diff options
Diffstat (limited to 'target/i386/tcg/sysemu/seg_helper.c')
| -rw-r--r-- | target/i386/tcg/sysemu/seg_helper.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/target/i386/tcg/sysemu/seg_helper.c b/target/i386/tcg/sysemu/seg_helper.c index e0d7b32b82..82c0856c41 100644 --- a/target/i386/tcg/sysemu/seg_helper.c +++ b/target/i386/tcg/sysemu/seg_helper.c @@ -23,6 +23,7 @@ #include "exec/helper-proto.h" #include "exec/cpu_ldst.h" #include "tcg/helper-tcg.h" +#include "../seg_helper.h" #ifdef TARGET_X86_64 void helper_syscall(CPUX86State *env, int next_eip_addend) @@ -123,3 +124,31 @@ void x86_cpu_do_interrupt(CPUState *cs) env->old_exception = -1; } } + +/* check if Port I/O is allowed in TSS */ +void helper_check_io(CPUX86State *env, uint32_t addr, uint32_t size) +{ + uintptr_t retaddr = GETPC(); + uint32_t io_offset, val, mask; + + /* TSS must be a valid 32 bit one */ + if (!(env->tr.flags & DESC_P_MASK) || + ((env->tr.flags >> DESC_TYPE_SHIFT) & 0xf) != 9 || + env->tr.limit < 103) { + goto fail; + } + io_offset = cpu_lduw_kernel_ra(env, env->tr.base + 0x66, retaddr); + io_offset += (addr >> 3); + /* Note: the check needs two bytes */ + if ((io_offset + 1) > env->tr.limit) { + goto fail; + } + val = cpu_lduw_kernel_ra(env, env->tr.base + io_offset, retaddr); + val >>= (addr & 7); + mask = (1 << size) - 1; + /* all bits must be zero to allow the I/O */ + if ((val & mask) != 0) { + fail: + raise_exception_err_ra(env, EXCP0D_GPF, 0, retaddr); + } +} |