/* Basic PCID & INVPCID functionality test */ #include "libcflat.h" #include "processor.h" #include "desc.h" #define X86_FEATURE_PCID (1 << 17) #define X86_FEATURE_INVPCID (1 << 10) struct invpcid_desc { unsigned long pcid : 12; unsigned long rsv : 52; unsigned long addr : 64; }; int write_cr0_checking(unsigned long val) { asm volatile(ASM_TRY("1f") "mov %0, %%cr0\n\t" "1:": : "r" (val)); return exception_vector(); } int write_cr4_checking(unsigned long val) { asm volatile(ASM_TRY("1f") "mov %0, %%cr4\n\t" "1:": : "r" (val)); return exception_vector(); } int invpcid_checking(unsigned long type, void *desc) { asm volatile (ASM_TRY("1f") ".byte 0x66,0x0f,0x38,0x82,0x18 \n\t" /* invpcid (%rax), %rbx */ "1:" : : "a" (desc), "b" (type)); return exception_vector(); } void test_cpuid_consistency(int pcid_enabled, int invpcid_enabled) { int passed = !(!pcid_enabled && invpcid_enabled); report("CPUID consistency", passed); } void test_pcid_enabled(void) { int passed = 0; ulong cr0 = read_cr0(), cr3 = read_cr3(), cr4 = read_cr4(); /* try setting CR4.PCIDE, no exception expected */ if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != 0) goto report; /* try clearing CR0.PG when CR4.PCIDE=1, #GP expected */ if (write_cr0_checking(cr0 & ~X86_CR0_PG) != GP_VECTOR) goto report; write_cr4(cr4); /* try setting CR4.PCIDE when CR3[11:0] != 0 , #GP expected */ write_cr3(cr3 | 0x001); if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != GP_VECTOR) goto report; write_cr3(cr3); passed = 1; report: report("Test on PCID when enabled", passed); } void test_pcid_disabled(void) { int passed = 0; ulong cr4 = read_cr4(); /* try setting CR4.PCIDE, #GP expected */ if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != GP_VECTOR) goto report; passed = 1; report: report("Test on PCID when disabled", passed); } void test_invpcid_enabled(void) { int passed = 0; ulong cr4 = read_cr4(); struct invpcid_desc desc; desc.rsv = 0; /* try executing invpcid when CR4.PCIDE=0, desc.pcid=0 and type=1 * no exception expected */ desc.pcid = 0; if (invpcid_checking(1, &desc) != 0) goto report; /* try executing invpcid when CR4.PCIDE=0, desc.pcid=1 and type=1 * #GP expected */ desc.pcid = 1; if (invpcid_checking(1, &desc) != GP_VECTOR) goto report; if (write_cr4_checking(cr4 | X86_CR4_PCIDE) != 0) goto report; /* try executing invpcid when CR4.PCIDE=1 * no exception expected */ desc.pcid = 10; if (invpcid_checking(2, &desc) != 0) goto report; passed = 1; report: report("Test on INVPCID when enabled", passed); } void test_invpcid_disabled(void) { int passed = 0; struct invpcid_desc desc; /* try executing invpcid, #UD expected */ if (invpcid_checking(2, &desc) != UD_VECTOR) goto report; passed = 1; report: report("Test on INVPCID when disabled", passed); } int main(int ac, char **av) { struct cpuid _cpuid; int pcid_enabled = 0, invpcid_enabled = 0; setup_idt(); _cpuid = cpuid(1); if (_cpuid.c & X86_FEATURE_PCID) pcid_enabled = 1; _cpuid = cpuid_indexed(7, 0); if (_cpuid.b & X86_FEATURE_INVPCID) invpcid_enabled = 1; test_cpuid_consistency(pcid_enabled, invpcid_enabled); if (pcid_enabled) test_pcid_enabled(); else test_pcid_disabled(); if (invpcid_enabled) test_invpcid_enabled(); else test_invpcid_disabled(); return report_summary(); }