Add multibyte NOP test case to kvm-unit-tests. This case can test one of bugs when booting RHEL5.9 64-bit. Signed-off-by: Arthur Chunqi Li <yzt356@xxxxxxxxx> --- x86/emulator.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/x86/emulator.c b/x86/emulator.c index 96576e5..f26c70f 100644 --- a/x86/emulator.c +++ b/x86/emulator.c @@ -901,6 +901,37 @@ static void test_simplealu(u32 *mem) report("test", *mem == 0x8400); } +static void test_nopl(uint64_t *mem, uint8_t *insn_page, + uint8_t *alt_insn_page, void *insn_ram) +{ + ulong *cr3 = (ulong *)read_cr3(); + + // Pad with RET instructions + memset(insn_page, 0xc3, 4096); + memset(alt_insn_page, 0xc3, 4096); + // Place a trapping instruction in the page to trigger a VMEXIT + insn_page[0] = 0x89; // mov %eax, (%rax) + insn_page[1] = 0x00; + insn_page[2] = 0x90; // nop + // Place nopl 0x0(%eax) in alt_insn_page for emulator to execuate + alt_insn_page[0] = 0x0f; // nop DWORD ptr[EAX] + alt_insn_page[1] = 0x1f; + alt_insn_page[2] = 0x00; + + // Load the code TLB with insn_page, but point the page tables at + // alt_insn_page (and keep the data TLB clear, for AMD decode assist). + // This will make the CPU trap on the insn_page instruction but the + // hypervisor will see alt_insn_page. + install_page(cr3, virt_to_phys(insn_page), insn_ram); + // Load code TLB + invlpg(insn_ram); + asm volatile("call *%0" : : "r"(insn_ram + 3)); + // Trap, let hypervisor emulate at alt_insn_page + install_page(cr3, virt_to_phys(alt_insn_page), insn_ram); + asm volatile("call *%0" : : "r"(insn_ram), "a"(mem)); + report("nopl", 1); +} + int main() { void *mem; @@ -964,6 +995,8 @@ int main() test_string_io_mmio(mem); + test_nopl(mem, insn_page, alt_insn_page, insn_ram); + printf("\nSUMMARY: %d tests, %d failures\n", tests, fails); return fails ? 1 : 0; } -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html