Il 15/07/2014 16:41, Nadav Amit ha scritto: > Recently discovered bug shows DR6.RTM is fixed to one. The bug is only > apparent > when the host emulates the MOV-DR instruction or when the host debugs the > guest kernel. This patch tests whether DR6.RTM is indeed accessible according > to RTM support as reported by cpuid. > > Signed-off-by: Nadav Amit <[email protected]> > --- > x86/emulator.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/x86/emulator.c b/x86/emulator.c > index 1fd0ca6..f68882f 100644 > --- a/x86/emulator.c > +++ b/x86/emulator.c > @@ -3,6 +3,7 @@ > #include "libcflat.h" > #include "desc.h" > #include "types.h" > +#include "processor.h" > > #define memset __builtin_memset > #define TESTDEV_IO_PORT 0xe0 > @@ -870,6 +871,19 @@ static void test_nop(uint64_t *mem, uint8_t *insn_page, > report("nop", outregs.rax == inregs.rax); > } > > +static void test_mov_dr(uint64_t *mem, uint8_t *insn_page, > + uint8_t *alt_insn_page, void *insn_ram) > +{ > + bool rtm_support = cpuid(7).b & (1 << 11); > + unsigned long dr6_fixed_1 = rtm_support ? 0xfffe0ff0ul : 0xffff0ff0ul; > + inregs = (struct regs){ .rax = 0 }; > + MK_INSN(mov_to_dr6, "movq %rax, %dr6\n\t"); > + trap_emulator(mem, alt_insn_page, &insn_mov_to_dr6); > + MK_INSN(mov_from_dr6, "movq %dr6, %rax\n\t"); > + trap_emulator(mem, alt_insn_page, &insn_mov_from_dr6); > + report("mov_dr6", outregs.rax == dr6_fixed_1); > +} > + > static void test_crosspage_mmio(volatile uint8_t *mem) > { > volatile uint16_t w, *pw; > @@ -1072,6 +1086,7 @@ int main() > test_movabs(mem, insn_page, alt_insn_page, insn_ram); > test_smsw_reg(mem, insn_page, alt_insn_page, insn_ram); > test_nop(mem, insn_page, alt_insn_page, insn_ram); > + test_mov_dr(mem, insn_page, alt_insn_page, insn_ram); > test_crosspage_mmio(mem); > > test_string_io_mmio(mem); >
Thanks, applying. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
