         asm volatile ("rdtsc" : "=a"(a), "=d"(d));
  13         r = a | ((long long)d << 32);
  14 #else
  15         asm volatile ("rdtsc" : "=A"(r));
  16 #endif
  17         return r;
  18 }
  19
  20 static unsigned int inl(unsigned short port)
  21 {
  22     unsigned int val;
  23     asm volatile("inl %w1, %0" : "=a"(val) : "Nd"(port));
  24     return val;
  25 }
  26
  27 #define GOAL (1ull << 30)
  28
  29 #ifdef __x86_64__
  30 #  define R "r"
  31 #else
  32 #  define R "e"
  33 #endif
  34
  35 static void cpuid(void)
  36 {
  37         asm volatile ("push %%"R "bx; cpuid; pop %%"R "bx"
  38                       : : : "eax", "ecx", "edx");
  39 }
  40
  41 static void vmcall(void)
  42 {
  43         unsigned long a = 0, b, c, d;
  44
  45         asm volatile ("vmcall" : "+a"(a), "=b"(b), "=c"(c), "=d"(d));
  46 }
  47
  48 #define MSR_EFER 0xc0000080
  49 #define EFER_NX_MASK            (1ull << 11)
  50
  51 unsigned long long rdmsr(unsigned index)
  52 {
  53         unsigned a, d;
  54
  55         asm volatile("rdmsr" : "=a"(a), "=d"(d) : "c"(index));
  56         return ((unsigned long long)d << 32) | a;
  57 }
  58
  59 void wrmsr(unsigned index, unsigned long long val)
  60 {
  61         unsigned a = val, d = val >> 32;
  62
  63         asm volatile("wrmsr" : : "a"(a), "d"(d), "c"(index));
  64 }
  65
  66 static void mov_from_cr8(void)
  67 {
  68         unsigned long cr8;
  69
  70         asm volatile ("mov %%cr8, %0" : "=r"(cr8));
  71 }
  72
  73 static void mov_to_cr8(void)
  74 {
  75         unsigned long cr8 = 0;
  76
  77         asm volatile ("mov %0, %%cr8" : : "r"(cr8));
  78 }
  79
  80 static int is_smp(void)
  81 {
  82         return cpu_count() > 1;
  83 }
  84
  85 static void nop(void *junk)
  86 {
  87 }
  88
  89 static void ipi(void)
  90 {
  91         on_cpu(1, nop, 0);
  92 }
  93
  94 static void ipi_halt(void)
  95 {
  96         unsigned long long t;
  97
  98         on_cpu(1, nop, 0);
  99         t = rdtsc() + 2000;
 100         while (rdtsc() < t)
 101                 ;
 102 }
 103
 104 static void inl_pmtimer(void)
 105 {
 106     inl(0xb008);
 107 }
 108
 109 static struct test {
 110         void (*func)(void);
 111         const char *name;
 112         int (*valid)(void);
 113         int parallel;
 114 } tests[] = {
 115         { cpuid, "cpuid", .parallel = 1,  },
 116         { vmcall, "vmcall", .parallel = 1, },
 117         { mov_from_cr8, "mov_from_cr8", .parallel = 1, },
 118         { mov_to_cr8, "mov_to_cr8" , .parallel = 1, },
 119         { inl_pmtimer, "inl_from_pmtimer", .parallel = 1, },
 120         { ipi, "ipi", is_smp, .parallel = 0, },
 121         { ipi_halt, "ipi+halt", is_smp, .parallel = 0, },
 122 };
 123
 124 unsigned iterations;
 125 volatile int nr_cpus_done;
 126
 127 static void run_test(void *_func)
 128 {
 129     int i;
 130     void (*func)(void) = _func;
 131
 132     for (i = 0; i < iterations; ++i)
 133         func();
 134
 135     nr_cpus_done++;
 136 }
 137
 138 static void do_test(struct test *test)
 139 {
 140         int i;
 141         unsigned long long t1, t2;
 142         void (*func)(void) = test->func;
 143
 144         iterations = 32;
 145
 146         if (test->valid && !test->valid()) {
 147                 printf("%s (skipped)\n", test->name);
 148                 return;
 149         }
 150
 151         do {
 152                 iterations *= 2;
 153                 t1 = rdtsc();
 154
 155                 if (!test->parallel) {
 156                         for (i = 0; i < iterations; ++i)
 157                                 func();
 158                 } else {
 159                         nr_cpus_done = 0;
 160                         for (i = cpu_count(); i > 0; i--)
 161                                 on_cpu_async(i-1, run_test, func);
 162                         while (nr_cpus_done < cpu_count())
 163                                 ;
 164                 }
 165                 t2 = rdtsc();
 166         } while ((t2 - t1) < GOAL);
 167         printf("%s %d\n", test->name, (int)((t2 - t1) / iterations));
 168 }
 169
 170 static void enable_nx(void *junk)
 171 {
 172         wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_NX_MASK);
 173 }
 174
 175 int main(void)
 176 {
 177         int i;
 178
 179         smp_init();
 180
 181         for (i = cpu_count(); i > 0; i--)
 182                 on_cpu(i-1, enable_nx, 0);
 183
 184         for (i = 0; i < ARRAY_SIZE(tests); ++i)
 185                 do_test(&tests[i]);
 186
 187         return 0;
 188 }